摘要
用示差扫描量热仪研究了退火和时效工艺对Ti-50.8Ni-0.3Cr(原子分数,%)低温超弹性合金相变行为的影响.结果表明.350—450℃退火态Ti-50.8Ni-0.3Cr合金冷却/加热时发生A→R/R→A型可逆相变,500℃退火态合金发生A→R→M/M→R→A型相变,550—600℃退火态合金发生A→R→M/M→A型相变,650℃以上退火态合金不发生相变.退火时间对合金相变行为影响不大.随时效时间t_(ag)延长,300℃时效态合金的相变类型保持为A→R/R→A,400℃时效态合金发生由A→R/R→A向A→R→M/M→R→A转变,500℃时效态合金发生由A→R→M/M→R→A向A→R→M/M→A转变.随退火温度升高,合金的R相变温度θ_R先升高后降低,M相变温度θ_M升高,M相变热滞△θ_M降低.合金经300—500℃时效后,θ_R^(400)>θ_R^(300)>θ_R^(500).随t_(ag)延长,θ_R和θ_M先快速升高后趋于稳定,△θ_M先快速降低后趋于稳定.退火和时效态合金的R相变热滞均在4℃左右.
The effects of annealing and aging processes on transformation behavior of thelow-temperature superelasticity alloy Ti-50.8Ni-0.3Cr（atomic fraction,%） were investigated withdifferential scanning calorimetry.The A→R/R→A（A-parent phase,R-R phase） type reversibletransformation occurred in the 350-450℃annealed alloy upon cooling/heating,the A→R→M/M→R→A（M-martensite） type occurred in the 500℃annealed alloy,the A→R→M/M→A typeoccurred in 550-600℃annealed alloy,and no transformation occurred in the above 650℃annealedalloy.The effect of the annealing time on transformation behavior of the alloy is not serious.Withincreasing aging time t（ag）,the transformation type of 300℃aged alloy still is A→R/R→A,the one of400℃aged alloy changes from A→R/R→A to A→R→M/M→R→A,and the one of 500℃aged alloychanges from A→R→M / M→R→A to A→R→M/M→A.With increasing annealing temperature,the R transformation temperature（θR） of the alloy increases first and then decreases,the Mtransformation temperature（θM） increases,and the M temperature hysteresise（△θM） decreases.After aging at 300-500℃.theθR400θR300θR500.With increasing t（ag）,theθR andθM increase fast firstand then tend to stable,and the△θM decreases fast first and then tends to stable.The R temperaturehysteresises in both the annealed and aged alloys are about 4℃.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2010年第3期329-333,共5页
Acta Metallurgica Sinica
基金
陕西省自然科学基金项目2009JM6010
陕西省教育厅科研计划项目09JK375资助~~
