With TEM( Transmission Electron Microscope) ,ithasobserved and analyzedthatforming processof Sub grainsand position offormingfatigue microcracksarein Welded metalsofthe16 Mnsteelundertensile tensilestress. Theresultsi...With TEM( Transmission Electron Microscope) ,ithasobserved and analyzedthatforming processof Sub grainsand position offormingfatigue microcracksarein Welded metalsofthe16 Mnsteelundertensile tensilestress. Theresultsindicatedthattheforming processof Sub grainsfrom dislocationtanglecellstotheSub grains. Thepositionofformingfatigue micro crackisattheoxidativeinterfaceand granular noncrgstallines and Sub boundaries. Thece mentiteineutectoidsafterfracture may beproduced microcracks.展开更多
This article explored the influence of molding density of TiO<sub>2</sub> varistor-ceramic on densification of ceramic body and grain growth. By the main phase and second phase analysis of TiO<sub>2&...This article explored the influence of molding density of TiO<sub>2</sub> varistor-ceramic on densification of ceramic body and grain growth. By the main phase and second phase analysis of TiO<sub>2</sub> varistor-ceramic through XRD and EDAX, the effects of the second phrase on TiO<sub>2</sub> varistor-ceramic were studied. Grain size and its distribution were observed through scanning electron microscope and the density of porcelain body was measured. The effects of grain size, distribution and density of ceramic body on electrical property of TiO<sub>2</sub> varistor-ceramic were the focus issue for analysis. The increased molding density would improve the densifying of magnetic body to some extent and promote grain growth.展开更多
The microstructure of sub-rapid solidification processed AZ61A magnesium alloy was presented and discussed.The results show that the grain size of the foil is significantly refined,and the grain morphology is cellular...The microstructure of sub-rapid solidification processed AZ61A magnesium alloy was presented and discussed.The results show that the grain size of the foil is significantly refined,and the grain morphology is cellular or globular.The eutectic transformation L→α-Mg+β-Mg_(17)Al_(12) and microsegregation in conventionally solidified AZ61A alloy are suppressed to a great extent Theβ-Mg_(17)Al_(12) phases located in theα-Mg grain boundaries are largely decreased due to high solidification cooling rate.As a consequence,the alloying elements Al,Zn,Mn show much higher solid solubility and the sub-rapid solidification microstructure dominantly consists of supersaturatedα-Mg solid solution.The mechanical properties and fractographic analysis reveal that the fracture mechanism and corresponding morphology of the rapture surface of tensile bars are linked to the microstructure obtained and depend on the sub-solidification processes.展开更多
文摘With TEM( Transmission Electron Microscope) ,ithasobserved and analyzedthatforming processof Sub grainsand position offormingfatigue microcracksarein Welded metalsofthe16 Mnsteelundertensile tensilestress. Theresultsindicatedthattheforming processof Sub grainsfrom dislocationtanglecellstotheSub grains. Thepositionofformingfatigue micro crackisattheoxidativeinterfaceand granular noncrgstallines and Sub boundaries. Thece mentiteineutectoidsafterfracture may beproduced microcracks.
文摘This article explored the influence of molding density of TiO<sub>2</sub> varistor-ceramic on densification of ceramic body and grain growth. By the main phase and second phase analysis of TiO<sub>2</sub> varistor-ceramic through XRD and EDAX, the effects of the second phrase on TiO<sub>2</sub> varistor-ceramic were studied. Grain size and its distribution were observed through scanning electron microscope and the density of porcelain body was measured. The effects of grain size, distribution and density of ceramic body on electrical property of TiO<sub>2</sub> varistor-ceramic were the focus issue for analysis. The increased molding density would improve the densifying of magnetic body to some extent and promote grain growth.
基金Projects(50274017,50674018)supported by the National Natural Science Foundation of China
文摘The microstructure of sub-rapid solidification processed AZ61A magnesium alloy was presented and discussed.The results show that the grain size of the foil is significantly refined,and the grain morphology is cellular or globular.The eutectic transformation L→α-Mg+β-Mg_(17)Al_(12) and microsegregation in conventionally solidified AZ61A alloy are suppressed to a great extent Theβ-Mg_(17)Al_(12) phases located in theα-Mg grain boundaries are largely decreased due to high solidification cooling rate.As a consequence,the alloying elements Al,Zn,Mn show much higher solid solubility and the sub-rapid solidification microstructure dominantly consists of supersaturatedα-Mg solid solution.The mechanical properties and fractographic analysis reveal that the fracture mechanism and corresponding morphology of the rapture surface of tensile bars are linked to the microstructure obtained and depend on the sub-solidification processes.
