Effect of SiC Content on Hot Corrosion Resistance of TiC and Ti 5 Si 3 Reinforced Ti-Al-Sn-Zr Titanium Matrix Composites

TiC and Ti5Si3 reinforced titanium matrix composites (TMCs) were successfully prepared by an in situ reaction of SiC particles with Ti-Al-Sn-Zr alloy through powder metallurgy. By studying the microstructure and phase composition after corrosion at 750 and 850 °C for 30 h in a corrosive environment of 25% NaCl + 75% Na2SO4, the resistance to hot corrosion of composite materials with different contents of SiC particles was valuated. The results showed that at 750 °C, the corrosion depth (18 μm) of the TMCs with 10 vol.% SiCp was 75% less than that of the matrix. After the samples corrosion for 30 h at 750 and 850 °C, the maximum corrosion gain of the TMCs with 10 vol.% SiCp was 6.16 and 30.57 mg cm−2, respectively. The maximum corrosion mass gain decreased by 60.03 and 35.49% compared with the matrix at 750 °C (15.41 mg cm−2) and 850 °C (47.39 mg cm−2). In addition, the XRD result showed that corrosion products of three composites are similar at 750 and 850 °C, and mainly composed of TiO2, SiO2, Al2O3, NaTiO2, Na2Si2O5 and TiS2. The TMCs with 10 vol.% SiCp had more SiO2. All the data showed that SiCp was beneficial to the hot corrosion properties of the samples, and as the content of SiCp increased, the corrosion resistance was better.