Hydrostatic Extrusion Experiment on AZ80 Magnesium Alloy Tube-Expanding Forming under Ultra-High Pressure

4th Annual International Workshop on Materials Science and Engineering

Fang, Zechen^1 ; Cai, Hongming^1 ; Yuan, Renshu^1 ; Zhang, Xinping^1 ; Wu, Zhilin^1

Nanjing University of Science and Technology, Nanjing

210094, China^1

关键词: Elongation percentage;    Homogenization temperatures;    Hydrostatic extrusions;    Post-treatment process;    Preheating temperature;    Strength and elongations;    Systematic experiment;    Tensile yield strength;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/381/1/012179/pdf
DOI  :  10.1088/1757-899X/381/1/012179

来源: IOP

【 摘 要 】

A series of systematic experiments were completed on self-developed ultra-high pressure hydrostatic extrusion equipment to determine the effects of key process parameters on AZ80 magnesium alloy tube-expanding forming. Compared with other parameters, extrusion ration has a significant impact on maximum extrusion pressure and unloading pressure. Through material performance tests, highest average tensile ultimate strength (380.0Mpa) and average tensile yield strength (369.3Mpa) was obtained at homogenization temperature of billet 400°C, homogenization time of billet 32h, preheating temperature of extrusion cylinder 180°C, extrusion ratio 2.77 and angle of core die 120°, accompanied by elongation percentage 7%. In the condition of experiment NO.13 (homogenization temperature of billet 400°C, homogenization time of billet 16h, preheating temperature of extrusion cylinder 220°C, extrusion ratio 1.25 and angle of core die 120°), tensile strength, yield strength and elongation percentage achieved a balanced combination with relative low extrusion pressure. Metallographic test also indicates that the ductility of expanding forming tube still has improving potential by annealing recrystallization or other post-treatment processes which is effective to completely eliminate the bulk grain.