Mechanical and Microstructural Properties of 2618 Al-Alloy Processed by SLM Remelting Strategy

Abstract

Paper deals with the comparison of mechanical properties and microstructure of aluminium alloy 2618 fabricated by Selective Laser Melting (SLM) and material of the same grade manufactured by standard extrusion process. The SLM specimens were fabricated with different processing strategies (meander and remelting). Presence of cracks was found in both cases of used strategies, but in case of meander strategy, crack are of shorter character and distributed rather within individual welds. In case of remelting strategy, cracks are oriented mostly parallel to building direction and transcend fusion boundaries (FB) across several layers. It was found that defects present in microstructure of SLM material significantly affect its mechanical properties. Ultimate tensile strength (UTS) for extruded material reached 392 MPa, while for SLM material produced with meander strategy UTS was 273 MPa and for remelting strategy it was 24 MPa only.