AA5182铝合金两步高速拉伸的试样设计及其性能研究

目的 提高铝合金塑性成形性能,解决高速成形贴模缺陷.方法 设计一种两步高速拉伸试样,在液压式伺服高速拉伸机上开展2次拉伸实验,并采用非接触式光学测量技术(Digital image correlation,DIC)测量全场应变,利用数值模型确定拉伸速度,获得期望的预拉伸应变率和应变.将单次高速拉伸性能与2次不同应变率和...

Two-Step High Speed Tensile Method Design of AA5182 and Research on Its Tensile Property

This paper aims to improve the plasticity of aluminum alloy forming and to solve the defect of die fitting in high-speed forming. In this paper, two-step tensile experiments were carried out on a hydraulic servo high speed tensile machine with a designed two-step high-speed tensile specimen, and the filed strain was measured by digital image correlation (DIC) system with a high speed camera. The numerical model was used to guide the setting of tensile velocities in the experiment so as to obtain the desired strain rates and strains after pre-stretching. The tensile properties of the specimens were compared with those of the specimens under single high-speed tension and two steps of different strain rates and pre-strains. Conclusion could be made that the properties of aluminum alloy under two-step high speed stretching were better than that of single stretching. And the tensile strength increased by 10% and the fracture strain increased by 14.5%. The results showed that the designed specimen could meet the requirements of two-step stretching. The size and tensile speed of the specimen pre-tension area would affect the specimen pre-strain and pre-strain rate, as well as the final fracture strain.