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

It is expected that the electron-beam evaporation method can make alloys wi th excellent mechanical properties and new characteristics. Al-based alloys with additions of Ti have been prepared by electron beam ev aporation. The composition dependence of microstructures and mechanical pro perties have been studied by analysis transmission electron microscope. In the Al-Ti alloy systems, up to Ti contents of 13 at%, the deposit consis ts 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 hard ness with very fine microstructure of a-Al and Al3Ti(Ll(2)). As annealing a t much higher temperature, the hardness becomes lower with microstructure o f alpha -Al and Al3Ti (D0(22)).