中文摘要：

采用DSC和SEM等研究了采用不封装热等静压法（CF-HIP）在不同烧结时间下制备的多孔NiTi形状记忆合金时效时的马氏体相变行为。结果表明：经1050℃烧结1h后,合金中主要含有Ti2Ni相和大块的Ni3Ti相,随着烧结时间的延长,大块Ni3Ti相逐渐消失,Ti2Ni相几乎没有变化;将烧结试样经450℃时效后,随着时效时间的延长,Ni4Ti3相在母相中逐渐析出长大,短时烧结试样的马氏体相变过程分为三步（B2→R,R→B19′和B2→B19′）,而长时烧结试样的则为两步（B2→R和R→B19′）。

英文摘要：

Porous NiTi shape memory alloys（SMAs） were fabricated by capsule-free hot isostatic pressing（CF-HIP） sintering for different times.The martensitic transformation behavior of the alloys during ageing was investigated by using DSC and SEM.The results show that the alloy sintering at 1 050 ℃ for 1 h mainly consist of Ti2Ni and large Ni3Ti phases.The large Ni3Ti phases disappeared gradually with prolonging the sintering time,the Ti2Ni phase had little change.The Ni4Ti3 phases gradually precipitated and grew from the parent phase in the sintering samples after aging at 450 ℃ with prolonging the aging time.A three-stage（B2→R,R→B19′ and B2→B19′） martensitic transformation was found in the samples sintering for short time,while a two-stage（B2→R and R→B19′） transformation was found in the samples sintering for long time.