Synthesis, characterization and mechanical properties of (Al, Cu)3Ti powder blend by mechanical alloying

Abstract

In the present investigation, an attempt has been made to study the formation of intermetallic compound for Al70Cu22Ti8 alloy composition by mechanical alloying. Elemental powder of Al70Cu22Ti8(all in wt. %) composition was milled in a Fritsch pulverisette planetary mill for 50h under toluene. Powder of 1wt. % Y2O3 and 1wt. % TiO2 were added separately to the 50 h milled base alloy powder to study the effect of oxide dispersion. X-Ray diffraction shows the formation of AlCu, AlTi3, and Cu9Al4intermetallics compound formation after 50h of milling. There is a formation of Al2O3 for Y2O3 and TiO2 dispersed base alloy sintered at all temperatures. It has been observed that the rate of reduction of size is very fast up to 10h of milling and after that it is gradually decreases and remains constant after 10 h of milling. Particle size has been reduced from 45 ƒÝm to 6 ƒÝm after 50 hour of milling. DSC study shows the presence of small endothermic peak at 535C for formation of Al2Cu and two exothermic peaks at 701C and 850C for formation of other intermetallics like AlTi3, Cu9Al4andAlCu. A maximum of 81% theoretical density was obtained for the composite powder mixture sintered at 1100C for 1h. A maximum Vickers microhardness of 449, 649, 872HV were obtained for base alloy, Y2O3 and TiO2 dispersed alloy sintered at 1100C for 1h respectively. It was also found that TiO2 and Y2O3 dispersed base alloy have higher wear resistance than base alloy.