利用微反挤压实验,研究了Zr55Cu30Ni5Al10大块非晶合金在过冷液态区域内的超塑性微成形工艺。选取不同的温度(705~735K,5K一个间隔)和不同的冲头速度(2μm/s~8μm/s,递增1μm/s)进行交叉实验,并对挤压成形过程以及影响成形的工艺因素进行了分析。结果表明,非晶合金的微反挤压过程可以分为四个阶段,且零件的挤压深度随成形温度的升高或冲头速度的降低而增大,在710~725K的温度范围内,零件的挤压深度对温度更敏感。低速或高温成形容易使坯料晶化,因此较为理想的挤压工艺条件为725K左右和6μm/s的冲头速度,在此条件下成功地挤压出了壁厚为0.1mm和0.05mm的微型杯零件,SEM显示该成形件杯口整齐,与模具尺寸的符合性较好。
The superplastic micro-forming of Zr55Cu30Ni5Al10 bulk metallic glass in its super-cooled liquid state was studied by employing micro-backward extrusion experiments. Crossover experiments were carried out under different temperatures (705K~735K, at an interval of 5K) and different punching speeds (2~8μm/s, increasing by 1μm/s). The extrusion parameters and the influencing factors of forming process were discussed. The results reveal that the micro backward extrusion process can be divided into four stages. The depth of extruded parts increases with the increase of temperature and the decrease of punching speed, and the depth is more sensitive to temperature at the range of 710~725K. The part will crystallize when formed at low punching speed or high temperature. The best parameters for the extrusion are at the temperature of 725K and the punching speed of about 6μm/s. Micro cup-shaped parts with wall thickness of 0.1mm and 0.05mm are successfully extruded under this condition. The SEM results show that the parts have flat edges and well replicate the mold size.