Mechanical Behaviour of Maraging Steel Produced by SLM

Abstract

Metallic additive manufacturing has been developed as a manufacturing process for complex functional parts that may be potentially applied in various engineering fields, with very distinct mechanical performance requisites. Therefore, it is of primary importance to characterize additive manufacturing materials under various loading conditions in other to understand possible distinctive behaviours as regards the conventional material counterparts. This paper aims at characterizing the mechanical behaviour of a very common material for additive manufacturing applications – the 18Ni300 maraging steel. A set of physical and mechanical tests were performed on conventional and additive maraging steel. Regarding the physical properties, the heat capacity and conductivity were measured with temperature; regarding mechanical characterization, compression tests were performed at various (high) strain rates. Also, tensile tests were performed covering distinct stress triaxialities. Finally, multiaxial tests were performed to evaluate the quasi-static mechanical response of the materials under combined tension/compression and shear loadings with the assistance of Digital Image Correlation. Inverse numerical analyses were performed to evaluate the best constitutive modelling strategies for the materials. Tests revealed the very complex behaviour of the maraging steels and the additive material showed higher strength than the conventional material.