Microstructural evolution, microhardness and thermal stability of HPT-processed Cu
Microstructural evolution, microhardness and thermal stability of HPT-processed Cu
复制标题
DOI：
10.1016/s0921-5093(00)00919-9
复制
发表时间：
2000-10-15
期刊：
影响因子：
6.4
通讯作者：
Lowe, TC
中科院分区：
文献类型：
--
作者：
Jiang, HG;Zhu, YT;Lowe, TC
对粗晶铜进行了高压扭转（HPT）和热处理，研究了变形量的增加和随后的退火对组织和显微硬度演变的影响。在低应变下首先形成具有小角度晶界的胞状亚晶。一些低角度的亚晶界转化为高角度晶界在较高的应变，细化的平均晶粒尺寸从200 μ m到150 nm。X射线衍射图显示了晶体织构的形成。显微硬度随扭转应变的增加而单调增加。在未退火的样品中观察到高内应力和非平衡晶界。在低至50摄氏度的温度下退火变形的样品降低了显微硬度，这表明变形诱导的微观结构的热稳定性非常低。差示扫描量热法（DSC）显示在180和280 ° C之间由重结晶引起的膨胀峰。再结晶过程中还形成了退火孪晶。(C)2000 Elsevier Science S.A. All rights reserved.
Coarse-grained copper was subject to high-pressure torsion (HPT) and thermal treatment to study the effects of increasing amounts of deformation and subsequent annealing on the evolution of microstructure and microhardness. Cellular subgrains with low-angle grain boundaries were first formed at low strain. Some of the low-angle subgrain boundaries transformed to high-angle grain boundaries at higher strains, refining the average grain size from 200 mu m to 150 nm. X-ray diffraction patterns showed the formation of crystallographic texture. Microhardness increased monotonically with increasing torsional strain. High internal stress and nonequilibrium grain boundaries were observed in unannealed samples. Annealing as-deformed samples at temperatures as low as 50 degrees C decreased the microhardness, indicating a very low thermal stability of the deformation induced microstructures. Differential scanning calorimetry (DSC) revealed an exothermal peak between 180 and 280 degrees C, caused by recrystallization. Annealing twins were also formed during recrystallization. (C) 2000 Elsevier Science S.A. All rights reserved.