孪晶对多晶纯钛塑性变形影响的实验研究

本文介绍了不同温度下多晶纯钛试件的单调拉伸、压缩试验和不同应变的压缩加卸载试验及其结果,同时介绍了拉断试样以及不同压缩应变下卸载试样的金相观察结果。通过直接比较不同温度下多晶纯钛的单调拉伸、压缩试验结果以及相应的金相分析,得到了由孪晶单独引起的流动应力的增加与应变之间的定量关系。本文还根据Hall-Petch关系和孪晶体积分数的演化方程,建立了孪晶引起的流动应力的增加与应变之间的唯象解析关系。试验结果表明此唯象关系较好地描述了孪晶对多晶纯钛塑性变形的影响。

Experimental Study for the Influence of Twinning on the Plastic Deformation of Pure Polycrystalline Titanium

Quasi-static monotonic tension,quasi-static monotonic compression and loading-unloading compression experiments up to different strains were performed under different temperatures in this paper.And metallographic observations of fractured specimens obtained from quasi-static monotonic tension experiments and specimens with different compression strains obtained from the loading-unloading compression experiments were also carried out.Through comparing the results of quasi-static monotonic tension and quasi-static monotonic compression of polycrystalline pure titanium,and comparing the correspondent optical microscopy observation,the quantitative relationship of the twinning-induced increase of flow stress and the strain is obtained.The phenomenological analytical relationship between the twinning-induced increase of flow stress and the strain is established based on the Hall-Petch mechanism and the evolution equation of the volume fractions of twins.The experimental results show that the present phenomenological relationship satisfactorily describes the influence of twinning on the plastic deformation of polycrystalline pure titanium.