Al_3Ti/Al composites were in situ fabricated by preheating Al and Ti powder blocks at some temperatures. The reaction process of Ti-(x+3)Al(x>0)system, the microscopic morphology and microstnicture of the products were studied by using DSC、XRD、SEM etc. The reaction mechanism of Ti-(x+3)Al(x>0)system was analyzed through thermodynamics calculation and the established kinetic model. The hardness and wear property of the composites were tested. The influencing factors on the morphology, density and ...