Papers by Author: Wei Ye Chen

Abstract: Ti-6Al-4V alloy ribbons were successfully prepared by rapid solidification at different roller speeds. The morphology and microstructure of Ti-6Al-4V alloy ribbons were studied by X-ray diffractometer, scanning electron microscope and energy spectrum analysis. The effect of SiO₂ on the microstructure and properties of Ti-6Al-4V alloy ribbons were discussed. It is found that the Ti-6Al-4V alloy ribbons consist of β phase with alternated distribution of α' phase and α'' phase. And quicker roller speed promotes the formation of α' phase for the higher rapid solidificationg cooling rate. According to the analysis of energy spectrum data, it is found that there is chemical reactions between the Ti-6Al-4V material and the quartz tube wall during electromagnetic induction melting at high temperature, and the Si elements are segregated at the embossment induced by quick solidification and the phase interfaces between α′ phase and β phase.

Abstract: Grain refinement can greatly enhance the material mechanics, magnetism and other physical properties. Exploration of grain refinement methodology has been one of the hottest fields of material research. Among all the methods, deep supercooling technology is an effective way to refine the grains. In this paper, the grain refinement mechanism has been explored by deep supercooling and rapid solidification technique with introducing grain refined process of pure metal, binary uniform crystalline alloy and the binary eutectic alloy. Furthermore, peritectic grain refinement mechanism and rapid solidification technique have been discussed.

Abstract: The history of aluminium-lithium alloys development has been reviewed in this paper. According to the strength, weld ability and corrosion resistance, thermal stability and plasticity, aluminium-lithium alloy has been categorized and the defects of aluminium-lithium alloys in early stage have been analyzed. As compared the third generation of aluminium-lithium alloy with normal aluminum alloy and composite materials, it indicates aluminium-lithium alloy has better performance, lower cost and reduced weight. After analyzing the advantages and disadvantages of the rapid solidification, ingot casting metallurgy and electromagnetic simulated microgravity methods in synthesis of aluminium-lithium alloy, it has been found microgravity method has prominent effect on reducing the alloy segregation and lithium losses. Finally, the future development of aluminium-lithium alloys has been discussed.

Abstract: The texture evolution of the pure iron sample after the surface mechanical attrition treatment (SMAT) was investigated by means of electron backscattering and X-ray diffraction (XRD) analysis. Experimental observations indicated that four sections along depth were formed in the pure iron sample during the SMAT, i.e., nanostructured regime in the surface layer, submicro-sized, micro-sized and plastic deformed regime. Compared to the microstructure of sample, texture analysis was performed. It can be found that the <110>//ND fiber texture is the prominent texture. A strong orientation of (110)[11] along the <110>//ND fiber was formed in the plastic deformed regime, and as the depth from the top surface decreases, <110> //ND fiber texture intensity increases. The maximum intensity was reached in the micro-sized regime, and then it start to reduce. In the nanostructured regime, <110> //ND fiber texture nearly disappear.

Abstract: The texture evolution in the plastic deformation layer of the pure iron sample after the surface mechanical attrition treatment (SMAT) was discussed through electron backscattering and X-ray diffraction (XRD) analysis. The results showed that: the surface layer of the iron sample can be subdivided into four sub-layers along the depth from the top surface: nano-sized regime, submicro-sized regime, micro-sized regime and deformed coarse-grained regime. Nano-sized regime possesses random crystallographic orientations. But in submicro-sized regime and micro-sized regime, the //ND fiber texture is the prominent texture with a strong orientation of (110)[1-11]. Increasing treatment time during SMAT process does not change the components of texture in plastic deformation layer, only strengthen their orientation density.