Effects of solution-aging treatment on microstructures and properties of Ti-55.06%Ni-0.3%Cr alloy  

固溶时效处理对Ti-55.06%Ni-0.3%Cr合金组织和性能的影响（英文）

作　　者：曾丽舟[1] 罗兵辉[1] 李彬[1] 柏振海[1] 欧阳盛[1] 范文丽[1] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083

出　　处：《Transactions of Nonferrous Metals Society of China》2015年第6期1865-1871,共7页中国有色金属学报（英文版）

基　　金：Project(LH201236) supported by Pre-research

摘　　要：The effects of solution-aging treatment on the microstructures, mechanical properties and internal friction of Ti- 55.06%Ni-0.3%Cr （mole fraction） alloy were investigated by means of tensile test, dynamic mechanical analysis （DMA） and spherical aberration electron microscopy （SAEM）. The results show that the aged alloys with Cr3Ni2 phase always exhibit higher tensile strength and hardness than those of solution-treated alloy without Cr3Ni2 phase, and the aging peak temperature presents at 375 ℃. It is also found that the internal friction peak （tan 6） value decreases with increasing the frequency. There are two internal friction peaks corresponding to the B2（austenite）→R and R→M（martensite） transformations upon cooling, but only one corresponding to the reverse M→B2 transformation upon heating in both solution-treated and 375 ℃-aged alloys, due to the superposition of Mand R phase transformation. Besides, the position of internal friction peaks in the alloy after aging at 375 ℃ shifts to higher temperature. This is attributed to the decrease of Cr and Ni content, and the decline of lattice deformation and transformation resistance, all of which are related to the precipitation of Cr3Ni2 phase in the solution-aged alloys.通过拉伸试验、动态力学分析(DAM)和球差电镜研究固溶时效处理对Ti-55.06%Ni-0.3%Cr(摩尔分数)合金的显微组织、力学性能和内耗性能的影响。结果表明:析出Cr3Ni2相粒子的时效态合金的抗拉强度和硬度总大于无Cr3Ni2析出的固溶态合金,时效峰温度为375°C。固溶态和375°C时效合金的内耗峰值(tanδ)均随频率的增加而降低,降温过程出现奥氏体(B2)→预马氏体相(R)和R→马氏体(M)两个相变内耗峰;升温过程中由于R和M相变的叠加,两种状态合金均只出现一个M→B2相变内耗峰。此外,由375°C时效态合金析出的Cr3Ni2相粒子导致的基体中Cr、Ni含量降低,晶格畸变程度减弱,相变阻力减小,使得375°C时效态合金的内耗峰峰温向高温方向移动。

关 键 词：Ti-Ni-Cr alloy mechanical properties martensite transformation internal friction 

分 类 号：TG166.5[金属学及工艺—热处理]