Fabrication, microstructure and mechanical properties of novel NiTi/(Al3Ti + Al3Ni) laminated composites

In this work, a novel kind of NiTi/(Al3Ti + Al3Ni) laminated composites were fabricated successfully using NiTi foil and Al alloy foil for the first time via vacuum hot pressing method. The microstructure of NiTi/(Al3Ni+Al3Ti) laminated composites was analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM), which indicated that this novel composite consists of two main layers: a NiTi layer and an intermetallic layer, and the newly formed intermetallic layer contains two phases, i.e. Al3Ni and Al3Ti. Otherwise, the mechanical properties, including tensile and compressive performance, of this composite were investigated to exploit its potential application. The quasi-static tensile results indicated that the average ultimate tensile strength (UTS) of this composite is 266.1 MPa with relatively high failure strain (average 16.1%). The fracture process shows three basic stages: (Ⅰ) elastic deformation stage, (Ⅱ) stress induced martensite (SIM) phase transformation stage (and the fracture of some intermetallics), and (Ⅲ) the fracture of NiTi layer. The quasi-static compression results showed that NiTi/(Al3Ti + Al3Ni) laminated composites possess high strength (quasi-static compressive strength is 1114.5 MPa) with load perpendicular to layers. [Display omitted] •A new class of NiTi/(Al3Ti+Al3Ni) laminated composites is synthesized.•Each phase of the laminated composites is determined.•Tensile and compressive properties of this kinds of laminated composites are analyzed.•Fracture mechanisms of NiTi/(Al3Ti+Al3Ni) laminated composites are discussed.