HIGH-TEMPERATURE PERFORMANCE OF DISPERSION-STRENGTHENED AL-TI ALLOYS PREPARED BY MECHANICAL ALLOYING

Dispersion-strengthened Al-Ti alloys were prepared by the mechanical alloying (MA) process and hot consolidation method, and their high temperature mechanical properties and oxidation properties were investigated. The tensile strengths of MA Al-Ti alloys were substantially higher than those of conventional Al alloys such as 7075 and 2024 grades at temperatures above 150-degrees-C. The compressive strength and the yield strength of MA Al-8wt.%Ti at 350-degrees-C with a strain rate of 1 x 10(-4) s-1 were 233 MPa and 186 MPa respectively. The measured parabolic rate constant k(p) in oxidation of the MA Al-8wt.%Ti alloy at 600-degrees-C was a much lower value, approximately 1.12 X 10(-13) g2 cm-4 s-1, which revealed that the oxidation resistance of the MA alloy was much better than that of the 2024-TB Al alloy.