Preparation And Mechanical Properties Of NiTi Fiber Reinforced Ti/Al 3 Ti Layered Composites

Ti/Al₃Ti is a new laminated composite with high strength, high modulus, low density characteristics, but it has a poor ductility. In this study, NiTi fiber-reinforced metal-intermetallic-laminated ? MIL ? composite NiTi-Ti/Al₃Ti was fabricated successfully using Ti, Al foils and NiTi fibers by vacuum hot press sintering. In order to study the influence of volume fraction of each phase mechanical performance of NiTi fiber reinforced Ti-Al₃Ti metal-intermetallic-laminated composite,the compression, three-poin bend tests were performed in this work.The experimental results showed that there is no obvious defect in microstructure of NiTi fiber reinforced Ti-Al₃Ti metal-intermetallic-laminated composite prepared by vacuum hot-pressing sintering, the raw material, NiTi fibers can be clearly seen, and interface of laminate combined well, there is only a small amount of residual aluminum. Quasi-static and dynamic commpression tests indicated that the compressive strength was higher when the loading is perpendicular to the layer compared with the loading parallel to the layer. When the loading is perpendicular to the layer,the compressive strengthes of 45%Ti-3%NiTi MIL composite are -1280 MPa under quasi-static strain rate and -1420MPa under high strain rate,respectively.The 3-point bend tests demonstrated that the bending strength and the energy absorption increase with increasing volume fraction of Ti and NiTi when the loading is perpendicular to the layer. Failure modes in quasi-static and dynamic loading tests are similar, while the damage is greater in the dynamic loading.