Shielding effects on fatigue and crack growth of the recasting zone induced by laser manufacturing in a nickel-based superalloy

Abstract

In the present work, the fatigue property and crack growth of the laser recasting material were experimentally and computationally investigated. Based on the mechanical properties identified by instrumented indentation, detailed finite element computations were performed within cyclic plasticity. The shielding effect is attributed to strength mismatch, leading to cyclic softening and mean stress relaxation in the under-matched recasting material. The recasting material shows a higher crack nucleation resistance and a lower crack growth rate than base material due to the shielding effect. The result confirms that the weak recasting zone cannot diminish the overall mechanical performance of structure.