6005 Aluminum Alloy Organization Performance And Quenching Sensitivity Study

This article studied the solution and aging system and quench sensitivity of6005aluminum alloy by mechanical testing, Brinell hardness test, microstructure observation and analysis and computer software simulation and so on. We drew the isothermal transformation curve using experimental data, and compared it from the one through computer software simulation. At the same time, we studied the influence of different quench system to the stress in the alloy by finite element software system. The results show that:1) The suitable solution-aging system of6005alloy is535℃×50min solid solution and water quenching,180℃×6h aging. In this condition, the6005alloy tensile strength, yield strength and elongation are300MPa,288MPa and12%.2) The alloying elements Fe, Si and Al in6005alloy form impurity phases for the heat-stable, which dose not change in heat solution, and present in the extruded, solid solution and aging state of6005alloy.3) The TTT curve and TTP curve of6005alloy are"C" type, the nose temperature is340℃, the time of gave birth is9s,6005alloy has high quench sensitivity, and the quenching sensitivity interval is280℃-415℃.4) The phase transformation kinetics equation of6005alloy at340℃isothermal treatment is f=1-exp(-0.006t0.9457).5) The supersaturated solid solution of6005alloy decompose and precipitate second phase particles during the isothermal process, and has the maximum rate at the tip temperature of340℃,6005alloy precipitation sequence is:supersaturated solid solution-β"-β’-β.6) The TTT curve and TTP curve of6005alloy can be obtained by JmatPro5.1simulation software simple and quickly, and the result is the same as what is drawn through the experimental data.7) Abaqus CAE software can simulate the temperature field and stress field at different quenching systems through the curves of physical parameters changing with temperature which get from JmatPro5.1software. Compared with the one-time quenching section, to ensure the basic performance is not declining, sub-quenching can reduce the stress of the alloy.8) The outlet temperature (the equivalent of online quenching temperature) of6005profile alloy should be higher than500℃after online extrusion quenching. The speed can be slowed from500℃to415℃, and higher than9℃/s form415℃to280quenching sensitive areas. For one thing, this can reduce the residual stress. For another, this can avoid the decomposition of solid solution, which can guarantee the mechanical properties.