Study on chemical corrosion properties of titanium alloy in 2A14 aluminum melt

Abstract

Titanium alloy radiation rods have excellent physical and chemical properties compared to other materials, and are commonly used for ultrasonic casting of 2A14 aluminum alloy. However, titanium alloys are chemically corroded in high-temperature aluminum melts for a long time, making it difficult to precisely regulate the elemental composition during casting. In order to better understand the high-temperature chemical corrosion mechanism of titanium alloy radiation rods, this research looks into the corrosion morphology, weight loss, surface roughness, and reaction layer. The study’s findings suggest that the rate of chemical corrosion of titanium alloy in high-temperature aluminum melt is often inversely correlated with the degree of roughness, with the degree of roughness changing nonlinearly during the corrosion process. Titanium alloy weight loss rates with roughness Ra0.4 μm, Ra7.2 μm, Ra9.5 μm and Ra9.8 μm are 0.16 mg per min, 0.25 mg per min, 0.37 mg per min and 0.29 mg per min, respectively. The corrosion product of the chemical corrosion process is TiAl3, which is granular. Under varying roughness conditions, the solid-liquid interface of Al/Ti emerges reactants after 4 min, and the TiAl3 reaction layer arises after 12 min. Furthermore, the reaction layer with little roughness is flat and compact, whereas the reaction layer with great roughness is loose and contains many faults. At the same time, the growth rate of the reaction layer decreases slightly. And the greater the surface roughness, the greater the TiAl3 reaction layer grows at the titanium alloy matrix.