An Experimental Study on the Fatigue Response of Hybrid Additively Manufactured 1.2343 Hot Work Steel - MARAGING Steel MS1

Abstract

Hybrid additive manufacturing consists of upgrading wrought material by an additive process, adding stacked layers through the melting and sintering of a different material powder. A literature survey indicates that fatigue data for hybrid additively manufactured parts are currently missing. This paper is focused on the fatigue response of 1.2343 hot work steel, upgraded by a maraging steel MS1 powder processed by laser powder bed fusion, and finally heat-treated complying with the specifications from the powder supplier. Results, supported by microscopy SEM analyses, indicate the fatigue response is significantly reduced if compared to that of plain additively manufactured MS1. This is due to the joint between the two materials acting as a weak point, where the porosity of MS1 is incremented with respect to specifications. Moreover, due to the unavailability of a heat treatment that is suitable for both the involved materials, the hot work steel side exhibits poor hardness.