Microstructure and Mechanical Properties of Al–(12-20)Si Bi-Material Fabricated by Selective Laser Melting

Abstract

In this study, a combination of Al−12Si and Al−20Si (Al−(12-20)Si) alloys was fabricated by selective laser melting (SLM) as a result of increased component requirements such as geometrical complexity and high dimensional accuracy. The microstructure and mechanical properties of the SLM Al−(12-20)Si in as-produced as well as in heat-treated conditions were investigated. The Al−(12-20)Si interface was in the as-built condition and it gradually became blurry until it disappeared after heat treatment at 673 K for 6 h. This Al−(12-20)Si bi-material displayed excellent mechanical properties. The hardness of the Al−20Si alloy side was significantly higher than that of the Al−12Si alloy side and the disparity between both sides gradually decreased and tended to be consistent after heat treatment at 673 K for 6 h. The tensile strength and elongation of the Al−(12-20Si) bi-material lies in between the Al−12Si and Al−20Si alloys and fracture occurs in the Al−20Si side. The present results provide new insights into the fabrication of bi-materials using SLM.

Keywords

• Al–Si
• selective laser melting (SLM)
• microstructure
• mechanical properties