Lv Xuewei

Preparation and Compressive Properties of Magnesium Foam

Abstract As a new structural and functional material, metal foam has been proven to obtain excellent properties when compared with dense ones. In the present paper, the powder metallurgy with a space holder technique was used to prepare magnesium foam. The porosity of the foam ranges from 38.90% to 57.50%, when the elastic modulus decreases from 8.50 GPa to 3.30 GPa, and the initial yield stress decreases from 24.90 MPa to 9.40 MPa. The magnesium foam has lower yield stress and longer stress platform, so it can be used as good cushioning energy absorbing materials.

Surface Tension of Liquid Ti-Al Alloys

Abstract The surface tension of liquid Ti-Al alloys at 1758 K was determined by an improved sessile drop method. The surface tension of liquid Ti-Al alloys was calculated using the Butlers model and several modified ideal solution models. Results show that the surface tension of liquid Ti-Al alloy decreases with increased Al concentration. Experimental results agree well with both the Butlers model and the modified ideal solution model. The segregation of Al atoms to the surface occurs at all bulk concentrations of Ti-Al alloys. Al with lower surface tension prefers to segregate on the surface of liquid Ti-Al alloy, whereas Ti with higher surface tension prefers to segregate inside the molten alloy. The effect of surface active solute on the surface tension of liquid Ti-Al alloy was also discussed. Sulfur is found to have a larger effect on the surface tension of alloy. The surface tension of liquid Ti-Al alloy decreases with increased sulfur concentration. Sulfur concentration on the surface is higher than that in the bulk. Thus, the adsorption of sulfur for Ti-Al alloys is a positive adsorption.

Effect of Electrical Conductivity and Porosity of Cathode on Electro-Deoxidation Process of Ilmenite Concentrate

Abstract The performance of the cathode is always closely related to the electro-deoxidation process and its current efficiency. In this work, the effect of sintering temperature on the electrical resistivity of an ilmenite concentrate cathode was measured. The results show that the sintering temperature has a significant effect on the electrical conductivity of the cathode. The electrical resistivity of the ilmenite concentrate cathode decreases with increasing of the sintering temperature and increasing of the contact area. Besides, the influence of the cathode porosity on electrochemical process during preparation of Ti-Fe alloy in molten salt was studied. The results also reveal that the porosity of ilmenite concentrate cathode directly affects the electro-deoxidation process. The increasing of porosity is beneficial to the formation of intermediate product (CaTiO3) and improvement of the current efficiency.