Ti/Al2O3 functionally gradient material prepared by the explosive compaction SHS process

Ti/Al2O3 Functionally Gradient Material (FGM) was prepared by an explosive compaction/SHS process. Ten sheets of the compounding powder were laminated and pressed to get a green body of FGM. It was then compacted explosively. By burying the explosive compaction body into a stoichiometric Al/TiO2 mix ture and igniting the combustion of the stoichiometric Al/TiO2 mixture, the SHS reaction of the explosive compaction body was initiated by the heat re leased from the combustion of the stoichiometric Al/TiO2 mixture. In this w ay, Ti/Al2O3 FGM was synthesized. The adiabatic temperatures df each gradie nt layer were calculated when the pre-heating temperatures were 298 K and 1 173 K, respectively. The microstructure, composition and properties of Ti/A l2O3 FGM and the reaction mechanism of each gradient layer were studied, it was found that Ti/Al2O3 FGM prepared by the explosive compaction/SHS proce ss had a high density and a high microhardness. Its structure, composition and properties showed apparent gradient distribution. The structure of the standard stoichiometric ratio gradient layer of FGM was a network structure . Its reaction mode could be described as follows: Al powder melted first, then the molten Al penetrated into the TiO2 zone and reacted with TiO2, and big pores were left in the original positions of Al powder. The reaction o f gradient layers with the addition of Al2O3 as diluents was similar to tha t of the standard stoichiometric ratio gradient layer, so were their struct ure and composition. However, the reaction of gradient layers with the addi tion of Ti as diluents was more complex and the composition deviated slight ly from the designed one.