Effect of different processing on the microstructure and mechanical properties of Al67Mn8Ti24Nb1 alloy

The microstructures and mechanical properties of a Nb-modified multiphase Al3Ti-based alloy prepared by different techniques such as-cast, spray forming and mechanical milling have been investigated. The dendrites in the as-cast Al67Mn8Ti24Nb1 experienced considerable fragmentation in the spray forming or ball milling process. The microstructure with an equiaxed L1(2) matrix and homogeneous distributed second phase was obtained in almost all part of the spray formed deposit and its porosity was low. Al67Ti24Mn8Nb1 alloy consolidated from high energy ball-milled powders shows higher strength and better fracture toughness than as-cast or sprayed alloy, which result in fine grain size about 1 mum and the secondary phase particles were refined to the order of hundred nanometers in the ball-milled powder consolidated alloy. (C) 2004 Elsevier B.V. All rights reserved.