摘要
In order to improve the performances of the Al-Mg-Si-Cu-Cr-V alloy,various amounts of Mn(0-0.9wt.%) were added.The effect of this Mn on the microstructures and mechanical properties of Al-Mg-Si-Cu-Cr-V alloys in different states,especially after hot extrution and solid solution treatment,was systematically studied using scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),and mechanical tests at room temperature.The results show that 0.2wt.% Mn can both refine the as-cast microstructure of the alloy and strengthen the extrusion+T6 state alloy without damaging the plasticity badly due to the formation of Al 15(FeMn) 3 Si 2 and Al 15 Mn 3 Si 2 dispersoids.Compared with the extrusion+T6 state alloy without Mn addition,the ultimate tensile strength and yield strength of the alloy with 0.2wt.% Mn addition are increased from 416.9 MPa to 431.4 MPa,360.8 MPa to 372 MPa,respectively.The elongation of the extrusion+T6 state alloy does not show obvious change when the Mn addition is less than 0.5wt.%,and for the alloy with 0.2wt.% Mn addition its elongation is still as high as 15.6%.However,when over 0.7wt.% Mn is added to the alloy,some coarse,stable and refractory AlVMn and Al(VMn)Si phases form.These coarse phases can reduce the effect of Mn on the inhibition of re-crystallization;and they retain the angular morphology permanently after the subsequent deformation process and heat treatment.This damages the mechanical properties of the alloy.
In order to improve the performances of the Al-Mg-Si-Cu-Cr-V alloy,various amounts of Mn（0-0.9wt.%） were added.The effect of this Mn on the microstructures and mechanical properties of Al-Mg-Si-Cu-Cr-V alloys in different states,especially after hot extrution and solid solution treatment,was systematically studied using scanning electron microscopy（SEM）,energy dispersive spectroscopy（EDS）,and mechanical tests at room temperature.The results show that 0.2wt.% Mn can both refine the as-cast microstructure of the alloy and strengthen the extrusion＋T6 state alloy without damaging the plasticity badly due to the formation of Al 15（FeMn） 3 Si 2 and Al 15 Mn 3 Si 2 dispersoids.Compared with the extrusion＋T6 state alloy without Mn addition,the ultimate tensile strength and yield strength of the alloy with 0.2wt.% Mn addition are increased from 416.9 MPa to 431.4 MPa,360.8 MPa to 372 MPa,respectively.The elongation of the extrusion＋T6 state alloy does not show obvious change when the Mn addition is less than 0.5wt.%,and for the alloy with 0.2wt.% Mn addition its elongation is still as high as 15.6%.However,when over 0.7wt.% Mn is added to the alloy,some coarse,stable and refractory AlVMn and Al（VMn）Si phases form.These coarse phases can reduce the effect of Mn on the inhibition of re-crystallization;and they retain the angular morphology permanently after the subsequent deformation process and heat treatment.This damages the mechanical properties of the alloy.
基金
financially supported by the Fundamental Research Funds for Central Universities of China(Grant Nos.N110609002and N110408005)
关键词
金属材料
铝材料
铝合金
组织结构
Al-Mg-Si-Cu-Cr-V alloy
Mn content
microstructure
mechanical properties
