Microstructure and compressive deformation behavior of W-Ni3Al-Co model alloys by two-step sintering

The regulation of microstructure can improve the mechanical properties of tungsten alloys. To regulate the microstructure, the W-Ni3Al-Co alloys with different Ni3Al/Co ratios were prepared using a two-step sintering method, and the microstructure and compressive deformation behavior were investigated. The results showed that the particle sizes of the W -rich phase in the network structure were refined with the increase of the Ni3Al/Co ratio, and a large fraction of twin boundaries were detected in the adhesive phase. The compressive deformation behavior of a W-7Ni3Al-3Co alloy with excellent compressive properties was investigated by the EBSD technique. The results demonstrated that twins in the FCC binder phase hindered the stress concentration in the binder phase and at the interface of the W/binder phases through twin -dislocation interactions. The W network structure underwent the uniform global deformation that restricted grain boundary sliding during deformation and prevented crack extension and consolidation. Twins in the binder phase and the W network structure were both important factors in improving the compressive properties of W-Ni3Al-Co alloys.