【摘要】 通过差示扫描量热仪(DSC)、X射线衍射仪(XRD)、扫描电镜(SEM)和透射电镜(TEM)研究了固溶时效对Ti-50.8Ni和Ti-50.8Ni-0.3Cr合金显微组织及相变特性影响。结果表明,固溶后两种合金组织都由原始拉拔纤维组织转变为等轴晶粒,晶粒随固溶温度升高而长大,固溶后母相主要是B2(B19’)相,同时发现存在Ti Ni3粒子。两种合金的马氏体相变峰值温度Mp随着固溶温度升高及时间延长先降低再升高。500℃时效0.5 h时Ti-50.8Ni合金加热/冷却相变类型是A→R→M1→M2/M→Rr→A,Ti-50.8Ni-0.3%Cr合金相变类型是A→R→M1→M2/M→Rr1→Rr2→A;时效1 h时,两种合金加热/冷却相变类型是A→R→M/M→Rr→A,时效2 h后两种合金加热/冷却相变类型是A→R→M/M→A。更多还原

【Abstract】 Effects of solid solution and aging on microstructure and phase transformation behavior of Ti-50. 8Ni and Ti-50. 8Ni-0. 3% Cr alloys were investigated by means of DSC,XRD,SEM and TEM. The results show that the microstructure of the Ti Ni and Ti Ni Cr transforms from the original drawing fibrous structure to equiaxed grains; the grains grow up with the increasing of solid solution temperature,and the parent phase is B2 phase and the second phase particles of Ti Ni3 are also found with the increasing of solid solution temperature and time. The peak temperature of martensitic transformation of the Ti Ni and Ti Ni Cr alloy decreases firstly and then increases in the range from 0 to 10 ℃. After aging at 500 ℃ for 0. 5 h,the phase transformation of the Ti Ni alloy is A→R→M1→M2/M→Rr→A,and the Ti Ni Cr alloy’s is A→R→M1→M2/M→Rr1→Rr2→A. When aging for 1 h,the phase transformation of the two alloys is A→R→MM→Rr→A,and changes into A→R→M/M→A after aging for 2 h.更多还原