摘要
对TA15合金在SANS CMT4104型高温电子拉伸实验机上进行恒应变速率超塑性拉伸试验,研究了合金超塑性变形过程中空洞演化及断裂行为。结果表明:超塑性变形过程中,TA15合金空洞含量和大小受变形量、应变速率和应变速率敏感性指数m值的影响较大。随变形量增大,空洞分别沿拉伸轴方向和垂直于拉伸轴方向发生了聚合和连接,空洞长大由形核时的一般扩散机制向塑性变形机制转变。TA15合金超塑性拉伸试样断口呈针点状,断口上含有大量的韧窝状空洞,空位聚集-空洞连接是TA15合金超塑性断裂的主要机制。
Constant strain rate superplastic tension experiments of TA15 alloy were carried out on a SANS CMT4104 high temperature electronic tensile testing machine. The cavity evolution and fracture behavior of the alloy during superplastic deformation were studied.The results indicate that the total volume and size of the cavities are greatly influenced by the deformation amount,strain rate and the strain-rate sensitivity exponent m. With deformation amount increasing,aggregation and interlinkage of the cavities take place along the tension axis and the vertical tension axis direction,respectively; and the superplastic diffusion cavity growth model during nucleation is transformed into plasticity controlled growth model. The fracture of the deformed specimen exhibits needle and point shape. A large number of dimple cavities exist on the fracture surface. Vacancy aggregation-cavity interlinkage is the main mechanism of the fracture during superplastic deformation of the TA15 alloy.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2016年第11期50-55,共6页
Transactions of Materials and Heat Treatment
基金
江西省自然科学基金资助(项目号20142BAB206021)
江西省教育厅科技项目(GJJ150735)
轻合金加工科学与技术国防重点学科实验室开放课题研究基金(gf201501006)
南昌航空大学博士启动金资助(项目号EA201303356)
