Transactions of Materials and Heat Treatment

Title：Evolution laws of precipitated phases and strength prediction model for 7075 aluminum alloy during hot forming

Authors： Hu Zhili1 2 3 Cheng Binyang1 2 3 Wei Pengfei1 2 3 Li Huanhuan4

Unit：

KeyWords：

ClassificationCode：TG146.21

year,vol(issue):pagenumber：2021,46(9):105-111

Abstract：

The dislocations generated after hot forming caused the nucleation and growth of precipitated phases on the matrix and dislocation to compete during the aging process, and according to the rheological stress Arrhenius equation obtained by thermal tensile experiment of 7075 aluminum alloy, the precipitation behavior and hardening behavior of dislocation for the precipitated phase during the thermal deformation process were described. Therefore, based on crystallography and precipitation dynamics, the correlation relationship among volume fraction of the precipitated phases, unit atomic volume of the precipitated phases and kinetics after the thermal stamping of aluminum alloy were analyzed by thermal tensile experiment and TEM, the size evolution of the precipitated phase was analyzed by thermodynamics, and the precipitation evolution model and yield strength prediction model for precipitated phases of HFQ process were established by combining the rheological behavior of material with the yield strength. The results show that the volume fraction of enhanced precipitated phase η′ increases rapidly with the extension of aging time of 0-28 h and reaches the peak, and then presents a stable period, next decreases rapidly. In addition, the size of enhanced precipitated phase η′ also increases with the increasing of aging time of 0-28 h and deformation amount of 10%-25%.

Funds：

国家重点研发计划(2019YFB1704500)；国家自然科学基金资助项目(51775397)；湖北省重点研发计划项目(2020BAB140)；湖北省技术创新重大专项(2019AAA007)；武汉市科技成果转化专项(2019030703011511)

胡志力（1983-），男，博士，教授 E-mail：zhilihuhit@163.com

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