Capability of Multi-Material Laser-Based Powder Bed Fusion—Development and Analysis of a Prototype Large Bore Engine Component

Abstract

Additive Manufacturing (AM) allows the manufacturing of functionally graded materials (FGM). This includes compositional grading, which enables the allocation of desired materials corresponding to local product requirements. An upcoming AM process for the creation of metal-based FGMs is laser-based powder bed fusion (PBF-LB/M) utilized for multi-material manufacturing (MM). Three-dimensional multi-material approaches for PBF-LB/M are stated to have a manufacturing readiness level (MRL) of 4 to 5. In this paper, an advancement of multi-material technology is presented by realizing an industry-relevant complex part as a prototype made by PBF-LB/M. Hence, a multi-material injection nozzle consisting of tool steel and a copper alloy was manufactured in a continuous PBF-LB/M process. Single material regions showed qualities similar to the ones resulting from mono-material processes. A geometrically defined transition zone between the two materials was achieved that showed slightly higher porosity than mono-material regions. Nevertheless, defects such as porosity, cracks, and material cross-contamination were detected and must be overcome in further MM technology development.