In order to investigate the change in liquid microstructure of Al-Si alloytreated by electric pulse (EP), X-ray diffraction tests with liquid Al-Si alloy and ZL109 alloytreated or not by EP were carried out. The resul...In order to investigate the change in liquid microstructure of Al-Si alloytreated by electric pulse (EP), X-ray diffraction tests with liquid Al-Si alloy and ZL109 alloytreated or not by EP were carried out. The results show that the number of Al-Si atomic clustersdecreases and that of Al-Al and Si-Si atomic clusters increases for the treated samples. The testswith ZL109 alloy indicate that a large amount of primary crystal Si appears in the solidifiedmicrostructure after treated by EP. It is found that EP can change the microstructure of liquidmetal by affecting the probability of electrons appearing in different atoms (Al and Si) in theliquid metal. The combining force of different atoms decreases relatively, and that of the sameatoms increases, which is the main reason of reducing the atomic cluster with different atoms(Al-Si) and increasing the atomic cluster with the same atoms (Al-Al, Si-Si). The increasing of theatomic cluster with the same atom cluster resulted in the increasing of Si activity and the higherpoint of eutectics in the phase diagram. It makes a lot of primary silicon appeared in ZL109 alloy.展开更多
The structure evolutions of ZL109 alloy and 7050 alloy were studied in the processes of preparing raw billets by low super heat casting, remelting the raw billets, semisolid forming and heat treating components. The t...The structure evolutions of ZL109 alloy and 7050 alloy were studied in the processes of preparing raw billets by low super heat casting, remelting the raw billets, semisolid forming and heat treating components. The thin and symmetrical structure was obtained by using low super heat casting process. The eutectic that lied in the raw billet of ZL109 alloy remelted and produced liquid phase in the process of remelting, but to the 7050 alloy, the eutectic of intergranular and the pointedness of grains was remelted to make the grains more uniform and smooth. In the process of semisolid forming, the primary α and the eutectic inside the ZL109 alloy were separated partly and the grains in the 7050 alloy was conglutinated together. After heat treatment, the eutectic α grains of ZL109 traveled to primary α and shaped the white fishing net like organization; the eutectic Si grains assembled into the black massive particles. As to 7050, after heat treatment, α particles recrystallized and thin grains pattern was obtained.展开更多
In order to increase the modifying effect, the Cu-P master alloy was rapidly solidified with melt-spin method, and the nano-sized ribbon was gained at 105?106 ℃/s. Subsequently, ZL109 alloy was modified by nanocrysta...In order to increase the modifying effect, the Cu-P master alloy was rapidly solidified with melt-spin method, and the nano-sized ribbon was gained at 105?106 ℃/s. Subsequently, ZL109 alloy was modified by nanocrystal and massive Cu-P master alloy, respectively, with molten metal casting method. The results show that the microscopic structure of ZL109 alloy modified by nanocrystal Cu-P master alloy is better than that modified by massive Cu-P master alloy, the original crystal silicon and eutectic silicon are refined more effectively and the mechanical properties are increased evidently: the tensile-strength is increased by 25%, the elongation is increased by 32.26% and the hardness is increased by 17.2%. Therefore, the melt-spin treatment is a feasible method to improve the modifying effect of Cu-P master alloy.展开更多
The structure evolution of the ZL109 alloy in the process of semi-solid squeeze casting and the mechanical properties of the components were investigated. The results show that （1） the eutectic silicon phase in orig...The structure evolution of the ZL109 alloy in the process of semi-solid squeeze casting and the mechanical properties of the components were investigated. The results show that （1） the eutectic silicon phase in original billets is refined in the low super-heat casting process; （2） the eutectic structure in billets starts to fuse and the crystals of the eutectic silicon phase are refined further and sphericized in the remelting process of billets; （3） in the semi-solid squeeze casting process, the sphericity of the a phase and the refining of the silicon phase occur, owing to the friction between solid and liquid; （4） in the process of heat treatment, the eutectic a phase aggregates with the primary a phase and the eutectic silicon pieces aggregate together. The elongation of the semi-solid component after heat treatment rises to 1.42%.展开更多
文摘In order to investigate the change in liquid microstructure of Al-Si alloytreated by electric pulse (EP), X-ray diffraction tests with liquid Al-Si alloy and ZL109 alloytreated or not by EP were carried out. The results show that the number of Al-Si atomic clustersdecreases and that of Al-Al and Si-Si atomic clusters increases for the treated samples. The testswith ZL109 alloy indicate that a large amount of primary crystal Si appears in the solidifiedmicrostructure after treated by EP. It is found that EP can change the microstructure of liquidmetal by affecting the probability of electrons appearing in different atoms (Al and Si) in theliquid metal. The combining force of different atoms decreases relatively, and that of the sameatoms increases, which is the main reason of reducing the atomic cluster with different atoms(Al-Si) and increasing the atomic cluster with the same atoms (Al-Al, Si-Si). The increasing of theatomic cluster with the same atom cluster resulted in the increasing of Si activity and the higherpoint of eutectics in the phase diagram. It makes a lot of primary silicon appeared in ZL109 alloy.
文摘The structure evolutions of ZL109 alloy and 7050 alloy were studied in the processes of preparing raw billets by low super heat casting, remelting the raw billets, semisolid forming and heat treating components. The thin and symmetrical structure was obtained by using low super heat casting process. The eutectic that lied in the raw billet of ZL109 alloy remelted and produced liquid phase in the process of remelting, but to the 7050 alloy, the eutectic of intergranular and the pointedness of grains was remelted to make the grains more uniform and smooth. In the process of semisolid forming, the primary α and the eutectic inside the ZL109 alloy were separated partly and the grains in the 7050 alloy was conglutinated together. After heat treatment, the eutectic α grains of ZL109 traveled to primary α and shaped the white fishing net like organization; the eutectic Si grains assembled into the black massive particles. As to 7050, after heat treatment, α particles recrystallized and thin grains pattern was obtained.
基金Project(E2006000025) supported by the Natural Science Foundation of Hebei Province, China
文摘In order to increase the modifying effect, the Cu-P master alloy was rapidly solidified with melt-spin method, and the nano-sized ribbon was gained at 105?106 ℃/s. Subsequently, ZL109 alloy was modified by nanocrystal and massive Cu-P master alloy, respectively, with molten metal casting method. The results show that the microscopic structure of ZL109 alloy modified by nanocrystal Cu-P master alloy is better than that modified by massive Cu-P master alloy, the original crystal silicon and eutectic silicon are refined more effectively and the mechanical properties are increased evidently: the tensile-strength is increased by 25%, the elongation is increased by 32.26% and the hardness is increased by 17.2%. Therefore, the melt-spin treatment is a feasible method to improve the modifying effect of Cu-P master alloy.
文摘The structure evolution of the ZL109 alloy in the process of semi-solid squeeze casting and the mechanical properties of the components were investigated. The results show that （1） the eutectic silicon phase in original billets is refined in the low super-heat casting process; （2） the eutectic structure in billets starts to fuse and the crystals of the eutectic silicon phase are refined further and sphericized in the remelting process of billets; （3） in the semi-solid squeeze casting process, the sphericity of the a phase and the refining of the silicon phase occur, owing to the friction between solid and liquid; （4） in the process of heat treatment, the eutectic a phase aggregates with the primary a phase and the eutectic silicon pieces aggregate together. The elongation of the semi-solid component after heat treatment rises to 1.42%.
