Characterization of Ti-Al surface alloy formed by pulsed electron-beam melting of film-substrate system
Résumé
This paper presents our first results of an ongoing research dedicated to the analysis of Ti-Al surface alloy obtained by a new duplex e-beam treatment. The crack-free Ti3Al-based surface alloy was synthesized by cyclic pulsed melting/mixing of pre-deposited Al film (100nm) on Ti substrate with a low-energy (10–20keV) high-current electron beam (3μs, 3.5J/cm2) followed by additional pulsed e-beam melting (100μs, 15keV, 15J/cm2). The surface analysis has revealed the complexity of the local transformation paths associated with this synthesis mode. A fairly good surface chemical homogeneity was obtained but a duplex microstructures formed because of local changes in the primary phase under rapid solidification and the subsequent modifications of the solid state transformation paths.