Research On Improving The Formability Of Aluminum Alloy Sheets By Laser Local Treatment

As the high specific strength and good processing performance,aluminum and alloys play an irreplaceable role in the automotive industry,aerospace and other fields.However,the aluminum alloy plates have some disadvantage aspect at cold forming process,especially for manufacturing the parts with large drawing depth ratio and complex structure.In order to improve the formability of aluminum alloy plates,the laser local heat treatment technology proposed in recent years,which can significantly improve the forming performance of 6 series aluminum alloys.However,there are few research on non-heat-treated reinforced aluminum alloys such as 5A06,which are widely used in aviation.Therefore,the laser heat treatment process of cold rolled 5A06 aluminum alloy plates was studied in this research.The influence of laser local heat treatment on the forming performance of 5A06 sheet was discussed;and then lied a foundation for the application of laser local heat treatment in aeronautical aluminum alloy.The material used in this research was 1.5mm thickness of H112 state 5A06aluminum alloy plate.Firstly,the influence of laser parameters on the peak temperature of heat treatment were systematically analyzed.The relationship between laser parameters such as laser power,scanning speed,spot diameter and peak temperature were determined.The results show that the peak temperature of laser action is approximately linearly related to the laser power.Then,with the laser local heat treatment on the materials,the influence of peak temperature of laser heat treatment on the mechanical properties,forming properties and microstructure of the test materials were systematically analyzed.The results show that when the peak temperature of laser heat treatment is 500?⁵50?,the Al₈Mg₅ phase on the aluminum matrix is obviously dissolved and the plate has a significant softening effect,the yield strength decreased 35.6%⁴0%,the elongation at break was increased 20.7%⁶7%,the microhardness was reduced by 36.9%,and the forming limit was increased by 50.7%.Finally,finite element method was used by Dynaform software to simulate the forming process of a frame part used on aviation.The local heat treatment layout of the plate was planned and the accuracy of the simulation results were verified by the forming test.The results show that the laser local heat treatment layout of plate can change the timing of material flow in the forming process is changed,so as to improve its forming quality.As a result that the high efficiency forming of aeronautical complex mouth frame is realized.