Development of ultra-fine grained V–W–Y alloys with superior mechanical properties by effective usage of WC debris introduced during mechanical alloying

Mechanical alloying (MA) is a very effective means for microstructural control. However, MA inevitably accompanies contamination with impurities arising from milling vessels and balls. In this study effective usage of MA processed powders containing WC debris introduced from WC/Co vessels and balls is attempted to develop ultra-fine grained V–W–Y alloys with superior mechanical properties. V–8.4W–1.4Y and V–2.9W–1.6Y (mass%) alloys were fabricated by powder metallurgical methods utilizing MA, HIP and various thermo-mechanical treatments and then subjected to three-point bend impact and static tensile tests. It is shown that the post-HIP thermomechanical treatments lead to significant improvement in the ductility of the alloys: V–8.4W–1.4Y decarburized at 1573 K possesses a grain size of approximately 400 nm and exhibits full bend at 173 K and tensile yield stress of 540 MPa and uniform elongation of 13% at room temperature. Effects of WC debris on the mechanical properties and microstructures in the alloys are discussed.