Hydraulic Bulge Test of Al and Copper Tubes

Abstract

This work aims to find forming limit diagram and mechanical properties experimentally to measure formability by hydraulic bulge test and tensile test, and determination the values of the bursting pressure and final thickness in the final stage at bursting experimentally and numerically by using program (ANSYS 11) to perform numerical simulation for copper and aluminum alloy (6060) tubes before and after heat treatment by hydraulic bulge test. In this work, used two types of tubes with dimensions for copper of (L0=150mm, d0 = 41.275mm, t0 = 1.06mm) and for aluminum alloy (6060) are (L0=150mm, d0 = 60mm, t0 = 2 mm). Applied heat treatment (annealing) of copper and aluminum tubes at temperature (450°C, 400°C).the holding time in the furnace was 1 hour and then cooled in the furnace. Has been printed square grid by screen method with dimensions (5x5 mm) for copper and aluminum tubes before and after heat treatment and with dimensions (2.5x2.5 mm) for tensile samples of copper and aluminum before and after heat treatment. Strain Measurement accomplished by using image processing technology using MATLAB by measuring the dimensions of the grid printed before and after the deformation and then measure the true strain on tensile samples and tubes used in the tensile test and hydraulic bulge test before and after heat treatment. The results show that, the values of the bursting pressure and final thickness in the final stage at bursting for copper tube before and after treatment is (29MPa, 27MPa)،( 0.892mm, 0.621 mm) and for aluminum tube before and after treatment is (19MPa, 16MPa),( 1.789mm, 1.4872 mm). Increasing formability and decreasing bursting pressure of tubes after heat treatment of increasing the strain hardening exponent (n) of tubes.