摘要
用拉伸试验、光学显微镜和扫描电镜等研究了退火温度对Ti-50.8Ni-0.1Zr合金超弹性、形状记忆效应、拉伸性能、显微组织和断口形貌的影响。结果表明:350℃和600~700℃退火态Ti-50.8Ni-0.1Zr合金呈现超弹性(SE),350℃退火态合金SE的稳定性最好;400~550℃退火态合金呈现形状记忆效应(SME),450℃退火态合金SME的稳定性最好。随退火温度升高,合金的平台应力先降后升,分别在500℃和650℃达到最小值156 MPa和最大值486 MPa,残余应变先升高后降低,分别在700℃和450℃达到最小值0.0078%和最大值5.6148%。350~550℃退火态合金的强度高于600~700℃退火态,但塑性低于后者;450℃退火后合金的抗拉强度达到最大值,为1493 MPa, 700℃退火后合金的伸长率达到最大值,为39.1%。退火态Ti-50.8Ni-0.1Zr合金的断口形貌呈韧窝状,属微孔聚集型韧性断裂。随退火温度升高,韧窝尺寸增加,合金塑性提高。
Effect of annealing temperature on superelasticity, shape memory effect, tensile properties, microstructure and fracture surface morphology of Ti-50.8 Ni-0.1 Zr alloy was investigated by means of tensile test, optical microscope and scanning electron microscopy. The results show that the alloy annealed at 350 ℃ and 600-700 ℃ presents superelasticity(SE), and the stability of superelasticity of the alloy annealed at 350 ℃ is the best. The alloy annealed at 400-550 ℃ presents shape memory effect(SME), and the stability of shape memory effect of the alloy annealed at 450 ℃ is the best. With the increase of the annealing temperature, the platform stress of the Ti-50.1 Ni-0.1 Zr alloy decreases first and then increases, the minimum value(156 MPa) and the maximum value(486 MPa) of the platform stress are obtained in the alloy annealed at 500 ℃ and 650 ℃, respectively, and the residual strain of the alloy increases first and then decreases, the minimum value(0.0078%) and the maximum value(5.6148%)of the residual strain are obtained in the alloy annealed at 700 ℃ and 450 ℃, respectively. The strength of the alloy annealed at 350-550 ℃ is higher than that of the alloy annealed at 600-700 ℃, but the plasticity is lower than that of the latter. The tensile strength of the alloy annealed at 450 ℃ reaches the maximum value of 1493 MPa, and the elongation of the alloy annealed at 700 ℃ reaches the maximum value of 39.1%. The fracture surface morphology of the annealed alloy is dimpled and belongs to the ductile fracture of microporous aggregation. With the increase of the annealing temperature, the dimple size increases and the plasticity of the alloy increases.
作者
贺志荣
叶俊杰
HE Zhi-rong;YE Jun-jie(School o£Materials Science and Engineering,Shaanxi University of Technology,Hanzhong 723001,China)
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2021年第4期60-67,共8页
Transactions of Materials and Heat Treatment
基金
国家重点研发计划(2016YFE0111400)。
