Exploitation on brazing aluminum alloy with high strength and high corrosion resistant
Abstract
In order to meet the market requirements of brazing aluminum alloy for automobile heat exchangers,and avoid a number of registered patent protection in European countries,it is necessary to develop a new aluminum alloy ,so that the corrosion resistance, mechanical properties and process performance meets or exceeds the so-called "long life" aluminum alloy.In this present,the hot deformation behaviors of a new brazing aluminum alloy was studied by means of compression deformation tests on Gleeble 1500 machine at strain rates ranged between 0.01s-1~10s-1 and deformation temperature 350℃~550℃,and associated structural changes were studied by observations of metallographic . The results are shown as following:
1. The true stress-true strain curves of brazing aluminum alloys appears steady-state deformation features apparently. At low strain rate, the true stress increases with true strain rapidly and enters a steady state after reached peak flow. At high strain rate, the true stress decreases sharply after the peak, then the curves enter steady-state deformation stage.
2. Constitutive analysis suggestes that the peak stress can be represented by a Zener-Hollomon parameter in the hyperbolic-sine-type equation, with the hot deformation activation energy of 162.128 kJ/mol.
3. Error analysis shows that relative errors between calculated peak stress and measured peak stress are roughly within ±10%,and average relative errors was 3.37%.The peak stress changed very little after temperature correction.
4. The microstructural shows that inhomogeneous deformation was appeared. it is benefit for recrystallization with the increase of deformation temperature and deformation rate.