Abstract
Abstract: Ceramic Phase transformation in laser melting zone on composite bed of Zn-Al based Al2O3 ceramic is reported in this paper. A12O3(99%)layer was sprayed on the surface of parent material by plasma spraying equipment, and the sprayed layer was melten by transverse flowing CO2 laser . The microstructure, composition and distribution of the ceramic phase were studied Through these researches, we get three conclusions: 1. Two layers are formed on the basal body after sprayingα-A12O3 ceramic. The superficial layer is ceramic phase and the transition layer is binder layer of ceramic phase and basal body; 2.Superficial layer is formed mainly byα-A12O3 with littleγ-A12O3 after sprayingα-A12O3;3. Theα-A12O3 and γ-A12O3 ceramic phases in superficial layer transform intoδ-A12O3 ,which is body-centred tetragonal (bct). Ceramic-phase grains in molten pool are mainly distributed in superficial layer, and there are also some ceramic grains in subsurface and transition layer.
