By use of ICP spectroscopy,energy spectrum analysis,hydrogen tester,image analyzer,the differential scanning calorimetric(DSC)and microscope analysis,the effects of RE on the Porosity,structure and properties of B319 ...By use of ICP spectroscopy,energy spectrum analysis,hydrogen tester,image analyzer,the differential scanning calorimetric(DSC)and microscope analysis,the effects of RE on the Porosity,structure and properties of B319 aluminum alloy were studied.The results show that under the 0.3°C/s slow cooling rate in lost foam casting,the effect of RE on modification and grain size of B319 aluminum alloy is little.With the increase of RE master alloy,the tensile strength and elongation increase.When RE>0.15%,block like La_(2)Si_(2)Al_(3)phase appear,and the tensile strength and elongation decrease.The results also show that the melt hydrogen content and casting porosity can be decreased greatly by adding 0.15%RE to aluminum melt.This is the important reason why RE improves the mechanical properties of casting under lost foam casting condition.展开更多
By using ICP spectroscopy, energy dispersive spectroscopy (EDS) analysis, X-ray diffraction, SEM and microscope analysis, the effects of Mn on the structure of B319 aluminum alloy are studied. The results show that wi...By using ICP spectroscopy, energy dispersive spectroscopy (EDS) analysis, X-ray diffraction, SEM and microscope analysis, the effects of Mn on the structure of B319 aluminum alloy are studied. The results show that without the addition of Mn, there are coral-like Al_2Cu phase and needle-like β-Fe (Al_5FeSi)in the structure of casting with lost foam casting (LFC). Precipitation of Al_2Cu can take place along the long sides of the β needles. Under the rapid cooling rates, such as ones in metallic mold, the Fe phase appears in the form of Chinese script α-Fe. With the addition of Mn, there are Chinese script α-Fe phases(Al_(15) (Mn, Fe)_3Si_2)in the structure of LFC casting. When Fe/Mn≤1.5, the needle-like β-Fe phases transform to Chinese script α-Fe completely. With the decrease of Fe/Mn ratio, the tensile strength σ_b and elongation δ increase, especially the elongation δ increases greatly. When Fe/Mn ratio decreases from 2.5 to 1, the δ increases from 1.2% to 1.9% by 58%.展开更多
In work was researched the composition and structure of high-alloyed aluminum cast iron ЧЮ22Ш. Crystalization of cast iron ЧЮ22Ш (ЧЮ22Ш standard cast iron) was researched by phase transformation, leaking upon...In work was researched the composition and structure of high-alloyed aluminum cast iron ЧЮ22Ш. Crystalization of cast iron ЧЮ22Ш (ЧЮ22Ш standard cast iron) was researched by phase transformation, leaking upon its harden and cooling –down. High-alloyed materials are widely applied as the heat-resistant materials. Overall content of that reaches 30-50% and more. Previous performed researches allowed to optimize the content high-alloyed aluminum cast iron ЧЮ22Ш, to research its structure, casting and operational characteristics, to develop technological mode of melting, casting and thermal / heat treatment casts, to held its industrial examination and to determine perspective direction of its application. However, in present time ability of the aluminum cast iron ЧЮ22Ш is being used not sufficiently.展开更多
A hot compression bonding process was developed to prepare a novel laminated composite consisting of high-Cr cast iron （HCCI） as the inner layer and low carbon steel （LCS） as the outer layers on a Gleeble 3500 the...A hot compression bonding process was developed to prepare a novel laminated composite consisting of high-Cr cast iron （HCCI） as the inner layer and low carbon steel （LCS） as the outer layers on a Gleeble 3500 ther- momechanicat simulator at a temperature of 950 ℃ and a strain rate of 0. 001 s 1. Interfacial bond quality and hot deformation behaviour of the laminate were studied by mierostructural characterisation and mechanical tests. Experi- mental results show that the metallurgical bond between the constituent metals was achieved under the proposed bonding conditions without discernible defects and the formation of interlayer or intermetallic layer along the inter- face. The interfacial bond quality is excellent since no deterioration occurred around the interface which was deformed by Vickers indentation and compression test at room temperature with parallel loading to the interface. After well cladding by the LCS, the brittle HCCI can be severely deformed （about 57 % of reduction） at high temperature with crack-free. This significant improvement should be attributed to the decrease of crack sensitivity due to stress relief by soft claddings and enhanced flow property of the HCCI by simultaneous deformation with the LCS.展开更多
文摘By use of ICP spectroscopy,energy spectrum analysis,hydrogen tester,image analyzer,the differential scanning calorimetric(DSC)and microscope analysis,the effects of RE on the Porosity,structure and properties of B319 aluminum alloy were studied.The results show that under the 0.3°C/s slow cooling rate in lost foam casting,the effect of RE on modification and grain size of B319 aluminum alloy is little.With the increase of RE master alloy,the tensile strength and elongation increase.When RE>0.15%,block like La_(2)Si_(2)Al_(3)phase appear,and the tensile strength and elongation decrease.The results also show that the melt hydrogen content and casting porosity can be decreased greatly by adding 0.15%RE to aluminum melt.This is the important reason why RE improves the mechanical properties of casting under lost foam casting condition.
文摘By using ICP spectroscopy, energy dispersive spectroscopy (EDS) analysis, X-ray diffraction, SEM and microscope analysis, the effects of Mn on the structure of B319 aluminum alloy are studied. The results show that without the addition of Mn, there are coral-like Al_2Cu phase and needle-like β-Fe (Al_5FeSi)in the structure of casting with lost foam casting (LFC). Precipitation of Al_2Cu can take place along the long sides of the β needles. Under the rapid cooling rates, such as ones in metallic mold, the Fe phase appears in the form of Chinese script α-Fe. With the addition of Mn, there are Chinese script α-Fe phases(Al_(15) (Mn, Fe)_3Si_2)in the structure of LFC casting. When Fe/Mn≤1.5, the needle-like β-Fe phases transform to Chinese script α-Fe completely. With the decrease of Fe/Mn ratio, the tensile strength σ_b and elongation δ increase, especially the elongation δ increases greatly. When Fe/Mn ratio decreases from 2.5 to 1, the δ increases from 1.2% to 1.9% by 58%.
文摘In work was researched the composition and structure of high-alloyed aluminum cast iron ЧЮ22Ш. Crystalization of cast iron ЧЮ22Ш (ЧЮ22Ш standard cast iron) was researched by phase transformation, leaking upon its harden and cooling –down. High-alloyed materials are widely applied as the heat-resistant materials. Overall content of that reaches 30-50% and more. Previous performed researches allowed to optimize the content high-alloyed aluminum cast iron ЧЮ22Ш, to research its structure, casting and operational characteristics, to develop technological mode of melting, casting and thermal / heat treatment casts, to held its industrial examination and to determine perspective direction of its application. However, in present time ability of the aluminum cast iron ЧЮ22Ш is being used not sufficiently.
基金Item Sponsored by National Natural Science Foundation of China(51474127)
文摘A hot compression bonding process was developed to prepare a novel laminated composite consisting of high-Cr cast iron （HCCI） as the inner layer and low carbon steel （LCS） as the outer layers on a Gleeble 3500 ther- momechanicat simulator at a temperature of 950 ℃ and a strain rate of 0. 001 s 1. Interfacial bond quality and hot deformation behaviour of the laminate were studied by mierostructural characterisation and mechanical tests. Experi- mental results show that the metallurgical bond between the constituent metals was achieved under the proposed bonding conditions without discernible defects and the formation of interlayer or intermetallic layer along the inter- face. The interfacial bond quality is excellent since no deterioration occurred around the interface which was deformed by Vickers indentation and compression test at room temperature with parallel loading to the interface. After well cladding by the LCS, the brittle HCCI can be severely deformed （about 57 % of reduction） at high temperature with crack-free. This significant improvement should be attributed to the decrease of crack sensitivity due to stress relief by soft claddings and enhanced flow property of the HCCI by simultaneous deformation with the LCS.
