A retrogression process was applied to AA7075alloy at180,240and320°C for1,30,50,70,90and120min.After the retrogression,aging treatment was reapplied with T6conditions(120°C,24h).The mechanical properties of ...A retrogression process was applied to AA7075alloy at180,240and320°C for1,30,50,70,90and120min.After the retrogression,aging treatment was reapplied with T6conditions(120°C,24h).The mechanical properties of aged samples were determined by V-Charpy and hardness tests and also,physical properties of samples were determined by electrical conductivity tests.Moreover,microstructural properties were characterized by light microscope and transmission electron microscope.The results show that the effects of the temperature and the duration of the retrogression and reagent on the impact toughness and hardness are related to the precipitates at the grain boundary.展开更多
Cooling slope casting has been applied to aluminium casting alloys for producing ingots with non-dendritic microstructure.Semi-solid forming of the AA7075 was studied via cooling slope casting,reheating and thixoforgi...Cooling slope casting has been applied to aluminium casting alloys for producing ingots with non-dendritic microstructure.Semi-solid forming of the AA7075 was studied via cooling slope casting,reheating and thixoforging processes in order to determine the effect of semi-solid casting on the microstructure of the alloy.AA7075 ingots with non-dendritic microstructure were produced with cooling slope pouring.Castings were characterized by light microscopy,image analysis,scanning electron microscopy and EDS analysis.The resulting structures are promising in terms of grain size and sphericity.It was realized that grain coarsening may occur very suddenly in the reheating process.Cooling slope castings were obtained with 30°and 60°inclination angles,and in comparison,60°castings showed better results.Moreover,by using short reheating periods,semi-solid forging causes trace formation in the solid grains.展开更多
基金supported by Yildiz Technical University Scientific Research Project Unit under Contract No:2016-07-02-DOP02
文摘A retrogression process was applied to AA7075alloy at180,240and320°C for1,30,50,70,90and120min.After the retrogression,aging treatment was reapplied with T6conditions(120°C,24h).The mechanical properties of aged samples were determined by V-Charpy and hardness tests and also,physical properties of samples were determined by electrical conductivity tests.Moreover,microstructural properties were characterized by light microscope and transmission electron microscope.The results show that the effects of the temperature and the duration of the retrogression and reagent on the impact toughness and hardness are related to the precipitates at the grain boundary.
文摘Cooling slope casting has been applied to aluminium casting alloys for producing ingots with non-dendritic microstructure.Semi-solid forming of the AA7075 was studied via cooling slope casting,reheating and thixoforging processes in order to determine the effect of semi-solid casting on the microstructure of the alloy.AA7075 ingots with non-dendritic microstructure were produced with cooling slope pouring.Castings were characterized by light microscopy,image analysis,scanning electron microscopy and EDS analysis.The resulting structures are promising in terms of grain size and sphericity.It was realized that grain coarsening may occur very suddenly in the reheating process.Cooling slope castings were obtained with 30°and 60°inclination angles,and in comparison,60°castings showed better results.Moreover,by using short reheating periods,semi-solid forging causes trace formation in the solid grains.
