Papers by Author: Xiao Ming Wang

Abstract: In this study, the anti-corrosion properties of nickel-based coatings on the surface of copper alloy were investigated, and damages caused by corrosion on the copper surface were resolved. Researchers prepared nickel-based coatings by supersonic particles deposition, and tested the anti-corrosion properties of brass substrate and nickel-based coating by electrochemical technology and neutral salt spray. The results show that, the corrosion current of coating decreased 35 times than that of matrix. The successive and pyknotic oxide film on the surface of coating prevented reaction of corrosion further. When it reached 500 hours, the corrosion rate closed to 0. Nickel-based coatings prepared by supersonic particles deposition contribute to the increase of corrosion resistance significantly, which verifies that it is feasible to prepare outstanding corrosion resisting nickel-based coating by supersonic particles deposition.

Abstract: This article briefly describes the main characteristics of a certain type of engine fuel control system, deeply researches the alternate control of electronics and mechanical hydraulic actuator in the throttle and the largest state of the high-pressure speed regulation aiming at the speed control system malfunction,and avoid the such failure of the engine.

Abstract: In this study, Gamma TiAl intermetallic alloy protective coating was deposited on the surface of 5803 aluminum alloy by supersonic particles deposition. Researchers observed the surface morphology of the coating by SEM, and researched tribological properties of the substrate material and the coating by CETR friction and wear tester and Talysurf 5P-120 surface morphology tester. The results show that,the bonding mechanism of the Gamma TiAl intermetallic alloy coating and substrate is mechanical interlocking and metallurgical bonding. The abrasion mechanism of Gamma TiAl intermetallic alloy coating is abrasive Wear. The friction coefficients of the coating are all lower than 5083 alumium alloy. The friction volume of coatings reduced 36.7% than 5083 aluminum alloy with the friction loads 50N. TiAl coating has great function to anti-attrition and wearability.

Abstract: 7A52 aluminum alloy was welded by using 5356 welding wire added Sc, Zr and Er. Microstructure of the welding joint was observed by using optical microscope (OM). Bending property was tested by bending tester. The results demonstrated that, compared to employ traditional 5356 welding wire, the grains in welding zone (WZ) were much finer; The grains in fused zone (FZ) nucleated and grew from the matrix; The grain size along heat affected zone (HAZ) dercearsed gradually.The welding joint prepared by using 5356 welding wire added single 0.3%Sc possessed maxium face bending strength. The welding joint fabricated by using 5356 welding wire added compond 0.1%Sc+0.2% Er possessed maxium rear bending strength. The fine isometric crystal and isometric dendrite generated at the welding zone when the new type 5356 wire added gingle Sc or compound Sc+Er was employed, which make the welding joint represent excellent bending property, respectively.

Abstract: Numerical simulation of sequential collision behavior of multi-particles during dynamic formation of Al-based coating on magnesium alloy by supersonic particles deposition demonstrated that continuous tamping effect from subsequent sprayed particles improved significantly compression ratio of former deposited particle and promote effectively deformation and spread out. Analysis to morphology and microstructure of Al-based coating on magnesium alloy by SEM and TEM elicited that subsequent sprayed particles generated two effects including erosion and compaction to former deposited layer of the coating, induced formation of high density dislocation, grains refinement and re-crystallization, which played work-hardening strengthening effect and fine crystal strengthening effect to Al-Si coating.

Abstract: High entropy alloys emerge as a new type of advanced metallic materials, which have received increasing attentions from material engineers around the world. In addition to high entropy effect based on equiatomic or near-equiatomic and containing five or more principal elements, they exhibit a cocktail effect resulting from interactions among all the elements and the indirect effects of the various elements on the performances. In this study, according to high entropy alloy design principles, corrosion-resistant elements such as Al, Ni, Cr and Mo were used to improve the anticorrosion property, Fe, Co, B and Si as solid solution elements were added to promote the formation of solid solutions with simple structure, and the wear-resisting property increased.

Abstract: Al-based coating on ZM5 magnesium alloy was prepared by Supersonic Particles Deposition (SPD). Electrochemical working station was utilized to test polarization curve, corrosion potential and electrochemical impedance spectroscopy etc. The results indicted that corrosion potential of Al-Si coating was about-767.6mV, much higher than that of ZM5 Mg-substrate; And corrosion current density of the coating sample decreased three order of magnitude than that of the uncoated. Compared to Mg-substrate, the radius of capacitive impedance arc of the coating enlarged and impedance modulus improved two order of magnitude.

Abstract: Deposition behavior of Al-Si particles coated on magnesium alloy by Supersonic Particles Deposition (SPD) was investigated by numerical stimulation. The results demonstrated that critical velocity for Al-Si particle to deposit successfully on ZM5 magnesium alloy was about 700m/s; At collision interface, the temperature gradient increased, effective plastic strain change suddenly and stress reduce rapidly to zero. The compression ratio of deposited particles increased. Contacting area at interface enlarged with particle initial velocity increasing. Meanwhile, experimental observation of surface and cross-section morphology of Al-Si coating on magnesium alloy exhibited that, intact particles, fragmented particles and fine particles co-existed in the coating. And the coating was formed by mechanical bonding and metallurgical bonding.

Abstract: High entropy alloys are new alloys composed of over five principal elements with each having an atomic percentage in the range of 5%~35%, which break through the concept of traditional alloys design. In this paper, AlxFeCoNiCr (B) high entropy alloys were prepared in an vacuum arc induction melting furnace. The microstructure presents simple solid solution structure, and the fraction of FCC crystal structure decreased with increasing of Al content. Chromium tends to segregate at the inter-dendrite grain boundary. Electrochemical investigations indicated that AlxFeCoNiCr (B) high entropy alloys were more corrosion resistance than 316L stainless steel.

Abstract: In order to protect magnesium alloy structure used in equipments, Al-based alloy coating on ZM5 magnesium alloy surface was prepared by Supersonic-Particles-Deposition(SPD). Microstructure,bonding strength,hardness, anti-scratch property of the deposited Al-based alloy coating were analyzed and tested using scanning electron microscope(SEM),energy dispersive spectrmomter(EDS), dualization stretching method and scratch testing machine. The results indicated that the coating was compacted with 1.19% porosity on superficial layer and 0.08% porosity on cross-section, respectively. The bonding strength value was 42.37MPa, moreover the interface was distinct and continuous,without defects such as ablation and impurity. Microhardness of the coating was about 1.3 times to that of uncoated substrate. The anti-scratch property of the processed coating improved obviously compared to Mg-substrate.