Ultrafine grained W–Ti alloys prepared by spark plasma sintering

The W–Ti alloys with the Ti atomic fraction in the range of 15%~30% were prepared by spark plasma sintering in this paper. The phase composition, microstructure, and formation mechanism of the ultrafine grained W–Ti alloys with the different Ti content were studied. The results show that, the W–Ti alloys containing β₁(Ti,W) phase and β₂(Ti,W) phase can be prepared by spark plasma sintering at 1100 ℃ in 5 min. Under the combined action of Ti segregation and rapid sintering, the grain size of the centimeter-sized bulk samples is up to sub-micron scale, and the properties of the W–Ti alloys first increase and then decrease with the increase of Ti content. When the Ti atomic fraction is 25%, the relative density of the samples is (98.5±0.1) %, the average size of W grains is about (340±20) nm, and the hardness and compressive strength are HV (860±2) and (2600±10) MPa, respectively.