| Ni/Ni-aluminidel/Ti/Ti-aluminide laminate material, considered as a functionally gradient material, was manufactured by hot-press and Ti, Ni and Al foils. Thick intermetallic layers of NiAl and TiAl₃ were formed by self-propagating, high temperature synthesis (SHS) reaction, and thin layers of Ni₃Al and TiAl were formed by diffusion in the solid state at the interface between metal and aluminide layers. Bending strength in metal-intermetallic composite depended on loading direction in bending test. As a result of fracture toughness measurements crack arrester had greater fracture resistance than crack divider due to interruption of crack growth in metal layers. Pure metal Ni and Ti layers showed ductile rupture. Also Ni₃Al and NiAl in Ni-aluminide layers revealed cleavage fracture and intergranular fracture, respectively, while Ti-aluminide layers showed typical cleavage fracture. |
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