Effect of Hot Stamping Pressure on the Microstructure, Corrosion Resistance, and Wear Resistance of Selective Laser Melting Fabricated Ti6Al4V
摘要
This study investigates the effect of hot stamping pressure (10, 50, and 100 MPa) on the microstructure, corrosion resistance, and wear behavior of selective laser melting (SLM) fabricated Ti6Al4V alloy. The results showed as the pressure increases, the grain size expands from 2.56 to 4.46 μm, accompanied by the transformation of acicular α′-phase into lamellar α-phase and a fluctuation in β-phase content. These changes indicate that higher pressure promotes dynamic recrystallization and enhances phase stability. Electrochemical results reveal that the corrosion current density decreases significantly at 50 MPa (23.43 nA/cm2) compared to 10 MPa (48.65 nA/cm2) and 100 MPa (70.66 nA/cm2), suggesting an optimal corrosion resistance. This improvement is attributed to the highest recrystallization degree (76.3%) and thickest passive film (0.64 nm), which enhance film compactness and stability. In contrast, the wear rate reaches its lowest value at 100 MPa (3.29 × 10−5 mm3/(N·m)) due to the formation of a stable oxide layer and optimized grain boundaries, reducing adhesive wear. In general, the SLM-fabricated Ti6Al4V alloy achieves optimal corrosion resistance under a hot stamping pressure of 50 MPa, and optimal wear resistance at 100 MPa.