Mechanical properties and microstructural characterisation including high-temperature performance of Al-Mn-Cr-Zr-based alloys tailored for additive manufacturing

Abstract

Powder bed fusion-laser beam (PBF-LB), an additive manufacturing process, takes advantage of rapid cooling rates (103-106 K/s) to enable novel aluminium alloys. This study reports the mechanical properties of one such alloy system (Al-Mn-Cr-Zr based). The alloys based on this system are designed to be precipitation hardenable with high service temperatures. To elucidate the precipitation hardening, three alloy variants were studied involving different heat-treated conditions. Uniaxial tensile testing at room temperature revealed yield strengths between 250–500 MPa with elongation to fracture of 5–25 % with high repeatability. To demonstrate high-temperature resistance, two alloy variants in peak hardened condition were tested at temperatures of up to 573 K. Yield strength up to 170 MPa at 573 K was observed. These properties in combination demonstrate highly competitive Al-alloys for high-temperature applications.

Keywords

• Additive manufacturing
• Powder bed fusion-laser beam
• Aluminium alloys
• Precipitation hardening
• Mechanical properties
• High-temperature materials