Effect of Starting Powder Properties on the Structure and Mechanical Characteristics of Al-8Cr-1.5Fe Alloy for High-Temperature Applications

Abstract

High-temperature Al—8Cr—1.5Fe alloy is developed for applications in the range from room temperature to 300 °C. The semifinished products are obtained by two technologies based on gas-atomized and water-atomized powders. Structural analysis shows that particle: of the second phase in water-atomized powders are finer and their concentration in the aluminum matrix is higher than that in gas-atomized powders. The rods extruded from water atomized powders have much higher hardness, ultimate strength, and yield stress than those from gas-atomized powders at acceptable plasticity at all temperatures (20, 190, and 300°C). An additional powder metallurgy operation—pulsed hot pressing—does not increase the strength of the semifinished products from either water-atomized or gas-atomized powders. The alloy based on water-atomized 0-63 μm powders shows the maximum strength: strength at 20, 190, and 300 °C is equal to 483, 332, and 261 MPa, respectively.