Study on fatigue damage evolution behavior of SLM formed IN 718 alloy

Abstract

SLM (Selective Laser Melting) Inconel718 alloy has good corrosion resistance, oxidation resistance and fatigue resistance, which is an indispensable and important material in industrial fields such as energy power, aerospace and nuclear power. In this paper, the fatigue damage evolution behavior of SLM Inconel718 alloy under different heat treatment is studied by the MTS fatigue testing machine and DIC (digital image correlation method). The results show that the fatigue evolution of SLM Inconel718 alloy changes slowly in the initial stage of fatigue evolution. When the damage factor reaches the critical value, alloy begins to enter the rapid damage stage. In the steady stage, SLM Inconel718 alloy has small damage accumulation. In the rapid damage stage, the damage degree of SLM Inconel718 alloy increases and the damage accumulates rapidly. The critical damage factor can effectively distinguish these two stages, and the critical damage factor under different heat treatment shows: AT2 > AT1 > AT3.