Precipitation hardening and microstructure evaluation of vapor quenched Al-Ti alloys by transmission electron microscope

Abstract

It is expected that the electron-beam evaporation method can make alloys with excellent mechanical properties and new characteristics. Al-based alloys with additions of Ti have been prepared by electron beam evaporation. The composition dependence of microstructures and mechanical properties have been studied by analysis transmission electron microscope. In the Al-Ti alloy systems, up to Ti contents of 13 at%, the deposit consists of super-saturated solid solution of Al. With increasing Ti content, the Vickers hardness of the deposits increases and the grain size becomes finer. The Al-Ti alloy deposit annealed at 623 K exhibits the highest Vickers hardness with very fine microstructure of α-Al and Al3Ti(Ll2). As annealing at much higher temperature, the hardness becomes lower with microstructure of α-Al and Al3Ti(D022).