نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشکده مهندسی مواد و متالورژی، دانشگاه علم و صنعت ایران،تهران،ایران
2 هیات علمی دانشکده مواد- دانشگاه علم و صنعت ایران
3 دانشکده مهندسی مواد و متالورژی دانشگاه علم و صنعت ایران، تهران، ایران
4 گروه مهندسی مواد و متالورژی، دانشکده فنی و مهندسی، دانشگاه اراک، اراک، ایران
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
In this study, the hot deformation behavior of Ti6Al4V alloy with an equiaxed microstructure (alpha/beta) was investigated using the Zener–Hollomon parameter and processing maps. Firstly, the stress-strain curves were derived from the hot compression tests, which were conducted at temperatures of 800 to 950°C and strain rates ranging from 10-3 to 1 s-1. Following the determination of the constants of the constitutive equations (ln A, α, n and Q) by using experimental flow curves, predicted flow curves were plotted. On the other hand, microstructural examinations and hardness tests were performed to reveal the microstructural changes and the heterogeneity index. The SimuFact-Forming (FEM) software was also used to simulate stress and strain distributions and dimensional changes in the test samples, as well as force-displacement curves during the hot compression tests. Based on the comparison results, it can be concluded that the hyperbolic sine equation provides more accurate approximations of the Zener-Hollomon parameter and the flow stress. According to the processing maps, the highest power dissipation efficiency was observed within the temperature range of 900 to 950 °C and the strain rate range of 0.3 to 1. Moreover, the unstable zones of processing map were indicated at low temperatures and strain rates (the temperatures between 800 and 840 °C within a strain rate of 10-3 to 0.03). The results showed that the force-displacement curves obtained from finite element simulations were in good agreement with those obtained from experiments.
کلیدواژه‌ها [English]
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