High-Temperature Deformation and Diffusional Relaxation of Particle-Dispersion Hardened Alloys

颗粒弥散硬化合金的高温变形和扩散弛豫

基本信息

批准号：
07455278
负责人：
KATO Masaharu
金额：
$ 4.8万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07455278/
关键词：
Dispersion-hardened alloys High-temperature deformation Diffusional relaxation Orowan mechanism Creep Elasticity

项目摘要

The main purpose of this research is to understand the role of diffusional relaxation on high-temperature deformation of dispersion-hardened alloys. High-temperature tensile tests were conducted using Cu-SiO_2, Cu-GeO_2 and Cu-Fe alloy single crystals and bicrystals and various stress-strain curves were obtained. In addition, intergranular brittle fracture was found to be very sensitive to the nature of grain boundaries. To quantitatively discuss these experimental results, it was necessary to obtain information on the shape change of dispersed particles that occurs during the deformation. Misorientation-dependent grain-boundary energy must also be characterized. Therefore, basic data on these quantities were also obtained.As theoretical studies, diffusional relaxation around dispersed particles was analyzed by combining mechanics, thermodynamics and kinetics and the rate equations for the relaxation process could be obtained sucessfully. Furthermore, stable shape of dispersed particles and precipitates under a given set of conditions was quantitatively analyzed using micromechanics.In comparison with the high-temperature deformation tests, low-cycle fatigue of Cu-Fe alloy single crystals were performed to reveal the effect of dispersed particles on the development of stable dislocation structure. The similarities and differences in the dislocation structure between high-temperature deformation and cyclic deformation were found very clearly.It is true that this research project has been successfully completed in a sense that it has greatly improved our understanding. What is more important, however, is that this project resulted in the discovery of various new research areas that are essential to understand the high-temperature deformation of dispersion-hardened alloys.

这项研究的主要目的是了解扩散松弛对分散型合金的高温变形的作用。使用CU-SIO_2，CU-GEO_2和CU-FE合金单晶和双晶进行了高温拉伸试验，并获得了各种应力 - 应变曲线。另外，发现晶间脆性断裂对晶界的性质非常敏感。为了定量讨论这些实验结果，有必要获取有关变形过程中发生的分散颗粒的形状变化的信息。还必须表征依赖不良的晶粒 - 结合能量。因此，还获得了有关这些量的基本数据。作为理论研究，通过将力学，热力学和动力学结合分析分散颗粒周围的扩散弛豫，并且可以成功地获得弛豫过程的速率方程。此外，使用微力学对给定条件下的分散颗粒和沉淀物的稳定形状进行了定量分析。在与高温变形测试的比较中，Cu-Fe合金单晶的低周期疲劳进行了进行，以揭示分散颗粒对稳定脱位结构发育的影响。非常清楚地发现了高温变形和循环变形之间的位错结构的相似性和差异。确实，该研究项目已成功完成，从而大大改善了我们的理解。然而，更重要的是，该项目导致发现了各种新的研究领域，这些研究领域对于了解分散性合金的高温变形至关重要。