Co-reporter:Ran Duan;Xing Ai;Yayun Liu
The International Journal of Advanced Manufacturing Technology 2017 Volume 92( Issue 9-12) pp:3531-3540
Publication Date(Web):27 April 2017
DOI:10.1007/s00170-017-0360-8
In this study, micro-scale textures with a single linear groove parallel to cutting edge are fabricated on the rake face of the WC/Co cemented carbide tools. Dry cutting tests on medium carbon steels (AISI 1045 steels) are carried out with this rake-face textured tool (TT) and a conventional carbide tool (CT). Results show that derivative cutting, i.e., the additional cutting to the bottom side of the chip with the micro-surface textures on the tool surface, occurred in dry cutting of medium carbon steels with the micro-textured tools. Derivative cutting always causes the filling of chip in the surface textures, which leads to the increase of friction at the tool-chip interface, cutting forces, and hardness and deformation of chip. The texture edge far from the main cutting edge is engaged in the derivative cutting as a cutting edge; wear of this texture edge results in a greater negative rake angle, which is found to be beneficial to alleviating the derivative cutting.
Co-reporter:Yayun Liu, Lili Liu, Jianxin Deng, Rong Meng, ... Fengfang Wu
Ceramics International 2017 Volume 43, Issue 8(Volume 43, Issue 8) pp:
Publication Date(Web):1 June 2017
DOI:10.1016/j.ceramint.2017.02.074
The green ZrO2 ceramics were fabricated by cold isostatic pressing. Pulsed laser ablation with a wavelength of 1064 nm was performed to fabricate micro-scale textured grooves on the surface of green ZrO2 ceramics. The influence of laser parameters on surface quality was studied. The heat-affected zone around the machined grooves and micromorphology of laser-irradiated surface were investigated. Results showed that micro-scale textured grooves with a width of 30–50 µm and a depth of 15–50 µm on the green ZrO2 ceramic surfaces were successfully fabricated by pulsed laser ablation. The laser parameters had a profound influence on the surface quality of micro-scale textured grooves. Better surface quality could be obtained with frequency below 40 Hz, power below 6 W, and scanning velocity above 200 mm/s. A sintering layer was found on the laser-irradiated surfaces when frequency was above 60 Hz, power was above 10 W, and scanning velocity was below 150 mm/s. Analysis of this sintering layer revealed clear melting and resolidification of ZrO2 particles.
Co-reporter:Youqiang Xing, Jianxin Deng, Ze Wu, Fengfang Wu
Optics & Laser Technology 2017 Volume 93(Volume 93) pp:
Publication Date(Web):1 August 2017
DOI:10.1016/j.optlastec.2017.01.032
•Two kinds of micro-grooved textures are fabricated on Al2O3/TiC ceramic by laser.•Micro-grooved textures have a potential in increasing friction and reducing wear.•The small texture spacing is beneficial to increasing the friction coefficient.•AT-W sample shows the highest friction coefficient and the smallest wear depth.Two kinds of grooved textures with different spacing were fabricated on Al2O3/TiC ceramic surface by an Nd:YAG laser. The dry tribological properties of the textured samples were investigated by carrying out unidirectional rotary sliding friction and wear tests using a ball-on-disk tribometer. Results show that the laser textured samples exhibit higher friction coefficient and excellent wear resistance compared with the smooth sample under dry friction conditions. Furthermore, the texture morphology and spacing have a significant influence on the tribological properties. The sample with small texture spacing may be beneficial to increasing the friction coefficient, and the wavy-grooved sample exhibits the highest friction coefficient and shallowest wear depth. The increasing friction coefficient and anti-wear properties are attributed to the combined effects of the increased surface roughness, reduced real contact area, micro-cutting effect by the texture edges and entrapment of wear debris.
Co-reporter:Yayun Liu, Jianxin Deng, Fengfang Wu, Ran Duan, Xiang Zhang, Yunhe Hou
Wear 2017 Volumes 372–373() pp:91-103
Publication Date(Web):15 February 2017
DOI:10.1016/j.wear.2016.12.001
•WC/Co carbide tools with and without textured flank-face were made.•The wear resistance of tools with textured flank-face was improved.•The tools with grooves parallel to the main cutting edge were the most effective.•Textures on the flank face exhibited derivative-cutting phenomenon.•Derivative-cutting was beneficial to the decrease of flank wear of textured tools.Green ceramics are the ceramic compacts before sintering, and there is no metallurgical bonding force between the powder particles. Therefore, it can be machined by traditional mechanical processing. Machining of green ceramics represents an alternative way to other shaping process, and offers a high degree of flexibility and economic efficiency for the machining of ceramic parts. In this paper, surface texturing with different geometrical characteristics was made on the flank face of the WC/Co carbide tools. Dry cutting tests on the green alumina ceramics were carried out with these flank-face textured tools and a conventional WC/Co carbide tool, the wear resistance of these flank-face textured tools was investigated. Results showed that there was only mild wear on the rake face, while flank face revealed serious abrasive wear. The flank wear of the flank-face textured tools was significantly reduced compared with that of the conventional one, and the flank-face textured tools with micro-scale grooves on the flank face parallel to the main cutting edge (AT-1) had the most improved flank wear resistance. Mechanism responsible was found that the textures on the flank face exhibited derivative-cutting phenomenon during dry cutting of green alumina ceramics, which served as the removal of hard inclusion between the tool-workpiece interface. The derivative-cutting was found to be beneficial to the decrease of the flank wear of the flank-face textured tools. The textures on the flank faces can also be acted as storage for powder chip which can protect the texture groove from abrasion. Textures on flank face had no obvious effect on the roughness of machined green alumina ceramic surfaces.
Co-reporter:Kedong Zhang, Jianxin Deng, Zeliang Ding, Xuhong Guo, Lining Sun
Journal of Manufacturing Processes 2017 Volume 30(Volume 30) pp:
Publication Date(Web):1 December 2017
DOI:10.1016/j.jmapro.2017.10.018
In this paper, we investigated the effects of WS2 solid lubricant film and femtosecond laser-textures on improving the cutting performance of PVD TiAlN coated tools, which is crucial for dry cutting applications. To do this, nano-scale textures were fabricated on the rake face of WC/Co-based TiAlN coated tools using femtosecond laser technology, WS2 solid lubricant film was then deposited on to the conventional and nano-scale textured TiAlN coated surfaces by medium-frequency magnetron sputtering technique. The microstructures and fundamental properties of the laser textured and WS2 coated surfaces were assessed utilizing the analytical tools. Dry cutting experiments were carried out on hardened steel with the developed TiAlN coated tools, and the resulting friction and wear data were compared with those from the conventional one. These tests show that, as WS2 film has much smaller shear strength than TiAlN coatings, the lubrication of contact between the tool/chip interface is enhanced. This leads to a significant improvement in the dry cutting performance of WS2 coated specimens, showing reductions in cutting forces, cutting temperatures, friction coefficient and tool wear compared with that of the conventional TiAlN coated tool. Another, important, finding is nano-scale textures on the TiAlN coating surfaces can improve the effective life of the initial WS2 layer for a longer period than the untextured one due to the higher adhesive strength between the WS2 and textured TiAlN films. The possible mechanisms for the effects of WS2 solid lubricant film and femtosecond laser-textures are discussed.
Co-reporter:Kedong Zhang, Jianxin Deng, Shuting Lei, Xiaoming Yu
Surface and Coatings Technology 2016 Volume 291() pp:382-395
Publication Date(Web):15 April 2016
DOI:10.1016/j.surfcoat.2016.03.008
•We report the novel TiAlN coated samples with different-scale surface textures.•The nano- and micro-scale surface textures were investigated comparatively.•Friction tests versus AISI 316 austenitic stainless steel were carried out.•Effect of textures and MoS2 on tribological properties of coatings was studied.•The mechanism responsible for the improving performance was proposed.To improve the tribological properties of TiAlN coated surfaces, the effects of laser surface texturing (LST) and burnished MoS2 addition were investigated. Two types of surface textures were fabricated prior to TiAlN coating deposition: (i) nano-scale textures fabricated by femtosecond laser, and (ii) micro-scale textures fabricated by Nd:YAG laser. MoS2 powder was applied to conventional and micro-scale textured TiAlN coated surfaces. Thus, four different samples were fabricated: 1. TiAlN coated sample (CS), 2. nano-scale textured TiAlN coated sample (NCS), 3. TiAlN coated sample burnished with MoS2 (CS-M), and 4. micro-scale textured TiAlN coated sample burnished with MoS2 (MCS-M). The tribological properties were evaluated using a ball-on-disk tribometer at a load of 10–40 N and velocity of 2–10 mm/s. The results show that MoS2 addition and nano- or micro-scale grooves improve the tribological performance of TiAlN coatings. Nano-scale textures remarkably increase the wear life of TiAlN coatings, while it has no significant effect on the coefficient of friction (COF). MoS2 addition remarkably decreases the COF values, and micro-scale textures improve the effective life of the initial MoS2 layer for a longer period than the untextured one. The possible mechanisms for the effects of surface texture and burnished MoS2 are discussed.
Co-reporter:Kedong Zhang, Jianxin Deng, Rong Meng, Shuting Lei, Xiaoming Yu
International Journal of Refractory Metals and Hard Materials 2016 Volume 57() pp:101-114
Publication Date(Web):June 2016
DOI:10.1016/j.ijrmhm.2016.03.004
•Laser substrate pretreatment was prepared at different scanning speed 5–20 mm/s.•Effect of textures on anti-adhesive wear properties of coated tools was studied.•Wear tests and turning experiments against stainless steel were performed.•Wear protecting property of in-situ formed layer was conserved by laser texturing.•The scanning speed had a profound effect on the adhesive strength of the coatings.To improve the anti-adhesive wear properties of WC/Co-based TiAlN coatings, a laser substrate surface pretreatment was examined. The cemented carbide substrates were textured with a Nd:YAG laser, in three different scanning speeds, and then coated with a PVD TiAlN film. The anti-adhesive wear properties of each surface were evaluated via the ball-on-disk wear test and turning experiments. Additionally, characterization tests such as variable depth scratch test were also performed in order to verify the coating adhesiveness and to explain the results of the wear and machining tests. The results reveal that the anti-adhesive wear properties of the three TiAlN coated textured samples are significantly improved over that of the conventional one; the adhesion of TiAlN coatings is greatly improved by using Nd:YAG laser substrate pretreatment. Moreover, laser-scanning speed has a profound effect on the adhesion strength of the pretreated samples. In the experiments, the lowest scanning speed (5 mm/s) is most effective in providing a greater mechanical locking of the coatings upon the substrate and a more matching chemical property between substrate and coating materials, thus increasing the critical load of the coatings. Meanwhile, the adhered workpiece material layer is more stable on the pretreated sample irradiated at 5 mm/s. Hence, potential wear protecting properties of the in-situ formed layer can be conserved.
Co-reporter:Kedong Zhang, Jianxin Deng, Youqiang Xing, Shipeng Li, Huanhuan Gao
Applied Surface Science 2015 Volume 326() pp:107-118
Publication Date(Web):30 January 2015
DOI:10.1016/j.apsusc.2014.11.059
Highlights
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The micro-textured TiAlN coated tools were successfully fabricated by the combination of laser surface texturing technique and cathode arc-evaporation technique.
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Performance of the developed tools under full and starved fluid lubrication conditions was investigated.
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Cutting forces, friction coefficient, surface roughness of machined workpiece and tool wear were measured.
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The mechanisms responsible for reducing the friction and wear by surface texturing were discussed.
Co-reporter:Youqiang Xing, Jianxin Deng, Xingsheng Wang, Rong Meng
Wear 2015 Volumes 342–343() pp:1-12
Publication Date(Web):15 November 2015
DOI:10.1016/j.wear.2015.08.002
•Laser surface textures were prepared on the surface of Al2O3/TiC ceramic.•Tribological properties of samples with different solid lubricant types were studied.•Friction and wear properties of the ceramic and counter-ball were improved.•The PVD WS2/Zr coatings were more effective in protecting the textured ceramic.To improve the friction and wear properties of Al2O3/TiC ceramic tool material, laser surface textures combined with burnished MoS2 solid lubricants, burnished WS2 solid lubricants and magnetron sputtered WS2/Zr coatings by physical vapor deposition (PVD) methods were fabricated on its surface. The friction and wear tests were performed by dry sliding friction tests against AISI 1045 hardened steel balls using a ball-on-disk tribometer. The effect of the surface textures combined with muti-solid lubricant coatings on the tribological behavior of Al2O3/TiC ceramic was investigated. Results show that a combination of laser surface textures and solid lubricants can effectively improve the tribological properties of Al2O3/TiC ceramic surface and protect the counter-face of the ball. The burnished WS2 solid lubricants combined with surface textures are more effective in reducing the friction and wear compared with burnished MoS2 solid lubricants. The WS2/Zr coatings deposited on the textured sample show the best efficiency in improving the tribological properties compared with the textured samples with burnished MoS2 and WS2 solid lubricants. However, the ball sliding against the textured sample with burnished WS2 lubricants exhibits the smallest wear rate. In addition, the possible mechanisms of laser surface textures combined with different solid lubricant types were discussed.
Co-reporter:Shipeng Li, Jianxin Deng, Guangyuan Yan, Kedong Zhang, Guodong Zhang
Applied Surface Science 2014 Volume 309() pp:209-217
Publication Date(Web):1 August 2014
DOI:10.1016/j.apsusc.2014.05.012
Highlights
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A new coating of TiSiN–WS2 was deposited by AIP and MF magnetron sputtering.
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The deposition of WS2 layer increased the coating's adhesive strength.
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The tribological performance of TiSiN–WS2 coating was improved significantly.
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Increasing WS2 layer thickness can lead a greater improvement.
Co-reporter:Youqiang Xing, Jianxin Deng, Shipeng Li, Hongzhi Yue, Rong Meng, Peng Gao
Wear 2014 Volume 318(1–2) pp:12-26
Publication Date(Web):15 October 2014
DOI:10.1016/j.wear.2014.06.001
•WS2/Zr coated Al2O3/TiC cutting tools with and without nano-textures were made.•The cutting performance and tool wear of developed tools were improved.•The tools combined with nano-textures and WS2/Zr coatings were the most effective.•The lubricity has a strong correlation with geometries of textures.•The wear characteristics of different tools were elaborated.To improve the cutting performance and reduce the tool wear, novel Al2O3/TiC cutting tools were developed with coating and laser technologies: first, the WS2/Zr coated Al2O3/TiC ceramic cutting tool; second, nano-textured Al2O3/TiC ceramic cutting tools deposited with WS2/Zr composite soft-coatings. Dry cutting tests were carried out on hardened steel with the conventional and developed tools. The cutting force, cutting temperature, friction coefficient, and tool wear were measured. Results show that the WS2/Zr coated Al2O3/TiC cutting tools with and without nano-textures significantly improve the lubricity at the tool-chip interface; the cutting force, cutting temperature, friction coefficient and tool wear are reduced compared with the conventional tools; the nano-textured tools deposited with WS2/Zr composite soft-coatings are the most effective. In addition, the geometry of nano-textures has a profound effect on the lubricity, the WS2/Zr coated cutting tool with areal nano-textures is the most effective in improving the cutting performance and reducing the tool wear. The abrasive wear, chipping and adhesions are the predominant wear characteristics of conventional tools, the abrasive wear and coating flaking is for coated tools, and the adhesions at the tool tip is mainly for the coated tools with nano-textures.
Co-reporter:Youqiang Xing, Jianxin Deng, Yonghui Zhou, Shipeng Li
Surface and Coatings Technology 2014 Volume 258() pp:699-710
Publication Date(Web):15 November 2014
DOI:10.1016/j.surfcoat.2014.08.014
•Nano-textures and WS2/Zr soft-coatings were made on Al2O3/TiC ceramic surface.•Friction and wear behavior were improved by nano-textures and WS2/Zr soft-coatings.•The sample combined with nano-textures and WS2/Zr coatings was the most effective.•The possible friction reduction and wear resistant mechanisms were discussed.To improve the tribological properties of the solid contact surfaces, the surface micro/nano-texturing and thin film lubrication are two effective ways to alleviate adhesion, friction and wear of the counter-parts. In this paper, the nano-textures and WS2/Zr soft-coatings were made on the Al2O3/TiC ceramic surface by femtosecond laser technology and physical vapor deposition (PVD) method. The microstructural and fundamental properties of the nano-textures and WS2/Zr soft-coatings were examined, and the friction and wear properties of nano-textures, WS2/Zr soft-coatings and a combination of nano-textures and WS2/Zr soft-coatings on Al2O3/TiC ceramic surface were investigated by carrying out sliding friction tests. Results show that nano-textures increase the adhesion strength between the coatings and substrate; the friction coefficient and wear are reduced by the nano-textures and WS2/Zr soft-coatings, a combination of nano-textures and WS2/Zr soft-coatings shows the best efficiency in improving the tribological properties; meanwhile, the nano-textures significantly increase the wear life of initial WS2/Zr lubricant coatings. The possible effect mechanism of the nano-textures and WS2/Zr soft-coatings was discussed.
Co-reporter:Yunsong Lian, Jianxin Deng, Youqiang Xing, Shuting Lei, Xiaoming Yu
Applied Surface Science 2013 Volume 282() pp:518-524
Publication Date(Web):1 October 2013
DOI:10.1016/j.apsusc.2013.06.004
Highlights
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Periodic and uniform nanogratings have been fabricated on cemented carbide.
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Nanograting uniformity is largely determined by three factors in this research.
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Nanograting period increases gradually with the decrease of single pulse energy.
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Nanograting period increases gradually with the increase of scanning speed.
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Nanograting period maintains a fixed value under different scanning spacings.
Co-reporter:Jianxin Deng, Yunsong Lian, Ze Wu, Youqiang Xing
Surface and Coatings Technology 2013 Volume 222() pp:135-143
Publication Date(Web):15 May 2013
DOI:10.1016/j.surfcoat.2013.02.015
Nano-scale surface texturing was made on the rake face close to the main cutting edge of the WC/TiC/Co carbide tools with femtosecond laser, these textured tools were then deposited with WS2 solid lubricant coatings. Microstructural and fundamental properties of the textured tools deposited with and without WS2 coatings were examined. Dry cutting tests were carried out with the rake face textured tools (TT), the rake face textured tools deposited with WS2 coatings (TT-WS2), and the conventional carbide tools (CT). Results show that the cutting forces, the cutting temperature, and the friction coefficient at the tool-chip interface of the TT and TT-WS2 tools were significantly reduced compared with that of the conventional carbide tool (CT). The rake face textured tool deposited with WS2 coatings had the most improved cutting performance. The reduced contact length at the tool-chip interface was found to be the main reason for the decrease of friction of the TT rake face textured tool. The thin lubricating film of WS2 solid lubricant on the textured rake face of the TT-WS2 tool contributed to the decrease friction and adhesion between chip–tool interface. It is suggested that deposition of lubricating film on the textured rake face is an effective way to improve the cutting performance of conventional carbide tools in dry cutting.Highlights► WS2 coatings were deposited on the surface texturing of the carbide tools. ► The performance of untextured, textured and textured with WS2 tools were compared. ► The tools combined with texture and WS2\ coating exhibited better cutting performance.
Co-reporter:Youqiang Xing, Jianxin Deng, Xiuting Feng, Sheng Yu
Materials & Design 2013 52() pp: 234-245
Publication Date(Web):
DOI:10.1016/j.matdes.2013.05.077
Co-reporter:Deng Jianxin, Zhang Hui, Wu Ze, Lian Yunsong, Xing Youqiang, Li Shipeng
International Journal of Refractory Metals and Hard Materials 2012 Volume 35() pp:17-26
Publication Date(Web):November 2012
DOI:10.1016/j.ijrmhm.2012.03.011
The unlubricated friction and wear behaviors of Al2O3/TiC ceramic tool materials were evaluated in ambient air at temperature up to 800 °C by high temperature tribological tests. The friction coefficient and wear rates were measured. The microstructural changes and the wear surface features of the ceramics were examined by scanning electron microscopy. Results showed that the temperature had an important effect on the friction and wear behaviors of this Al2O3 based ceramic. The friction coefficient decreased with the increase of temperature, and the Al2O3/TiC ceramics exhibited the lowest friction coefficient in the case of 800 °C sliding operation. The wear rates increased with the increase of temperature. During sliding at temperature above 600 °C, oxidation of the TiC is to be expected, and the formation of lubricious oxide film on the wear track is beneficial to the reduction of friction coefficient. The wear mechanism of the composites at temperature less than 400 °C was primary abrasive wear, and the mechanisms of oxidative wear dominated in the case of 800 °C sliding operation.
Co-reporter:Ze Wu, Jianxin Deng, Youqiang Xing, Hongwei Cheng, Jun Zhao
Materials & Design 2012 41() pp: 142-149
Publication Date(Web):
DOI:10.1016/j.matdes.2012.05.012
Co-reporter:Wu Ze;Deng Jianxin;Chen Yang
The International Journal of Advanced Manufacturing Technology 2012 Volume 62( Issue 9-12) pp:943-951
Publication Date(Web):2012 October
DOI:10.1007/s00170-011-3853-x
Surface textures were made using laser on the rake or flank face of the cemented carbide (WC/Co) inserts. Molybdenum disulfide solid lubricants were filled into the textured grooves to form self-lubricating textured tools. Dry cutting tests on Ti-6Al-4V were carried out with these self-lubricating textured tools and conventional tool. The machining performance was assessed in terms of the cutting forces, cutting temperature, chip thickness ratio, friction coefficient at the tool–chip interface, and tool wear. Results show that the cutting forces and cutting temperature of the self-lubricating textured tools were reduced compared with that of the conventional tool. The application of the self-lubricating textured tool with elliptical grooves on its rake face can reduce the tool–chip friction coefficient and the chip thickness ratio. The tool life of the textured tools is improved compared with that of the conventional tool. The effectiveness of the self-lubricating textured tools in improving cutting performance is related to the cutting parameter.
Co-reporter:Ze Wu, Jianxin Deng, Hui Zhang, Yunsong Lian, Jun Zhao
Wear 2012 Volumes 292–293() pp:135-143
Publication Date(Web):15 July 2012
DOI:10.1016/j.wear.2012.05.021
Laser surface textures were made on the surfaces of WC/Co cemented carbide disks. Dry sliding friction and wear tests against titanium alloy balls were carried out with four kinds of samples for comparison. Results showed that the smooth surface burnished with solid lubricants cannot effectively improve the frictional performance of the cemented carbide, the textured surface without solid lubricants has a worse tribological behavior compared with the smooth surface, and only the surface texturing combined with solid lubricants shows the benefit in improving the tribological properties. The average friction coefficient and temperature of the textured surface filled with solid lubricants are both reduced compared with those of the smooth surface. Operation with textured surface filled with solid lubricants can also reduce the width of wear scars on the cemented carbide disks and wear loss of titanium alloy balls.Highlights► Surface texturing was fabricated on cemented carbide disks. ► Tribological behavior of four kinds of samples against Ti6Al4V was investigated. ► Only the TSL sample can improve the tribological properties of cemented carbide. ► The friction coefficients and temperatures are reduced in operation with TSL sample. ► The TSL sample can also reduce wear loss of the titanium alloy.
Co-reporter:Jianxin Deng;Pei Yan;Ze Wu
Chinese Journal of Mechanical Engineering 2012 Volume 25( Issue 6) pp:1218-1223
Publication Date(Web):2012 November
DOI:10.3901/CJME.2012.06.1218
MoS2 metal composite coatings have been successful used in dry turning, but its suitability for dry drilling has not been yet established. Therefore, it is necessary to study the friction and wear behaviors of MoS2/Zr coated HSS in sliding wear and in drilling processes. In the present study, MoS2/Zr composite coatings are deposited on the surface of W6Mo5Cr4V2 high speed steel(HSS). Microstructural and fundamental properties of these coatings are examined. Ball-on-disc sliding wear tests on the coated discs are carried out, and the drilling performance of the coated drills is tested. Test results show that the MoS2/Zr composite coatings exhibit decreases friction coefficient to that of the uncoated HSS in sliding wear tests. Energy dispersive X-ray(EDX) analysis on the wear surface indicates that there is a transfer layer formed on the counterpart ball during sliding wear processes, which contributes to the decreasing of the friction coefficient between the sliding couple. Drilling tests indicate that the MoS2/Zr coated drills show better cutting performance compared to the uncoated HSS drills, coating delamination and abrasive are found to be the main flank and rake wear mode of the coated drills. The proposed research founds the base of the application of MoS2 metal composite coatings on dry drilling.
Co-reporter:Jianxin Deng, Wenlong Song, Hui Zhang, Pei Yan, Aihua Liu
Wear 2011 Volume 270(9–10) pp:666-674
Publication Date(Web):4 April 2011
DOI:10.1016/j.wear.2011.01.031
Micro-holes were made on the surface of WC/TiC/Co carbide, MoS2 solid lubricants were filled into these micro-holes. Reciprocating sliding tests and dry cutting tests were carried out with this carbide tools. Results showed that the friction coefficient of conventional carbide is much higher than that of the carbide embedded with solid lubricants in sliding tests. The cutting forces, temperature, and friction coefficient at the tool–chip interface of the tool embedded with solid lubricants were reduced compared with that of the conventional tool. Two mechanisms responsible were found, the first one is explained as the formation of self-lubricating film at the tool–chip interface, which was released from the micro-hole and smeared on the rake, and served as lubricating additive; the other one was explained by the reduced contact length at the tool–chip interface, which contributes to the decrease of direct contact area between the chip and rake face.Research highlights► Micro-holes filled MoS2 solid lubricants were made on the surface of the cemented carbide tool. ► The cutting performance of this tool was improved compared with that of the conventional one. ► Two mechanisms responsible were found. It is suggested that this tool is an effective way to decrease friction during dry cutting processes.
Co-reporter:Deng Jianxin, Zhang Hui, Wu Ze, Liu Aihua
International Journal of Refractory Metals and Hard Materials 2011 Volume 29(Issue 5) pp:631-638
Publication Date(Web):September 2011
DOI:10.1016/j.ijrmhm.2011.04.011
The friction and wear behavior of the polycrystalline diamond (PCD) were evaluated in ambient air at temperatures up to 700 °C using a ball-on-disk high temperature tribometer. The wear surface features of the PCD were examined by scanning electron microscopy. Energy dispersive X-ray analysis was used to investigate the chemical composition. XRD experiments were performed to study the crystal structure of the PCD specimens at different temperatures. Results showed that the friction coefficient of the PCD is different depending on the temperature, and decreases with the increase of temperature. The PCD exhibited the lowest friction coefficient of approximately 0.16 in the case of 700 °C sliding operation. The difference of the worn surface features of the PCD after sliding at different temperatures is related to the chemical transformation during sliding wear tests. The surface damage of the PCD appears to happen around 600 °C accompanied by extensive Co phase extrusion out of PCD. Numerous micro-cracks both at the grain boundaries and in the grains are observed with the increase of temperature to 700 °C. At this temperature, surface graphitization of diamond is to be expected, and the formation of graphite on the wear track is beneficial to the reduction of friction coefficient.Research highlights► The friction coefficient of the PCD is different depending on the temperature, and decreases with the increase of temperature. ► The surface damage of the PCD appears to happen around 600 °C accompanied by extensive Co phase extrusion out of PCD. ► Numerous micro-cracks both at the grain boundaries and in the grains are observed with the increase of temperature to 700 °C.
Co-reporter:Deng Jianxin, Zhou Jiantou, Zhang Hui, Yan Pei
Wear 2011 Volume 270(7–8) pp:520-527
Publication Date(Web):10 March 2011
DOI:10.1016/j.wear.2011.01.006
Dry turning tests were carried out on Cr12Mn5Ni4Mo3Al precipitation hardening semi-austenitic stainless steels with two kinds of carbide tools (WC/Co and WC/TiC/Co). The tool wear, the cutting forces, and the cutting temperature were measured. The element diffusion from the Cr12Mn5Ni4Mo3Al stainless steel to carbide tools (vice versa) at temperatures up to 600 °C was examined. The morphology of the diffusion couples was detected by SEM. Results showed that WC/TiC/Co carbide tools are more suitable for the machining of Cr12Mn5Ni4Mo3Al stainless steel. The flank wear, the cutting forces, and the cutting temperature of WC/TiC/Co tool are smaller than that of the WC/Co one under the same test conditions. There was evidence of element diffusion from the tool rake face to the adhering chip (vice versa), which leads to the tool element loss and microstructure change. The wear mechanisms of the carbide tools in dry machining of Cr12Mn5Ni4Mo3Al stainless steel were mainly abrasive wear, adhesion and diffusion wear.Research highlights▶ Dry turning tests were carried out on Cr12Mn5Ni4Mo3Al precipitation hardening semi-austenitic stainless steels with two kinds of carbide tools. ▶ Results showed that the WC/TiC/Co carbide tools are more suitable for the machining of Cr12Mn5Ni4Mo3Al stainless steel, and have higher flank wear resistance over the WC/Co one. ▶ There was evidence of diffusion of W and Co elements of the carbide tool to the Cr12Mn5Ni4Mo3Al stainless steels, and Fe, Cr, Mn, and Mo of the Cr12Mn5Ni4Mo3Al stainless steel to the carbide tool when the cutting temperature is above 400 °C. ▶ The wear mechanisms of the carbide tools in dry machining of Cr12Mn5Ni4Mo3Al stainless steel were mainly abrasive wear, adhesion and diffusion wear.
Co-reporter:Jianxin Deng, Dongling Yun, Houmin Zhou, Yuanqiang Tan
Ceramics International 2010 Volume 36(Issue 1) pp:299-306
Publication Date(Web):January 2010
DOI:10.1016/j.ceramint.2009.09.003
Abstract
The nozzle is the most critical part in the coal-water-slurry (CWS) boilers. Ceramics being highly wear resistant have great potential as CWS nozzle materials. In this paper, Al2O3/(W,Ti)C + Al2O3/TiC layered ceramics (LN1, LN2, and LN3) with different thickness ratios among constituent layers were developed to be used as nozzles in CWS boilers. CWS burning tests in a boiler with these nozzles were carried out. The erosion wear behavior of the layered nozzles was investigated and compared with an unstressed reference nozzle (N5). Results showed that the layered ceramic nozzles exhibited an apparent increase in erosion wear resistance over the unstressed reference one. The mechanisms responsible were found to be that layered structure in the CWS nozzles can improve the hardness and fracture toughness of the external layer, and reduce the temperature gradients and the thermal stresses at the exit of the nozzle during CWS burning processes. It is suggested that layered structures in ceramic nozzles is an effective way to improve the erosion wear resistance over the stress-free ceramic nozzles in industrial CWS boilers.
Co-reporter:Deng Jianxin, Duan Zhenxing, Yun Dongling, Zhang Hui, Ai Xing, Zhao Jun
Materials Science and Engineering: A 2010 527(4–5) pp: 1039-1047
Publication Date(Web):
DOI:10.1016/j.msea.2009.09.020
Co-reporter:Jianxin Deng, Zeliang Ding, Houming Zhou, Yuanqiang Tan
International Journal of Refractory Metals and Hard Materials 2009 Volume 27(Issue 5) pp:919-926
Publication Date(Web):September 2009
DOI:10.1016/j.ijrmhm.2009.05.007
Ceramics, cemented carbides, and metals were prepared to be used as nozzles in CWS boilers. CWS burning tests in a boiler with these nozzles were carried out. The erosion wear resistance of these nozzles was compared by determining their erosion rates and hole diameter variation. Results showed that the life of the ceramic nozzles is about 30 times high than that of the metal nozzles. The wear types at the nozzle wall surface differed in various positions. The nozzle center wall section suffers form abrasive impact under low impact angles, and the damage at the center wall mainly occurs by plowing and plastic deformation for metals, and by polishing action for carbides and ceramics. The primary wear mechanisms at the exit of ceramic nozzle exhibited thermal shock damage with chipping owing to the greater thermal stresses.
Co-reporter:Deng Jianxin, Yun Dongling, Tan Yuanqiang
International Journal of Refractory Metals and Hard Materials 2009 Volume 27(Issue 4) pp:734-739
Publication Date(Web):July 2009
DOI:10.1016/j.ijrmhm.2008.12.004
Al2O3/(W0.7Ti0.3)C + Al2O3/TiC multilayered ceramic nozzles (N1, N2, N3 and N4) with different thickness ratios among constituent layers were produced by hot-pressing. The value of the residual stress inside the layered nozzle during fabricating process was calculated by means of the finite element method. The mechanical properties at the surface layer of these layered materials were measured, the microstructure was examined. The wear behaviors of the multilayered nozzles were investigated and compared with an unstressed reference nozzle (N5). Results showed that the multilayered nozzles had superior erosion wear resistance to that of the stress-free one. The erosion wear resistance of the layered nozzles was influenced by the thickness ratio among constituent layers. The N4 nozzle with thickness ratio of two between adjacent layers exhibited higher erosion wear resistance over the N1, N2 and N3 nozzles.
Co-reporter:Jianxin Deng, Jianhua Liu, Zeliang Ding, Ming Niu
Materials & Design (1980-2015) 2008 Volume 29(Issue 9) pp:1828-1834
Publication Date(Web):October 2008
DOI:10.1016/j.matdes.2008.03.007
Medium-frequency magnetron sputtered PVD ZrN coatings (ZrN, ZrN/Zr) were deposited on YT15 (WC + 15%TiC + 6%Co) cemented carbide. Microstructural and fundamental properties of these ZrN coatings were examined. Unlubricated sliding wear tests against hardened steel using the ring-block method were carried out with these ZrN coatings in air atmosphere. The friction coefficient and wear rates were measured with varying sliding speeds and normal loads. The wear surface features of the coatings were examined by scanning electron microscopy. Results showed that the deposition of the PVD ZrN coatings onto the YT15 cemented carbide causes great increase in surface hardness. The ZC-1 specimen (ZrN/YT15 without interlayer) has the highest surface hardness, while the ZC-2 (ZrN/Zr/YT15 with Zr interlayer) specimen showed the highest adhesion load for the coatings to the substrate. The ZrN coatings exhibit improved friction behavior and wear resistance to that of the YT15 cemented carbide. The specimens with a Zr interlayer (ZC-2) have higher wear resistance over the one without Zr interlayer (ZC-1). The wear patterns of the ZrN coatings observed were mainly abrasive wear at low sliding speed, while severe adhesive wear was found to be predominant at high sliding speed. Cracks and delamination fracture of the ZrN coatings from the substrate were observed at the highest load applied.
Co-reporter:Deng Jianxin, Li Yousheng, Song Wenlong
Wear 2008 Volume 265(11–12) pp:1776-1783
Publication Date(Web):26 November 2008
DOI:10.1016/j.wear.2008.04.024
The element diffusion from the Ti–6Al–4V titanium alloy to WC/Co carbide tools (vice versa) at temperatures up to 800 °C was examined. The morphology of the diffusion couples was detected by SEM. Dry turning tests on Ti–6Al–4V alloy were carried out with WC/Co carbide tools. Results showed that W and Co elements did not greatly penetrate into the Ti–6Al–4V alloy at 400 °C; while at 600 °C, W and Co diffused a long way into the Ti–6Al–4V alloy, and the penetrating depth reached 20 μm at 800 °C. The hardness near the interface of the diffusion couples is lower than those far away from the interface owing to element diffusions. The element diffusion from the Ti–6Al–4V to the WC/Co carbide tools (vice versa) through the tool–chip interface in machining processes leads to a composition change of the tool substrate, which may accelerate the tool wear.
Co-reporter:LiLi Liu;Yi Wang;LiNa Zhu
Science China Technological Sciences 2008 Volume 51( Issue 1) pp:77-84
Publication Date(Web):2008 January
DOI:10.1007/s11431-008-0003-2
The idea of functionally gradient material (FGM) theory was used to design ceramic nozzle based on the erosion wear behaviors of the ceramic nozzles and the outstanding properties of FGM. The purpose is to reduce the tensile stress at the entry region of the nozzle during sand blasting processes. The design theory and methods of gradient ceramic nozzle were proposed. The physical, micromechanical, and composition distribution models of gradient ceramic nozzle were established. The optimum composition distribution of the gradient ceramic nozzle material was determined from the solution of the multi-objective optimization calculation by constructing the models of the composition distribution versus the structural integrity of the compact in fabricating process. Results showed that compressive residual stresses appeared at the entry area of the gradient ceramic nozzle. The optimized component distribution exponent p is 0.5. An SiC/(W,Ti)C gradient ceramic nozzle material was synthesized by hot-pressing according to the design result. Results showed that the surface Vickers hardness of the FGM-1 gradient ceramic nozzle materials was greatly improved in comparison with that of the other layers.
Co-reporter:Deng Jianxin, Liu Jianhua, Zhao Jinlong, Song Wenlong, Niu Ming
Wear 2008 Volume 264(3–4) pp:298-307
Publication Date(Web):4 February 2008
DOI:10.1016/j.wear.2007.03.014
Medium-frequency magnetron sputtered PVD ZrN coatings were deposited on YG6 (WC + 6 wt% Co) cemented carbide. Microstructural and fundamental properties of the ZrN coatings were examined. Sliding wear tests against hardened steel using the ring-block method and dry machining tests on hardened steel were carried out with these coated materials. The friction coefficient and wear rates were measured. The wear surface features of the coatings were examined by scanning electron microscopy. Results showed that the PVD ZrN coatings onto the cemented carbide substrate show high hardness and good adhesion with the substrate. The friction coefficient of the sliding couples increased with the applied load and the sliding distance. Failures of the ZrN coating occur down to the carbide substrate under high load conditions or with long sliding distance in sliding wear tests, and are accompanied by the extensive abrasive wear on the substrate owing to the wear debris. The ZrN coated tools showed much better cutting performance compared to the YG6 uncoated carbide, which is connected with their large hardness increase, and good abrasive wear resistance. Abrasive wear was found to be the predominant flank wear mechanism for the ZrN coated tools. While the mechanisms responsible for the rake wear were determined to be adhesion.
Co-reporter:Jianxin Deng, Lili Liu, Mingwei Ding
Materials & Design (1980-2015) 2007 Volume 28(Issue 7) pp:2099-2105
Publication Date(Web):2007
DOI:10.1016/j.matdes.2006.05.025
A SiC/(W,Ti)C ceramic nozzle with gradient structures was produced by hot pressing. The purpose is to reduce the tensile stress at the entry region of the nozzle in abrasive air-jet. The sand erosion performance of this kind gradient ceramic nozzle caused by abrasive particle impact was investigated by abrasive air-jets in comparison with the common one. Results showed that the gradient ceramic nozzles exhibited an apparent increase in erosion wear resistance over the common ceramic nozzles. The mechanism responsible was explained as the formation of compressive residual stresses in nozzle entry region in fabricating process of the gradient ceramic nozzles, which may partially counteract the tensile stresses resulting from external loadings. It is indicated that gradient structures in ceramic nozzles is an effective way to improve the erosion wear resistance of common ceramic nozzles.
Co-reporter:Zeliang Ding, Jianxin Deng, Jianfeng Li
Materials & Design (1980-2015) 2007 Volume 28(Issue 5) pp:1531-1538
Publication Date(Web):2007
DOI:10.1016/j.matdes.2006.02.020
In this study, Al2O3/(W,Ti)C ceramic, WC/Co cemented carbide, and 1Cr18Ni9Ti stainless steel were produced to be used as nozzle materials in coal water slurry (CWS) industry boilers. Coal water slurry burning tests with these nozzles were carried out. The wear surface features of the nozzles made from these materials were examined. The results showed that the wear mechanisms of nozzles varied from entry to exit. The material removal of Al2O3/(W,Ti)C ceramic nozzle in CWS atomizing and burning is attributed to a mixed mode damage by brittle fracture, polishing, thermal cracking and chipping. The nozzle entry section appears to be entirely brittle in nature with evidence of large scale-chipping. The centre bore area showed a polishing effect with a very smooth surface. While the exit section exhibits cracking owing to the large thermal shock. Examination of the eroded bore surface of the WC/Co cemented carbide nozzles demonstrated that the wear occurred through preferential removal of the metal binder (Co) followed by pluck-out of the exposed WC grains at the entry zone, while the center and the exit zone showed polishing action. The primary wear mechanisms of 1Cr18Ni9Ti stainless steel nozzle exhibited plastic deformation at the entry zone, and plowing and micro-cutting at the other zones by the eroded particles.
Co-reporter:Jianxin Deng, Lili Liu, Xuefeng Yang, Jianhua Liu, Junlong Sun, Jinlong Zhao
Materials & Design (1980-2015) 2007 Volume 28(Issue 3) pp:757-764
Publication Date(Web):2007
DOI:10.1016/j.matdes.2005.12.003
Al2O3/TiC ceramic composites with the additions of CaF2 solid lubricants were produced by hot pressing. Sliding wear tests against cemented carbide and dry machining tests on hardened steel were performed on these ceramic composites. Results showed that the ceramic composites exhibited self-lubricating property both in sliding wear tests and in machining processes. Scanning electron microscopy observations showed that a self-tribofilm was consistently formed on the wear surfaces, and the composition of the self-tribofilm was found to be mainly CaF2 solid lubricants. This self-tribofilm was formed by the releasing and smearing of CaF2 solid lubricants on the wear surface, acted as a lubricating additive between the sliding couple or on the tool–chip interface, protected the ceramics from severe wear by brittle microfracture, and significantly reduced the friction coefficient.
Co-reporter:Deng Jianxin, Liu Lili, Ding Mingwei
Materials Science and Engineering: A 2007 Volume 444(1–2) pp:120-129
Publication Date(Web):25 January 2007
DOI:10.1016/j.msea.2006.08.090
In sand blasting processes, the nozzle entry region suffers form severe abrasive impact, which may cause large tensile stress and lead to an increased erosion wear at the nozzle entry area. In this paper, SiC/(W,Ti)C laminated ceramic nozzles were produced by hot pressing. The purpose is to reduce the tensile stress at the entry region of the nozzle. Due to the different thermal expansion coefficients and shrinkage of the SiC and (W,Ti)C solid-solution, the entry region of the SiC/(W,Ti)C laminated ceramic nozzles in the fabricating process exhibit a compressive residual stress. The value of this residual stress was calculated by means of the finite element method. The erosion wear behaviour of the laminated ceramic nozzle and of a stress-free nozzle, with the same composition, was assessed by dry sand blasting. Results showed that the laminated ceramic nozzles have superior erosion wear resistance to that of the homologous stress-free nozzles. The mechanism responsible was explained as the formation of compressive residual stresses in nozzle entry region in fabricating process of the laminated ceramic nozzles, which may partially counteract the tensile stresses resulting from external loadings, and leads to an improvement of erosion wear resistance. It is indicated that laminated structures in ceramic nozzles is an effective way to improve the erosion wear resistance of the stress-free nozzles.
Co-reporter:Deng Jianxin, Ding Zeliang, Zhao Jun, Li Jianfeng, Cao Tongkun
Ceramics International 2006 Volume 32(Issue 5) pp:499-507
Publication Date(Web):2006
DOI:10.1016/j.ceramint.2005.03.031
Abstract
Al2O3/TiC, Al2O3/Ti(C,N), Al2O3/(W,Ti)C, and Al2O3/SiCw alumina-based composites, which provided a reasonably wide range of mechanical properties and microstructure, were produced by hot pressing. The unlubricated friction and wear behaviors of these composites against cemented carbide were studied in air atmosphere using the ring-block method. The friction coefficient and wear rates were measured, and the wear mechanisms were discussed in relation to mechanical properties and microstructure. Results showed that additions of TiC, Ti(C,N), (W,Ti)C, or SiCw to the Al2O3 matrix increased the flexural strength, fracture toughness, and hardness compared to the monolithic Al2O3 matrix. The friction coefficient showed a downward trend with the increasing of the sliding speed, and decreased dramatically with increasing applied load for all the alumina-based composites. The Al2O3/TiC composite showed the highest wear rate, and the Al2O3/SiCw the lowest one under identical test conditions. The higher wear resistance of Al2O3/SiCw composite corresponded to its higher fracture toughness and hardness.
Co-reporter:Jianxin Deng, Xihua Zhang, Pingzhang Niu, Lili Liu, Jinghai Wang
Tribology International 2006 Volume 39(Issue 3) pp:274-280
Publication Date(Web):March 2006
DOI:10.1016/j.triboint.2004.07.026
Monolithic B4C, Al2O3/(W,Ti)C and Al2O3/TiC/Mo/Ni ceramic composites, which provided a reasonably wide range of mechanical properties and microstructure, were produced to be used as nozzles materials. The erosion wear of the nozzle caused by abrasive particle impact was compared with dry sand blasting by determining the cumulative mass loss of the nozzles made from these materials. Results showed that the hardness of the nozzle material plays an important role with respect to its erosion wear. On the nozzle entry bore section, the B4C nozzle appears to be entirely brittle in nature with the evidence of large scale-chipping, and exhibited a brittle fracture induced removal process. While the erosion mechanism of Al2O3/TiC/Mo/Ni nozzle appeared to be a preferential removal of the metal binder followed by pluck out of the undermined Al2O3 and TiC grains under the same test conditions. On the nozzle center bore zone, the B4C nozzle fails in a highly brittle manner, and there are lots of obvious micro-cracks and small pits located on this area. While the primary wear mechanisms of Al2O3/TiC/Mo/Ni nozzle is plowing and micro-cutting by the abrasive particles. Both types of material removal model seem to be occurred for the Al2O3/(W,Ti)C nozzle.
Co-reporter:Deng Jianxin, Yang Xuefeng, Wang Jinghai
Materials Science and Engineering: A 2006 Volume 424(1–2) pp:347-354
Publication Date(Web):25 May 2006
DOI:10.1016/j.msea.2006.03.036
Al2O3/TiC/Mo/Ni ceramic composites were produced by hot-pressing for the use of wire drawing dies. The fundamental properties of these ceramic die materials were examined. Wire drawing tests were carried out on the 65Mn steel wire with these ceramic dies. Finite element method (FEM) was used as a means of numerically evaluating stress and its distribution inside the ceramic drawing dies. Worn bore surfaces of the ceramic drawing dies were examined by scanning electron microscopy (SEM). The wear mechanisms of the ceramic drawing dies were investigated. Detailed observations and analyses of the die wear surface have revealed that the most common failure of the ceramic drawing die is the wear at its approach zone. FEM analysis showed that the compressive stresses on both sides of the corners at the approach zone are higher than those of other parts of the ceramic drawing die. Abrasive and adhesive wear were found to be the predominant wear mechanisms through the whole approach zone owing to the greater compressive stresses. Examination of the center bore surface at the die bearing zone of the ceramic drawing dies demonstrated that the wear occurred by light abrasive, no adhesion wear was observed.
Co-reporter:Deng Jianxin, Ding Zeliang, Yuan Dongling
Materials Science and Engineering: A 2006 Volume 417(1–2) pp:1-7
Publication Date(Web):15 February 2006
DOI:10.1016/j.msea.2005.10.058
Al2O3/(W, Ti)C ceramic composites were prepared for the use of coal–water–slurry (CWS) nozzles in industry boilers. The erosion rates of the CWS ceramic nozzles were measured. Eroded bore surfaces of the nozzles was examined by scanning electron microscopy. Finite element method (FEM) was used as a means of numerically evaluating temperature, temperature gradient, thermal stress and its distribution inside the ceramic nozzle. Results showed that the primary wear mechanisms of the CWS ceramic nozzle exhibited polishing action in the inner center hole and thermal shock damage with chipping at exit. The temperature, temperature gradient and thermal stress at exit surfaces of the CWS ceramic nozzle were higher than those of other parts of the nozzle. Greater temperature gradient and higher thermal stress were the main reason that caused the failure of the exit surface of the CWS ceramic nozzle.
Co-reporter:Youqiang Xing, Jianxin Deng, Guodong Zhang, Ze Wu, Fengfang Wu
Journal of Manufacturing Processes (April 2017) Volume 26() pp:31-43
Publication Date(Web):1 April 2017
DOI:10.1016/j.jmapro.2017.01.006
Carbon fiber reinforced carbon and silicon carbide matrix composites (C/C-SiC) have a great potential in industrial applications due to their high friction coefficient and wear resistance, however, few published researches have studied systematically on the drilling of C/C-SiC composites, and the machinability can be problematic when drilling due to their anisotropy. Therefore, to reduce the surface damages of the drilled hole on unidirectional C/C-SiC composites, the drilling experiments with supported graphite plate are carried out systematically with brazed diamond drills, and the results are compared with that without supported graphite plate. The effect of process parameters on thrust force, delamination factor, hole surface quality and tool wear is investigated. Results show that the drilling with supported graphite plate improves the surface integrity of drilled hole compared with that without supported graphite plate. The thrust force increases with the reduced cutting speed and increasing feed rate. High spindle speed and low feed rate are effective in reducing the delamination factor and improving the drilled hole quality. Meanwhile, it is found that the surface damages and damage mechanisms of the drilled hole are influenced by the fiber orientation and cutting direction. Finally, the wear mechanisms of the drills with different process parameters are analyzed.
