An accurate loading experimental measurement device for superplastic free bulging  

作　　者：SONG YuQuan MA PinKui GUAN XiaoFang 

机构地区：[1]Superplasticity and Plasticity Research Institute, Jilin University

出　　处：《Science China(Technological Sciences)》2013年第9期2109-2114,共6页中国科学（技术科学英文版）

基　　金：supported by the Natural Science Foundation of Jilin Province (Grant No. 201115015);the National Natural Science Foundation of China (Grant No. 51005099)

摘　　要：Superplastic alloy has very strong structure sensitivity. Superplastic bulging with a die of the plate is related not only to stress state but also closely to loading paths. It is an important basis for bulging forming with a die to study deformation law and experimental apparatus for superplastic free bulging, because the boundary of test piece is fixed and friction is insignificant for free bulging. In the paper, a pure high-pressure argon gas source is used as the loading media after it is heated by the heating system outside the furnace, which improves the heating efficiency and temperature uniformity of the test piece. The photoelectric non-contact measurement device can avoid negative influence on the additional stress and uneven temperature at the peak of bulging part caused by push rod in the contact measurement. The temperature and pressure of the test piece in cylindrical insulation furnace with blank holder give feedback control to improve the control precision. In loading gas channels, the pressure is adjusted by accurately measuring and controlling the rotation angle of the stepping motor, and is loaded by an electro-magnetic valve. It significantly increases the response characteristics of the control pressure. This paper also introduces steps and methods to realize several typical loading paths, such as constant pressure, jump pressure and additional back & differential pressure loading. These provide a new way to measure the strain rate sensitivity index m value and improve the deformation speed of superplastic free bulging.

关 键 词：superplastic bulging photoelectric conversion experimental measurement typical loading path 

分 类 号：TG113[金属学及工艺—物理冶金]