Effect of Solution Treatment on Mechanical Properties of Inconel 625 Fabricated by Pulsed Micro-arc Plasma Additive Manufacturing

In order to improve the mechanical properties of Inconel 625 alloy thin-walled members fabricated by pulsed micro-arc plasma additive manufacturing, the members were solution treated at 950, 1050, 1150 and 1250 °C. The results show that with the increase of solution temperature, the degree of grain recrystallization increases and the growth orientation becomes disordered. The dislocation density decreases gradually and the distribution position is concentrated in the grain boundary region. The precipitates decrease gradually, showing a re-dissolution phenomenon. With the increase of temperature, the solution strengthening inside the structure improves the tensile strength, but the weakening of strain strengthening leads to the decrease of yield strength. At the same time, the blocking effect of Laves relative dislocation slip is weakened, and the elongation of thin-walled members is improved. The yield strength, tensile strength and elongation reach the comprehensively optimum after solution treatment at 1150 °C. This provides technical support for the performance optimization of Inconel 625 thin-walled components manufactured by micro-arc plasma additive manufacturing. © 2022 Rare Metals Materials and Engineering Press. All rights reserved.