放电等离子烧结制备超细晶钨钛合金

Ultrafine grained W–Ti alloys prepared by spark plasma sintering

采用放电等离子烧结法制备了Ti原子数分数在15%~30%的钨钛合金,研究了不同Ti含量钨钛合金的相组成、微观结构和超细晶形成机制。结果表明:采用放电等离子烧结技术可在1100℃、保温5 min的条件下制备出含β1(Ti,W)和β2(Ti,W)两相的钨钛合金,在Ti元素偏聚和快速烧结的共同作用下,厘米级块体样品的晶粒尺寸可达亚微米量级,钨钛合金的性能随Ti含量增多而先增强后降低。当Ti原子数分数为25%时,样品相对密度达(98.5±0.1)%,W晶粒平均尺寸约(340±20)nm,硬度和抗压强度分别达到HV(860±2)和(2600±10)MPa。

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 containingβ1(Ti,W)phase andβ2(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 centimetersized 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.