Papers by Author: Li Wen Tang

Abstract: Corrosion properties of magnesium alloys coupled with foreign metals impose much influence on the life of the parts. In this paper, the corrosion properties of AZ31 magnesium alloy coupled with nitrided 40Cr steel were investigated through immersion test in saline solution and weight loss test combining with optical microscope (OM) and scanning electronic microscope (SEM) analysis. The results indicate that the anticorrosion properties of the AZ31 magnesium alloy coupled with nitrided 40Cr steel are higher than those of the AZ31 magnesium alloy coupled with unnitrided 40Cr steel. The mechanism is attributed to the resultant nitrided layer which reduces the conductive properties.

Abstract: In the paper the microstructure and properties of surface coating for Cr12MoV steel treated by TD (Thermal Diffusion) salt-bath vanadizing process are investigated. The research results indicate that after treated by the TD salt-bath vanadizing at 1223K for 5h and followed by oil quenching, and aged at 453K for 2h, the Cr12MoV steel could obtain a surface coating whose thickness is about 11.4um. The coating is mainly composed of vanadium carbide, and its thickness and microstructure are uniform and compact, respectively. At the same time, the coating obtained exhibits super-high surface microhardness, 2586HV. Then the wear resistance property of Cr12MoV steel is improved drastically. In addition, the research results reveal that the effect of TD salt-bath vanadizing treatment on the surface roughness of Cr12MoV steel is not obvious.

Abstract: In this paper, the effects of Sb and RE on the solutionized microstructure and microhardness of Mg-6A1-1Zn-0.7Si magnesium alloy are investigated. The research results indicate that the solid solution treatment can result to the modification of Chinese script shaped Mg2Si phases in the microstructure of experimental alloy, and adding small amounts of RE and Sb can strengthen the modification efficiency. In addition, after the solid solution treatment at 420°C, the Mg-6A1-1Zn-0.7Si alloy added 0.4%Sb and 0.25%RE exhibits higher microhardness, but the effect of Sb and RE additions on the changing law between microhardness and solutionized time, is not obvious.

Abstract: The semi-solid compression deformation behavior of the AZ91D alloy with non-dendritic structure, which was obtained under the semi-solid isothermal treatment condition of 570°C×60min, was studied by means of Gleeble-1500 thermal-mechanical simulator. When the compression strain was lower than 0.7, along with the compression strain increasing, the compression stress firstly increased rapidly, then decreased rapidly, and finally kept a constant stress level gradually. Under the condition of different deformation temperatures and deformation rates, the maximum compression stress was obtained simultaneously when the compression strain value was 0.025 approximatively. Furthermore, when the deformation rate kept a constant, the compression stress decreased along with the deformation temperature increasing, and when the deformation temperature kept a constant, the compression stress increased along with the deformation rate increasing.