Co-reporter:Alateng Shaga, Ping Shen, Li-Guang Xiao, Rui-Fen Guo, Ya-Bing Liu, Qi-Chuan Jiang
Materials Science and Engineering: A 2017 Volume 708(Volume 708) pp:
Publication Date(Web):21 December 2017
DOI:10.1016/j.msea.2017.09.114
Novel bio-inspired ZL205A/SiC composites with a lamellar-interpenetrated structure were successfully fabricated via gas-pressure infiltration of a commercial ZL205A alloy into freeze-cast porous SiC scaffolds. The influences of initial ceramic content (20, 30 and 40 vol%) on the microstructure and damage-tolerance behavior of the resultant composites as well as their toughening mechanism were investigated. With an increase in the ceramic content in the composite, the flexural strength and fracture toughness in the longitudinal direction gradually decreased; whereas, in the transverse direction they showed a first increase and then decrease but their elastic modulus increased. The composites displayed significant damage-tolerance anisotropy, with higher strength and toughness in the longitudinal direction (parallel to the lamellae) than that in the transverse direction (perpendicular to the lamellae). In the longitudinal bending, the ZL205A/20 vol%SiC composite exhibited the maximum flexural strength (760 MPa) and the largest fracture toughness (33.0 MPa m1/2). The excellent damage tolerance of the composites was attributed to multiple toughening mechanisms such as plastic deformation in the matrix alloy, crack blunting, deflection and branching, and uncracked-ligament bridging of the ductile alloy layers. However, in the transverse bending, the crack propagated along the ceramic layer in the composites and thus greatly weakened their damage-tolerance capability.
Co-reporter:Bo Yang, Ping Shen, Lian-Teng Yu, Rui-Fen Guo, Qi-Chuan Jiang
Scripta Materialia 2017 Volume 141(Volume 141) pp:
Publication Date(Web):1 December 2017
DOI:10.1016/j.scriptamat.2017.07.021
We report a novel strategy for rapid joining of yttria-doped ZrO2 and Ni at 1373 K in a vacuum without using any brazing filler or other types of interlayer. Electrochemically-driven diffusion bonding was established at the Ni–ZrO2 interface by applying an external electric power, and the interfacial chemistry was readily manipulated by altering the current polarity and intensity. The underlying mechanisms were addressed based on the considerations of current-induced oxygen ion movement and atomic diffusion and reaction.Download high-res image (334KB)Download full-size image
Co-reporter:Rui-Fen Guo, Ping Shen, Shi-Xin Li, Alateng Shaga, Qi-Chuan Jiang
Ceramics International 2017 Volume 43, Issue 9(Volume 43, Issue 9) pp:
Publication Date(Web):15 June 2017
DOI:10.1016/j.ceramint.2017.02.133
Al−7Si−5Cu/Al2O3−ZrO2 composites with nacre-like structures were prepared via ice-templating and gas pressure infiltration techniques. The composites were subsequently heat-treated at 850 °C for 0, 30, 60, 90 and 120 min to regulate the interfacial reaction between Al and ZrO2. The yield of larger (Al1−m, Sim)3Zr and ZrSi2 phases increased with longer dwell times. The compressive strength initially increased and then decreased. The highest strength was observed in composites treated for 60 min and reached 1600±40, 1261±30 and 1033±22 MPa at temperatures of 20, 150 and 300 °C, respectively. These values increased by 30−40% as compared to those of the non-treated counterparts and were 2-, 5- and 12-fold more than those of the matrix alloy, respectively, which is demonstrative of the material's excellent load-bearing capacity, particularly at elevated temperatures.
Co-reporter:Laixin Shi, Ping Shen, Dan Zhang, Qichuan Jiang
Applied Surface Science 2016 Volume 377() pp:340-348
Publication Date(Web):30 July 2016
DOI:10.1016/j.apsusc.2016.03.162
Highlights
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The wettability improves with increasing Mg concentration and temperature.
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Reaction product zone consists of layered structures relating with Mg concentration.
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Formation of MgAl2O4 and MgO at the interface does not promote the wettability.
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Formation of Mg2Si plays a dominant role in promoting the wettability.
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Anomalous recession of the triple line was mainly due to diminishing Mg in the alloy.
Co-reporter:Alateng Shaga, Ping Shen, Rui-Fen Guo, Qi-Chuan Jiang
Ceramics International 2016 Volume 42(Issue 8) pp:9653-9659
Publication Date(Web):June 2016
DOI:10.1016/j.ceramint.2016.03.052
Silicate-bonded porous SiC scaffolds with lamellar structures were prepared by freeze casting and liquid-phase sintering. It was found that the viscosity and solidification velocity of SiC water-based slurries with 30 vol% solid loading decreased with increasing Al2O3–MgO (AM) addition. As the AM content increased from 10 to 30 wt%, the lamellae of the sintered scaffolds became denser and the porosity decreased from 69±0.5% to 62±0.5%, while the compressive strength improved from 25±2 to 51±2 MPa. The dynamics of pressureless infiltration for an Al–12 Si–10 Mg alloy on the SiC porous scaffold was measured and the composites with lamellar-interpenetrated structures were successfully produced. Both the compressive strength and the elastic modulus of the composites increased with increasing AM content. The maximum strength reached 952±24 MPa and the highest elastic modulus about 156 GPa, respectively, in a longitudinal direction, increasing about 32% and 11% as compared with those of the composites without AM.
Co-reporter:Heng Zhang, Ping Shen, Alateng Shaga, Ruifen Guo, Qichuan Jiang
Materials Letters 2016 Volume 183() pp:299-302
Publication Date(Web):15 November 2016
DOI:10.1016/j.matlet.2016.07.126
•Bio-inspired lamellar AZ91/SiC composites were prepared using ice templating.•Preoxidation of SiC scaffolds greatly promoted the infiltration of Mg alloy.•Activation energy of spontaneous infiltration was estimated to be 7.74 kJ/mol.•The composite exhibited superior compressive and flexural strength to the Mg alloy.Lightweight and high-strength AZ91/SiC composites with lamellar structures were successfully prepared by using freeze casting (ice-templating) and reactive infiltration techniques. The infiltration dynamics was measured and activation energy calculated to be 7.74 kJ/mol. The compressive and flexural strengths of the composites with 30 vol% initial solid load reached 743±20 MPa and 599±44 MPa, about 1.8 and 1.5 times of those of the AZ91 alloy, respectively.
Co-reporter:Ping Shen, Yan Gu, Nan-Nan Yang, Rui-Peng Zheng, Li-Hua Ren
Applied Surface Science 2015 Volume 328() pp:380-386
Publication Date(Web):15 February 2015
DOI:10.1016/j.apsusc.2014.12.080
Highlights
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Applying DC improves the wettability of oxidized Fe by molten Sn.
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Applying DC greatly facilitates mass transfer and interfacial reaction (IR).
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Applying DC and IR have little effect on the wettability for clean Sn/Fe couples.
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Current polarity has a noticeable effect on interfacial microstructure.
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Unusual FeSn phase forms at the interface after wetting at 623 K under DC effect.
Co-reporter:Alateng Shaga, Ping Shen, Chang Sun, Qichuan Jiang
Materials Science and Engineering: A 2015 630() pp: 78-84
Publication Date(Web):
DOI:10.1016/j.msea.2015.02.012
Co-reporter:Lin-Yang Zhang, Ping Shen, Yan Qi, Qi-Chuan Jiang
Applied Surface Science 2013 Volume 276() pp:424-432
Publication Date(Web):1 July 2013
DOI:10.1016/j.apsusc.2013.03.110
Highlights
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Sn and Sn-base solders show good wettability with the Ni-base amorphous alloy.
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Mechanisms for the different wettability were discussed.
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Chemical reaction triggered the crystallization of the amorphous substrate.
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Sn-Bi, Sn-Pb and Sn-In solders were recommended for the joining of this glassy alloy.
Co-reporter:Ping Shen, Xiao-Hong Zheng, Hui-Jie Liu, Qi-Chuan Jiang
Materials Chemistry and Physics 2013 Volume 139(2–3) pp:646-653
Publication Date(Web):15 May 2013
DOI:10.1016/j.matchemphys.2013.02.012
Wetting of hot-pressed polycrystalline WC substrates by a Zr55Cu30Al10Ni5 bulk metallic glass (BMG)-forming alloy was investigated at 1133–1253 K in a high vacuum using a modified sessile drop method. The alloy melt spread rapidly on the WC surface, reaching no more than 30° within 3 s, and then slowly (at T < 1213 K) or even remained steady (at T ≥ 1213 K) in the subsequent isothermal dwelling stage. The final equilibrium contact angles were between 11° and 20°, slightly increasing with rising temperature and thus presenting an appreciably anomalous temperature-dependent behavior. The reaction between WC and the Zr-base melt was moderate, slightly enhancing with increasing temperature, and yielded W, ZrC and W5Zr3 at the interface. The wetting, in principle, was driven by the formation of a precursor film in front of the triple line as a result of the adsorption of active atoms (primarily Zr) rather than by the interfacial reaction. From the viewpoint of the wettability and reactivity, WC is a good reinforcement for the preparation of the Zr-base BMG matrix composites.Highlights► WC shows good wettability and moderate reactivity with the Zr55Cu30Al10Ni5 melt. ► The final wettability exhibits slightly anomalous dependence on temperature. ► The interfacial reaction yields ZrC, W and W5Zr3 phases. ► The primary driving force for the wetting is the formation of the precursor film in front of the triple line.
Co-reporter:Laixin Shi;Dan Zhang;Erting Dong
Journal of Materials Science 2012 Volume 47( Issue 24) pp:8372-8380
Publication Date(Web):2012 December
DOI:10.1007/s10853-012-6784-5
The wetting of (0001) α-alumina single crystals by Mg–Al alloys over a wide composition range at 1073 K was investigated using an improved sessile drop method in a flowing argon atmosphere. The initial contact angles are between 103° and 84°, almost linearly decreasing with increasing nominal Mg concentration, suggesting that the addition of Mg to Al improves the initial wettability. According to the evolution of contact angle and contact diameter, representative stages were identified to characterize the complex wetting behavior in the presence of evaporation. The wetting kinetics was dependent on the nominal Mg concentration in the alloy. Two patterns of “stick–slip” behavior were observed in the wetting process and interpreted by combining the effects of interfacial reaction and evaporation of magnesium. In addition, the dependence of the interfacial reaction on the Mg–Al alloy concentration was thermodynamically analyzed. The dominant reaction product at 1073 K should be MgO when xMg > 9 mol%, while MgAl2O4 when xMg < 9 mol%. However, because of the continuous consumption of Mg due to the evaporation and reaction, its concentration in the alloy progressively decreased with time. As a result, MgO formed usually earlier while MgAl2O4 later even for the alloys with higher than 9 mol% Mg.
Co-reporter:Qiaoli Lin, Ping Shen, Longlong Yang, Shenbao Jin, Qichuan Jiang
Acta Materialia 2011 Volume 59(Issue 5) pp:1898-1911
Publication Date(Web):March 2011
DOI:10.1016/j.actamat.2010.11.055
Abstract
The wetting of titanium carbide (TiC0.7) by liquid Al was studied using an improved sessile drop method at 1123–1323 K. The initial contact angles were 77–79°, almost independent of temperature, and the final equilibrium contact angles between 17° and 12°, slightly decreasing with increasing temperature. The interfacial reaction yielded Al4C3 and dissolved [Ti] in the early stage of the wetting, and then the formation of the Al4C3 phase was halted by excess Ti accumulated at the interface. As a result, the wetting is essentially improved initially by the formation of the Al4C3 phase and then by the adsorption of Ti at the solid–liquid interface. The role of the Ti adsorption was further demonstrated by the wetting of TiC0.7 by an Al–1 at.% Ti alloy.
Co-reporter:Laixin Shi, Ping Shen, Dan Zhang, Qichuan Jiang
Applied Surface Science 2011 Volume 257(Issue 24) pp:10743-10747
Publication Date(Web):1 October 2011
DOI:10.1016/j.apsusc.2011.07.090
Abstract
Wetting of (0 0 0 1) α-Al2O3 single crystal by molten Mg was studied by an improved sessile drop method in a purified flowing Ar atmosphere. A distinct pinning–depinning behavior was observed during the evaporation-coupled wetting process. The underlying mechanism for this behavior was expatiated from the viewpoints of energetics and geometries at the triple junction.
Co-reporter:Lai-Xin Shi, Ping Shen, Dan Zhang, Qi-Chuan Jiang
Materials Chemistry and Physics 2011 130(3) pp: 1125-1133
Publication Date(Web):
DOI:10.1016/j.matchemphys.2011.08.051
Co-reporter:Longlong Yang, Ping Shen, Qiaoli Lin, Feng Qiu, Qichuan Jiang
Materials Chemistry and Physics 2010 Volume 124(Issue 1) pp:499-503
Publication Date(Web):1 November 2010
DOI:10.1016/j.matchemphys.2010.07.001
The isotherm wetting of porous graphite substrates by the molten Cu–Ti alloys with 1, 3, 4 and 5 at.% Ti was investigated at 1373 K in a flowing Ar atmosphere using a modified sessile drop method. The wettability increases with increasing Ti content in the alloy and the equilibrium contact angle reaches 6° for the Cu–5 at.% Ti alloy. The improvement of the wettability is due to the formation of a substoichiometric TiCx reaction layer at the interface. Increasing the Ti content makes the resultant TiCx phase more substoichiometric and thus significantly promotes the wettability.
Co-reporter:Jun Yang, Ping Shen, Zhongfa Yin, Jianxin Sun, Qichuan Jiang
Materials Letters 2010 Volume 64(Issue 22) pp:2454-2457
Publication Date(Web):30 November 2010
DOI:10.1016/j.matlet.2010.08.017
Wetting behavior of molten Sn–3.5Ag–0.7Cu drops on Ni substrates with micrometer and nanometer grains was investigated using a modified sessile drop method. The wettability was poorer while the interfacial reactivity and atomic diffusivity were stronger for the nanocrystalline substrates compared with those for the microcrystalline substrates. The enhanced diffusion of the Ni atoms from the nanocrystallites greatly promoted the nucleation of the intermetallic compounds (IMCs), leading to a much thicker reaction layer and a more distinct regional distribution of the IMCs. On the other hand, the immediately roughened interface greatly decelerated the spreading of the triple line.
Co-reporter:Ping Shen, Dan Zhang, Qiaoli Lin, Laixin Shi, Qichuan Jiang
Materials Chemistry and Physics 2010 Volume 122(Issue 1) pp:290-294
Publication Date(Web):1 July 2010
DOI:10.1016/j.matchemphys.2010.02.052
The concomitant wetting and evaporation behaviors of molten Mg on polycrystalline MgO surfaces were studied at temperatures 973–1173 K in a controlled Ar atmosphere using an improved sessile drop method. Representative wetting modes were identified by correlating contact angle with contact diameter and drop height. The intrinsic wettability in this nonreactive system can be characterized by the initial contact angles obtained in better precision from solution to a diffusion model. In addition, the excess free energy stored in the system and the potential energy barrier opposing the movement of the triple line were evaluated to account for the distinct “stick-slip” behavior.
Co-reporter:Ping Shen;Dan Zhang;Qiao-Li Lin
Metallurgical and Materials Transactions A 2010 Volume 41( Issue 7) pp:1621-1626
Publication Date(Web):2010 July
DOI:10.1007/s11661-010-0224-4
The characteristic wetting behavior and modes of the evaporating Mg drops on the α-Al2O3 surfaces were evaluated by a combination of the variations in contact angle and drop geometry using both improved and modified sessile drop methods. The system is essentially partial wetting at 973 to 1173 K with initial contact angles of 94 to 67 deg, decreasing with increasing temperature. The wettability improves with interfacial reaction but deteriorates with Mg surface oxidation. The presence of the oxide film at the Mg drop surface strongly inhibits the movement of the triple line and thus makes the constant contact diameter mode dominate the entire wetting process. Removal of the oxide film greatly facilitates the depinning of the triple line. On the other hand, the interfacial reaction leads to the prior formation of MgO and later MgAl2O4 as a result of consumption of Mg, while it increases the amount of displaced Al. Nevertheless, the role of the interfacial reaction on the wetting is difficult to quantitatively evaluate because of concurrent diminishing in the drop volume under evaporation.
Co-reporter:Ping Shen, Hidetoshi Fujii, Kiyoshi Nogi
Materials Chemistry and Physics 2009 Volume 114(2–3) pp:681-686
Publication Date(Web):15 April 2009
DOI:10.1016/j.matchemphys.2008.10.021
The wettability of some refractory materials, including Mo, Pt, W, polycrystalline Al2O3, MgO, and graphite, by a molten 38.7 wt.% SiO2–44.3 wt.% MnO–11.4 wt.% TiO2–5.6 wt.% FeOx (x = 1 or 1.5) slag was investigated at temperatures between 1473 and 1673 K in an Ar atmosphere. The slag wets these materials quite well and the work of adhesion is in the range of 0.60–0.75 J m−2, except for graphite. A strong reaction between the slag and Al2O3 as well as MgO leads to small apparent contact angles (∼10 ± 2°) and good adherence. The wettability of the refractory metals depends not only on temperature but also on metal species. At 1473 K, the wettability is in the order of Pt > W > Mo. An increase in temperature considerably promotes the wettability of Mo and W while only mildly for Pt. The wettability and adhesion of graphite by the slag is poor. However, a temperature-dependent reaction leads to a considerable decrease in the contact angle as well as a foaming behavior of the sessile drop.
Co-reporter:Xiaohong Zheng, Ping Shen, Xianhe Han, Qiaoli Lin, Feng Qiu, Yefei Zhang, Qichuan Jiang
Materials Chemistry and Physics 2009 Volume 117(2–3) pp:377-383
Publication Date(Web):15 October 2009
DOI:10.1016/j.matchemphys.2009.06.017
The isothermal wetting and spreading behaviors of molten Zr55Cu30Al10Ni5 metallic glass alloy on B4C substrates were studied using a modified sessile drop method at 1133–1253 K in a high vacuum. A distinct reaction layer consisting of ZrB2 and ZrCx was produced at the interface and displayed good wettability with the molten alloy. The entire spreading kinetics could be characterized by four representative stages: (i) an initial rapid spreading presumably driven by adsorption of the active Zr atoms at the solid–liquid interface, (ii) a quasi-linear and (iii) a linear spreading stage controlled by the chemical reaction between Zr and B4C in both cases, and (iv) an approach-to-equilibrium stage with precipitation of crystals in the liquid. An increase in temperature promotes the wetting and reaction. In view of the reasonable wettability and reactivity, there is a potential for preparing Zr-base bulk metallic glass matrix composites reinforced by in situ ZrC–ZrB2 hybrid ceramic particulates using B4C as a reaction agent by way of an infiltration synthesis technique.
Co-reporter:Ping Shen, Dan Zhang, Xiaohong Zheng, Qiaoli Lin, Qichuan Jiang
Materials Chemistry and Physics 2009 Volume 115(Issue 1) pp:322-327
Publication Date(Web):15 May 2009
DOI:10.1016/j.matchemphys.2008.12.025
Wetting of polycrystalline W substrates by a molten Zr55Al10Ni5Cu30 alloy was studied using a modified sessile drop method at 1123–1173 K in high vacuum. Good wettability with final stable contact angles of 4–11° was observed. The Zr adsorption at the solid–liquid interface and further diffusion to the front of the triple line should be the primary reason for the enhanced wettability and the formation of a diffusion band. Moreover, the interfacial microstructure is dictated by temperature. A higher temperature substantially promotes the dissolution of W into the liquid alloy and then precipitation of the W2Zr phase. Accordingly, the processing temperature should be accurately controlled in preparation of the Zr-base bulk metallic glass (BMG) matrix composites reinforced by W particulates or fibers.
Co-reporter:Rui-Fen Guo, Hao-Chen Lv, Ping Shen, Zhi-Jie Hu, Qi-Chuan Jiang
Ceramics International (15 February 2017) Volume 43(Issue 3) pp:
Publication Date(Web):15 February 2017
DOI:10.1016/j.ceramint.2016.11.162
Using freeze casting and pressureless infiltration methods, we prepared lamellar Al−Si−Mg/Al2O3−ZrO2 composites with initial ceramic loading of 30 vol% and different Al2O3:ZrO2 weight ratios (Al2O3:ZrO2=1:9, 3:7, 5:5, 7:3 and 9:1). The resultant composites inherited the lamellar structure of the Al2O3−ZrO2 scaffolds, and the thickness of both metal and ceramic layers showed a trend of first increase and then decrease with increasing Al2O3 content. During pressureless infiltration, multiple chemical reactions took place between ZrO2 and the Al−12Si−10Mg alloy and the main reaction products were (Al1−m, Sim)3Zr, Al2O3 and ZrSi2 phases. The degree of the reaction depended on the ZrO2 content in the ceramic composition. In general, the compressive strength of the composites decreased with increasing Al2O3 content, but three-point bending strength showed a first decrease and then increase. When Al2O3:ZrO2=1:9, the compressive and bending strength of the composites reached about 997±60 MPa and 426±10 MPa, respectively. A simple model was proposed to illustrate the fracture mode and toughening mechanism of the composites.
