Mechanical Properties of Rapidly Stretched Aluminium and Aluminium-Magnesium Alloy

Abstract

This investigation has been conducted to make clear the effect of strain rate on the internal structure and the mechanical properties of rapidly stretched aluminium and aluminium-magnesium alloy. Pure aluminium (99.99% Al) and aluminium-magnesium alloy (4.65% Mg) specimens have been used in this study. The main results obtained are as follows;(1) The yield strength and the tensile strength of pure aluminium in rapid tensile testing are larger than that in static tensile testing. The strain rate gives a remarkable effect on the resistance in deformation of pure aluminium.(2) The yield strength of aluminium-magnesium alloy in rapid tensile testing is larger than that in static tensile testing, but the tensile strength in rapid tensile testing is smaller than in static tensile testing.(3) The yield strength, the tensile strength and the hardness of rapidly pre-stretched pure aluminium are larger than those of statically pre-stretched sort. It is recognized that this fact is mainly due more to the promoted recovery by static pre-stretching at room temperature than to rapid one.(4) An interesting observation worth mentioning in the static tensile testing of the aluminiummagnesium alloy is that after a certain strain is reached the load starts to oscillate, but in the rapid tensile testing, it is not recognized.(5) The yield strength of rapidly pre-stretched aluminium-magnesium alloy is smaller than that of statically pre-stretched sort, and the tensile strength of the rapidly pre-stretched is almost the same as that statically pre-stretched.