Fabrication, microstructure and mechanical properties of W NiTi composites

Abstract

a b s t r a c tNew two-phase tungsten-based composites containing 88 wt% tungsten powders and 12 wt% nearly equiatomic NiTi alloy deforming by martensite variant detwinning were fabricated by infiltration and hot pressing in this study. 53 Nb 5 composite exhibited a double-yielding phenomenon under compression with an ultimate compressive strength of 3820 MPa and a deformation of 50.4%. In-situ synchrotron high-energy Xray diffraction measurements revealed the first yielding was caused by the martensite reorientation of the NiTi matrix and the second was due to the commencement of massive plastic deformation of the reoriented martensite and is also attributed to the microscopic internal fracturing of the W particles.

Ti3Sn–NiTi Syntactic Foams with Extremely High Specific Strength and Damping Capacity Fabricated by Pressure Melt Infiltration

“…The second method is the introduction of strengthening phases into NiTi SMA matrix composites (SMACs). Soft/hard dual-phase composites have received a lot of attention recently because of their excellent mechanical properties and high damping capacities. − For instance, it was reported that Ti 3 Sn showed excellent damping performance and desirable mechanical properties at a wide temperature range. − Zhang et al − observed that dense NiTi/Ti 3 Sn composites exhibited a high compressive strength of 3.0 GPa and a fracture strain of 33%. This excellent performance was attributed to lattice strain matching and the large interfacial area between the brittle Ti 3 Sn phase and the ductile NiTi phase in the composite.…”