The effects of welding heat input and post-weld heat treatment on the mechanical and microstructural aspects of dissimilarfriction stir welds of age-hardened AA7075-T6and strain hardenable AA5086-H32aluminium alloys w...The effects of welding heat input and post-weld heat treatment on the mechanical and microstructural aspects of dissimilarfriction stir welds of age-hardened AA7075-T6and strain hardenable AA5086-H32aluminium alloys were investigated.X-raydiffraction(XRD)residual stress analysis and tensile testing together with optical metallography and transmission electronmicroscopy(TEM)were performed to assess the effects of process parameters on welded joints.It was discovered that jointsproduced without heat sink exhibited more homogeneous stir zones than other joints.Of the natural aging time studied,higheramount of solid solution during rapid cooling of welds produced higher driving force for increase in hardness in the AA7075sideduring natural aging.Natural aging within stirring zone and thermo-mechanical affected zone of AA7075side resulted in a10to25MPa reduction in the residual stress in these zones;its effect decreased considerably in the welds performed without heat sink.Inaddition,natural aging had no noticeable effect on the joint strength.展开更多
This study investigated the effect of pre-friction surfacing heat treatment of consumable rods and heat input during friction surfacing on the microstructure,mechanical properties,and wear resistance of hypereutectic ...This study investigated the effect of pre-friction surfacing heat treatment of consumable rods and heat input during friction surfacing on the microstructure,mechanical properties,and wear resistance of hypereutectic Al-Si alloy deposited on a commercially pure aluminum substrate.The results show that regardless of the consumable rod’s heat treatment conditions,the coating’s efficiency has increased with the increase in heat input,so the coating efficiency increases by 20%and 30%in the solid solution-treated rod and the artificially aged rod,respectively.By increasing the heat input,the average grain size in the coating fabricated by solid solution-treated rod and artificially aged rod increased from 0.1 to 0.9μm and from 0.2 to 1.3μm,respectively.At constant heat input,the average hardness and wear resistance of the coating created in the solid solution-treated rod are lower than those of the artificially aged rod.By decreasing heat input,the wear loss in the coating fabricated by solid solution-treated rod and artificially aged rod decreased by 10%and 20%,respectively,reaching 0.1 and 0.03μg/m.展开更多
文摘The effects of welding heat input and post-weld heat treatment on the mechanical and microstructural aspects of dissimilarfriction stir welds of age-hardened AA7075-T6and strain hardenable AA5086-H32aluminium alloys were investigated.X-raydiffraction(XRD)residual stress analysis and tensile testing together with optical metallography and transmission electronmicroscopy(TEM)were performed to assess the effects of process parameters on welded joints.It was discovered that jointsproduced without heat sink exhibited more homogeneous stir zones than other joints.Of the natural aging time studied,higheramount of solid solution during rapid cooling of welds produced higher driving force for increase in hardness in the AA7075sideduring natural aging.Natural aging within stirring zone and thermo-mechanical affected zone of AA7075side resulted in a10to25MPa reduction in the residual stress in these zones;its effect decreased considerably in the welds performed without heat sink.Inaddition,natural aging had no noticeable effect on the joint strength.
文摘This study investigated the effect of pre-friction surfacing heat treatment of consumable rods and heat input during friction surfacing on the microstructure,mechanical properties,and wear resistance of hypereutectic Al-Si alloy deposited on a commercially pure aluminum substrate.The results show that regardless of the consumable rod’s heat treatment conditions,the coating’s efficiency has increased with the increase in heat input,so the coating efficiency increases by 20%and 30%in the solid solution-treated rod and the artificially aged rod,respectively.By increasing the heat input,the average grain size in the coating fabricated by solid solution-treated rod and artificially aged rod increased from 0.1 to 0.9μm and from 0.2 to 1.3μm,respectively.At constant heat input,the average hardness and wear resistance of the coating created in the solid solution-treated rod are lower than those of the artificially aged rod.By decreasing heat input,the wear loss in the coating fabricated by solid solution-treated rod and artificially aged rod decreased by 10%and 20%,respectively,reaching 0.1 and 0.03μg/m.
