The Japanese Institute of Industrial Technology (AIST) has developed a low reaction sand mold, which is expected to achieve low-cost sand mold casting of titanium alloy. The sand mold is made of low-cost materials and has little reaction with the titanium alloy melt surface with high melting point and high activity. Moreover, titanium alloy casting can be carried out without preheating, so the melt solidification speed is high and the casting has dense metallographic structure.
The surface hardness of the ti-6Al-4V alloy casting was almost the same as that of the initial Ti-6Al-4V alloy, and the formation of the surface reaction layer was not observed. The casting also had good metallic luster. The strength of Ti-6Al-4V alloy sand casting exceeds the standard strength value of casting material and plastic processed material (bar) stipulated in ASTM standard, especially the elongation at break is about 2 times and 1.3 times of the standard value of casting material and plastic material respectively. The casting test of large titanium alloy parts will be carried out in the future to promote the application of sand casting technology in large titanium alloy parts.
