Fast fatigue characterization by infrared thermography for additive manufacturing

Abstract

High cooling rates and strong temperature gradients occurring during additive manufacturing (AM) by laser beam melting (LBM) are known to affect mechanical performances of the produced parts, and particularly fatigue properties. Mechanical properties strongly depend on the process parameters such as laser power, scan speed and laser spot size. A fatigue analysis was performed in this study by using infrared thermography to assess heat sources associated with fatigue damage. In particular, mechanical dissipation was identified thanks to suitable acquisition parameters. A model for the relationship between mechanical dissipation and mechanical solicitation was proposed and applied to two promising steels in LBM AM field, namely maraging 18Ni300 and L40 tool steel.