The diluent NaCl was introduced into the WO3-Mg-C-Na2CO3 system to prepare submicron tungsten carbide (WC) powders via salt-assisted combustion synthesis. The products were analyzed by SEM, EDS and XRD, and the effects of C content on morphology, average particle size and phase composition of the products were studied. Results show that on basis of the m = 0.125 (the number of moles of Na2CO3), when the number of moles of carbon in raw material increases from l =2 to 2.25 and 2.5, before leaching, the product is made up of a small number of large size particles and a large number of small size particles; after leaching, samples are composed of aggregates of submicron particles, and the sintering phenomenon between particles is very weak, indicating low degree of aggregation. Particle size distribution of leached product almost falls into the normal distribution, and the particle sizes range from 200 nm to 350 nm. Under the condition of l=2.25, a main target product is WC, and the content of by-products W2C is extremely few. That is, k = 2.0 (the number of moles of NaCl), m = 0.125, and l =2.25 are the process conditions for single-phase WC synthesis.

Bulk 1020 carbon steel was prepared by aluminothermic reaction casting. After casting, isothermal aging treatments at different temperatures are performed for different periods up to 8 h. Microstructure characterization was performed using many methods, including optical microscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. It was found that the steel consisted of a nanocrystalline- ferrite matrix and a microcrystalline pearlite phase with a laminar structure. The average grain sizes of the ferrite were 23, 24, 28, and 37 nm for the cast steel and for samples annealed at 600, 800, and 1000 °C, respectively. As the annealing temperature increased, the volume fraction of the pearlite initially increased and then decreased, while the laminar spacing of pearlite increased from 240 to 900 nm. When annealed at 1000 °C, a spherical black micron pearlite particle was formed. The tensile and yield strength dramatically decreased, and the elongation varied slightly with the annealing temperature. A ductile phase was achieved by extending the holding time.

Superwetting materials have attracted considerable interest both in academia and industry. In this work, the reduced graphene oxide (RGO)-coated cotton (GCC) was prepared by a facile and inexpensive dip-coating method. By modification with polydimethylsiloxane (PDMS), superhydrophobic and superoleophilic GCC was obtained, which shows a water contact angle of 152°. The PDMS-treated GCC exhibits selective absorption of organics and oils from water with an absorption capacity up to 11 to 25 times its weight. Also, the as-prepared product shows excellent stability and recyclability; both saturated absorption capacity and water CA value remain nearly unchanged after 9 cycles of use. Taking advantage of the excellent absorption selectivity, simple fabrication process, good stability and recyclability, this material may find a variety of applications such as in water treatment, purification, separation, oil spill cleanups and so on.

Microstructure and mechanical properties of large dimension bulk nanocrystalline Fe–Al–Cr alloy after being annealed at 1073 K for 16 h and at 1273 K for 8 h, 16 h, and 24 h were investigated. It was shown that microstructure of the alloy after the annealing consisted of a nanocrystalline phase with a small amount of micron-sized Cr7C3 phase. The crystal structure of the alloy did not change and still kept the disorder bcc structure after annealing. With the increase of annealing temperature and time, average grain size of the nanocrystalline phase increased, and shape of the Cr7C3 phase transformed from needles to particles. The alloy after annealing had more stable deformation capacity and high strength in the compression at room temperature, and yield strength of the alloy after annealing was about triple the time of the Fe3Al based alloy with microcrystalline structure. The strength of alloy decreased after annealing at 1273 K for 24 h.

The effects of process parameters-such as temperature evolution, cooling rate, and duration of overheating of Fe-Al-Cr melt-on the aluminothemic preparation of bulk nanocrystalline Fe-Al-Cr alloy were explored by using finite element analysis software ANSYS. The results show that the changes in temperature and cooling rate of the melt are evidently in the direction of height, while it remains nearly unchanged in the radial direction. The cooling rate of the Fe-Al-Cr melt increases slightly with increasing substrate thickness. The cooling rate of melt is significantly lower for glass substrate than that of 1045 steel and Cu substrate. Duration of overheating of the melt on glass is much larger than that on steel or copper substrate.