Microstructure and mechanical properties of rapidly solidified AI‐3Cr‐0.3Mo alloys

Abstract

The evolution of the microstructure and mechanical properties of an Al‐3 at%Cr‐0.3 at%Mo alloy was studied using centrifugally atomised powder and rod extruded from it. The powder showed different microstructures: cellular, globular or spherulitic, with dendrite rosettes, or mixed structures. The intermetallic A1₁₃(Cr_xMo_1‐x)₂ was present from the as‐quenched state and 0.36 at%Cr was retained as solid solution. In the finer powder the alpha phase solidified and the intermetallic then precipitated, forming spherulites. Hot extrusion did not damage the powder microstructure. Mechanical properties at room temperature were poor, but after annealing at 300 °C were better than in conventional alloys. Fracture occured in two different modes, depending on the material's heat treatment.