基于搅拌摩擦搭接增材的6082-T6铝合金微观组织演变与力学性能分析OA

To address the issue of defects prone to occur in 6082-T6 aluminum alloy during traditional melt-based additive manufacturing,a friction stir additive manufacturing method was proposed for the additive manufacturing of multi-layer 6082-T6 aluminum alloy.Then,a systematic investigation was conducted to characterize the microstructure evalution patterns and their correlations with mechanical properties.Using rolled 6082-T6 aluminum alloy as the substrate and an H13 tool steel stirring tool,five-layer well-formed additive parts were obtained under the process parameters of a single-layer additive thickness of 2 mm,a tool rotation speed of 800 r/min,an additive speed of 160 mm/min,and a plunge depth of 0.1 mm.Characterization and mechanical propertiy evaluation were conduct using OM,EBSD,SEM,hardness testing,and tensile testing.Dynamic recrystallization occurred in the additive zone,presenting fine equiaxed grains with an average grain size of 2.71 μm,accompanied by an increase in the fraction of high-angle grain boundaries to 72%and a significant decrease in dislocation density.The additive zone contained Al5FeSi and Mg2Si phases,among which Mg2Si was an important strengthening phase,and its ability to enhance the mechanical properties of the additive zone was superior to that of fine grain strengthening.Along the additive height,the closer to the bottom of the additive zone,the more thermal cycles it experienced,and the greater the degree of dissolution of the Mg2Si strengthening phase.The microhardness and tensile strength of the additive zone increased along the additive height,with the highest values at the top(65.4 HV0.1 and 210 MPa,respectively),and the fracture surface exhibited a typical ductile fracture mode.The findings indicate that the FSAM technology can effectively produce well-formed 6082-T6 aluminum alloy components.Futhermore,the study clarifies the intrinsic relationship between microstructure and mechanical properties,thereby providing theoretical and experimental support for optimizing the FSAM process for this alloy.