文档介绍：光学级铝基复合材料热变形行为研究
摘要
在欧美等发达国家,铝基复合材料的工业化生产已经开始,并且被列为2l 世纪新材料应用开发的重要方向。然而,由于在铝基体中加入了大量的硬质相颗粒,铝基复合材料的热加工性能与基体相比要下降很多,这在一定程度上阻碍了铝基复合材料的广泛应用;此外,由于增强体的加入使复合材料的组织变化与控制比传统材料更为复杂。因此,如何选择适当的热加工工艺,提高铝基复合材料的加工性能从而改善产品的显微组织成为目前所面临的关键课题。本文通过建立流变方程对铝基复合材料的热变形进行表征,得到的主要结论如下:
SiCp/2024 铝基复合材料高温热压缩变形时存在稳态流变特征,流变应力随着温度的升高而降低,随着应变速率的增大而提高。SiCp/2024铝基复合材料的高温变形受热激活控制,稳态流变应力可以表示为只包含Z参数的方程。
不同颗粒含量的铝基复合材料在相同条件下会随着颗粒含量的增多而使其流变应力变大,且其流变应力都会随着温度的升高而减小。材料的表观激活能随颗粒含量增加而增大。
关键词:铝基复合材料,流变应力,热激活,动态材料模型
Study on the deformation behavior of optical grade aluminum posite heat
ABSTRACT
Industrialized production of aluminum posites (AMCs) has begun in the United States, Europe and other developed countries, and the material was classified as an important direction of new application materials for 21th century. However, due to the existence of hard particles in AMCs, hot-working ability of the material was much worse than the ability of aluminum alloy, which, to a certain extent, blocks the wide application of the material. Moreover, the existence of the particles will also make it more difficulty to control the microstructure changes of AMCs during hot deformation. Therefore, how to choose the appropriate hot deformation technology to improve the hot working ability of AMCs, and finally improve the microstructure of the production es a critical paper was characterized through the establishment of rheological equation of the aluminum posite thermal deformation, the main conclusions are as follows:
Steady-state flow characteristics were observed during hot deformation of SiCp/posites, and the flow stresses increase with the increasing of strain rate and the decreasing of temperature. The hot deformations of posites are controlled by thermal activation, and the flow stresses under the experimental range can be expressed as a function of parameter Z.
Aluminum posites with different particle content will increase with the particle content and the flow stress es larger under the same co