Electric pulse modification （EPM） is a novel technique that reduces grain size by altering the structure of a melt. It was investigated that the response of the casting structure of high pure aluminum to EPM in diff...Electric pulse modification （EPM） is a novel technique that reduces grain size by altering the structure of a melt. It was investigated that the response of the casting structure of high pure aluminum to EPM in different superheated melts. The results indicate that the grain refining effect of a given pulse electric field holds an optimal temperature range, moreover, a lower or higher superheated temperature will both disadvantage the improvements of casting structure. It essentially lies in the cooperative action between the distorted absorption of clusters and the activated capability of atoms in the aluminum melt.展开更多
The effects of various amount of Y and La on the cast structure.the fluidity,the wearability and corrosion resistance of the high manganese aluminium bronze have been investigated.The results have shown that a proper ...The effects of various amount of Y and La on the cast structure.the fluidity,the wearability and corrosion resistance of the high manganese aluminium bronze have been investigated.The results have shown that a proper content of rare earth elements is able to refine the cast structure of the alloy,and furthermore to enhance its wearability and corrosion resistance.The reasons for these phenomena have also been discussed.展开更多
Under aircondition,theinsitu TiCP/ Fecompositeshavebeen fabricated by a reactivecast ing route usingtheinexpensiveraw materials. The microstructuresofthecompositehavebeen studied by X ray diffraction,image analyz...Under aircondition,theinsitu TiCP/ Fecompositeshavebeen fabricated by a reactivecast ing route usingtheinexpensiveraw materials. The microstructuresofthecompositehavebeen studied by X ray diffraction,image analyzer and analyticalelectron microscopy. The me chanicalpropertiesand abrasive wearresistanceofboththeas castcompositeandthequenched composite havebeen measured. Theresultsshow thattheinsitu TiCparticles with a average sizeof 4 51μm exhibit a homogenous distribution inthe matrix, and an excellentinterface bonding between the particle and the matrix is achieved. As above microstructure features, thecomposite,especiallythequenched composite, hashigher mechanicalpropertiesand betterwear resistance,compared with high Cr whitecastiron.展开更多
The casting structure, chemical composition segregation, dendrite arm space,inclusiona and during the CSP (compact strip production) rolling process were investigated. Theresults show that the CSP thin slab has a feat...The casting structure, chemical composition segregation, dendrite arm space,inclusiona and during the CSP (compact strip production) rolling process were investigated. Theresults show that the CSP thin slab has a feature of uniform fine grains, more columnar crystals,less central porosity and segregation etc. There is no great difference in macrostructure betweenthe CSP thin slab and conventional slab; however, the fine dendrite structure of the CSP slab ismore uniform. Moreover, the central porosity and segregation are obviously improved after the firstpass; and the dendrite is bent along the rolling direction rather than broken into pieces. Smallinclusions with the diameter less than 10 mum in the CSP slab are dominantly consisted of aluminatesformed by Al deoxidation and Ca treatment and not floating out of the melt. The large sizeinclusions found in the continuous casting slab are very few.展开更多
基金This work was financially supported by the National Natural Science Foundation of China (No.50174028).
文摘Electric pulse modification （EPM） is a novel technique that reduces grain size by altering the structure of a melt. It was investigated that the response of the casting structure of high pure aluminum to EPM in different superheated melts. The results indicate that the grain refining effect of a given pulse electric field holds an optimal temperature range, moreover, a lower or higher superheated temperature will both disadvantage the improvements of casting structure. It essentially lies in the cooperative action between the distorted absorption of clusters and the activated capability of atoms in the aluminum melt.
文摘The effects of various amount of Y and La on the cast structure.the fluidity,the wearability and corrosion resistance of the high manganese aluminium bronze have been investigated.The results have shown that a proper content of rare earth elements is able to refine the cast structure of the alloy,and furthermore to enhance its wearability and corrosion resistance.The reasons for these phenomena have also been discussed.
文摘Under aircondition,theinsitu TiCP/ Fecompositeshavebeen fabricated by a reactivecast ing route usingtheinexpensiveraw materials. The microstructuresofthecompositehavebeen studied by X ray diffraction,image analyzer and analyticalelectron microscopy. The me chanicalpropertiesand abrasive wearresistanceofboththeas castcompositeandthequenched composite havebeen measured. Theresultsshow thattheinsitu TiCparticles with a average sizeof 4 51μm exhibit a homogenous distribution inthe matrix, and an excellentinterface bonding between the particle and the matrix is achieved. As above microstructure features, thecomposite,especiallythequenched composite, hashigher mechanicalpropertiesand betterwear resistance,compared with high Cr whitecastiron.
基金This work was financially supported by the National Natural Science Foundation of China (No. 50334010)
文摘The casting structure, chemical composition segregation, dendrite arm space,inclusiona and during the CSP (compact strip production) rolling process were investigated. Theresults show that the CSP thin slab has a feature of uniform fine grains, more columnar crystals,less central porosity and segregation etc. There is no great difference in macrostructure betweenthe CSP thin slab and conventional slab; however, the fine dendrite structure of the CSP slab ismore uniform. Moreover, the central porosity and segregation are obviously improved after the firstpass; and the dendrite is bent along the rolling direction rather than broken into pieces. Smallinclusions with the diameter less than 10 mum in the CSP slab are dominantly consisted of aluminatesformed by Al deoxidation and Ca treatment and not floating out of the melt. The large sizeinclusions found in the continuous casting slab are very few.
