.7050 Thick Aluminum Alloy Plate Quenching Temperature Field And The Numerical Simulation Of Internal Stress Field

Aluminum alloy 7050 thick plate stretched with high strength and toughness and low residual stress is the necessarily key material for modern aerospace and weaponry industry. The strength of this alloy is greatly improved after the solution heat treatment, quenching and age harding. Whilst the rapid cooling ensures good mechanical properties, the thermal gradient can be large enough to produce high levels of residual stress. Reducing the cooling rates during the quench can reduce the magnitude of residual stress; however it can also be detrimental to mechanical properties, particularly for quenching sensitive alloys. So the perfect quenching is to reduce residual stress while improve the strength of alloy.The mechanical and thermalphysical parameters are measured by Gleeble-1500 Thermal Analogue and Laser Flash Apparatus JR-3. The computational models of heat fields and stress fields for quenching 7050 thick aluminum alloy plates are based by the Finite Element Analysis software MSC. Marc, and which are optimized too.The result indicates that, when quenching the alloy, the surface of alloy goes through tensile stress to compressive stress, while the center of that goes through compressive stress to tensile stress. Then the feature of tensile stress on surface and compressive stress in center is formed.The effect of conditions of interface heat transfer for the surface of alloy is outclassing to the center of that. The excessively intense surface heat transfer induces enormously high residual stress, but the cooling rate of aluminum alloy plate especially the center of that can't be obviously improved. For instance of 120mm thick plate, the difference of cooling rate of center did not exceed 2%, and the residual stress increased more than 10% when selecting the heat transfer coefficient for 10 000 and 15 000. As the result, the magnetic field conditions of quenching should be logically selected based on the requirement of microstructure and strength of the materials, and do efforts to reduce the residual stress of quenching.