Influence Of6061Al On Microstructure And Properties By CGP

Currently,6061aluminum alloy has been widely used in automobile, aviation and other fields due to its low density, good formability, e-cellent weldability, fine machining performance and easy to coating. Therefore, how to improve its performance to meet the growing demands of industrial production has become a research hotspot. At present, domestic research on average6061aluminum alloy sheet has been more mature, but the study on preparation of fine-grain high-performance6061aluminum alloy sheet is not enough in-depth, high-performance fine grain6061aluminum alloy plates is mainly provided by the import. As one of the effective means to prepare high performance sheet, constrained groove pressing(CGP) has not been further studied at home. So research on producing fine grain6061aluminum alloy plates with CGP is of great significance to promote sheet production technology level.CGP was used to prepare fine grain plate of6061aluminum alloy in this paper. Firstly, heat the6061aluminum alloy sheet at treatment temperature about270℃～330℃for20min～60min as pretreatment. Then, process the pretreated Sheet with CGP for two passes and Measure the change of the average grain diameter during the CGP deformationto observe the influence of deformation pass numbers on6061Aluminum Alloy microstructure. Through e-periments, determine the best e-perimental condition under which the grain refinement is the most significant after two passes of CGP. Take the0°、45°、90°tensile specimen of the aluminum alloy plates before and after the CGP treatment under this e-perimental condition for mechanical properties testing.The results show that6061aluminum alloy plates which were heated at300℃for40min has the minimum average grain diameter in ten groups of e-periments after two passes of CGP, in which the average grain diameter was appro-imately refined from17.4μm to5.14μm after the two passes’s deformation. Among the ten e-periments, under the aboved-mentioned condition, the grain refinement degree of6061aluminum alloy plates was the highest and up to70.5%. During the first pass of CGP, the average grain diameter varied from17.41μm before deformation to the final14.61μm and the degree of the refinement was16.1%. During the second pass of CGP, the average grain diameter varied from14.61μm to the final14.61μm and the degree of the refinement was64.8%. The grain refinement ability of the first pass is far lower than that of the second pass. The strength and elongation of6061aluminum alloy sheets can be significantly improved through the CGP. Take300℃-20min-0°for e-ample, the yield strength of60616061aluminum alloy sheets was rapidly increased to293.2MPa from230.36MPa after two passes and the effect is remarkable.This paper the deformation load formula was deduced using the method of slip-line moulded, and was proved efffective by e-periments. The results show that the deformation load formula can availably predict the load in the process of CGP deformation.