Impact Tensile Experimetal Technique And Its Application On Magnesuim-Aluminium Alloy

This dissertation dealed with two problems: the Rotary Disk Impact Tensile technique and its application on the magnesuim-aluminium alloy.The Rotary Disk Impact Tensile technique is a technique being used to study the material property under the impact load, and its fundamentals is same as the SHPB which based on one dimension elastic stress wave theory. The character of the Rotary Disk Impact Tensile device is that there is a short metal bar between the input bar and the baffle, which is elastic-perfectly plastic body. The short metal bar doesn't only create the stress impulse but also filters the impulse. The shape and the connection of the specimen may produce some error of fundamentals. So the dissertation studied the system by experiments and numerical analysis. And the method of calibration and data processing were introduced.Magnesuim-aluminium alloy is light structural materials in common use in aviation and space. The study on it almost focuses on the material structure, galvano-chemiscal and static mechanical property etc. In this dissertation, the author studied the dynamical property of the magnesuim-aluminium alloy with the SHPB and the Rotary Disk Impact Tensile technique. It found that the flow stress that when s =0.005 and the hardening rule are independent on strain_rate, but the failure stress and the failure strain are dependent on the strain_rate. There are some difference between the compressing and the tensiling properties of magnesuim-aluminium alloy, which is of the harden law, the failure stress and the strain. Based on the study , the author used the modified power hardening law to express the relation between the failure stress (strain) and the strain_rate.