Investigation on Tribological and Electrochemical Corrosion Properties of TiAl4822 Alloy Fabricated via Selective Laser Melting

TiAl alloy exhibits excellent strength, oxidation resistance and creep resistance, making it a preferred candidate material to replace high-temperature alloys. Currently, TiAl alloy has been widely applied in aerospace, the marine industry and other fields involving high-stress contact or highly corrosive environments. Selective laser melting (SLM) technology provides a brand-new approach for the fabrication of TiAl alloys, which enables direct forming of workpieces with complex structures and significantly reduces manufacturing cycles. However, the quality and performance of SLM fabricated TiAl alloys are highly dependent on laser energy input. Therefore, this study fabricated TiAl4822 alloy under different SLM process parameters, and systematically conducted investigations on its tribological properties and electrochemical corrosion behavior. The experimental results show that the SLM process did not alter the basic phase composition of TiAl4822 alloy, with Ti0.6Al0.4 as the dominant phase. TiAl4822 alloys fabricated under the parameter combinations of 1000 mm/s + 140 W exhibited outstanding wear resistance, and the wear mechanism transformed from severe adhesion and abrasive wear to mild oxidative wear. When the laser power was 100 W and the scanning speed was 1200 mm/s, the alloy achieved the highest corrosion resistance, with the corrosion potential reaching the maximum value of −390.065 mV and the corrosion current density decreasing to the minimum value of 8.73 × 10−6 A/cm2. Thus, different parameter combinations can realize the optimization of tribological properties and electrochemical corrosion performance respectively. This study lays a theoretical foundation for promoting the high-performance engineering application of this alloy in harsh wear-resistant and corrosion-resistant environments.