Mechanical properties and in-situ fabrication of Ni/Ni-aluminide//Ti/Ti-aluminide laminate material by Ti, Ni and Al foils

摘要

Ni/Ni-aluminide/Ti/Ti--aluminide laminatematerial, considered as a functionally gradient material, wasmanufactured by hot-press and Th, Ni and Al foils. Thickintermetallic layers of NiAl and FmAl3 were formed by self-propagating, high temperature synthesis (SHS) reaction, and thinlayers of Ni3Al and TiAl were formed by diffusion in the solidstate at the interface between metal and aluminide layers. Bendingstrength in metal-intermetallic composite depended on loadingdirection in bending test. As a result of fracture toughnessmeasurements, crack arrester had greater fracture resistance thancrack divider due to interruption of crack growth in metal layers.Pure metal Ni and Ti layers showed ductile rupture. Also Ni3Aland NiAl in Ni-aluminide layers revealed cleavage fracture andintergranular fracture, respectively, while Ti-aluminide layersshowed typical cleavage fracture.