Novel approach of alloy design and selection for additive manufacturing towards targeted applications

Abstract

Powder bed fusion (PBF) is an additive manufacturing (AM) process, which allows manufacturing of components that have been traditionally fabricated as a subassembly using formative and subtractive processes. This reduction of parts can aid to fast-track qualification programs. The PBF process is akin to welding since individual tracks are build-up near and on top of one another. It is therefore expected that alloys for PBF exhibit good weldability (or printability), which is a compound attribute of an alloy’s response to given processing conditions. However, numerous industrial relevant alloys are not weldable. Assessing an alloy printability along with other material properties, require experimental testing. Presently, a purely modelling-based approach to select best-performing alloys is beyond reach. Various experimental approaches to rapid alloy design and screening have been reported in AM-literature, which fail to mimic the PBF process conditions entirely.This paper presents a targeted approach and methodology dedicated to novel alloy development for additive manufacturing (NADFAM) and its technical implementation for PBF. The NADFAM approach was applied for a case study featuring the selection of a best-performing titanium alloy for PBF manufacturing of load-bearing biomedical implants. Multiple criteria decision analysis (MCDA) tools were used to rank promising alloys and establish the most suitable to the process and the targeted application.