摘要 :
A theoretical analysis was presented to produce gradient composite by centrifugal casting.particle movement in liquid metal is described and gradient distribution of particles in com-posite is calculated in a centrifugal field.The...
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A theoretical analysis was presented to produce gradient composite by centrifugal casting.particle movement in liquid metal is described and gradient distribution of particles in com-posite is calculated in a centrifugal field.The factors affected the gradient distribution are discussed in detail .There exist composite zone and blank zone in(?)radient composite.whichwas proved by experiments. Finally,a theoretical analysis is given to explain the abovementioned particle distribution.
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摘要 :
The SiCp/(Al-Cu) alloy and pure Al matrix composites have been prepared by the centrifugal casting with electromagnetic stirring. There are two particle-depleted zones formed in the samples without electro-magnetic stirring.Electr...
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The SiCp/(Al-Cu) alloy and pure Al matrix composites have been prepared by the centrifugal casting with electromagnetic stirring. There are two particle-depleted zones formed in the samples without electro-magnetic stirring.Electromagnetic stirring may result in a homogeneous distribution of fine SiC particles in the Al-Cu alloy, whereas it has little effect on the segregation in pure Al matrix. The results also show that the particle segregation is influenced by particle size and the coarse particles are more readily segregated than the fine ones.
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摘要 :
Recently proposed mathematical model for mold filling processes under centrifugal force field conditions and the computer codes were first tested through the sample simulation of gravity mold filling process for a benchmark plate-...
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Recently proposed mathematical model for mold filling processes under centrifugal force field conditions and the computer codes were first tested through the sample simulation of gravity mold filling process for a benchmark plate-casting, which were compared with quoted experimental observations. The model and the developed computer program were then applied to the numerical simulation of centrifugal field mold filling processes for a thin-section casting with a titanium alloy melt of assumed viscosity of 1.2 and 12.0 mm2/s, respectively. The computation result comparison shows that the flow behaviors of the filling melts are basically similar to each other although the less viscous melt tends to fill into the thin section casting cavity faster.
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摘要 :
High speed steel (HSS) rolls can replace traditional rolls such as alloyed cast iron rolls and powder metallurgical (PM) hard alloy rolls. The main reasons for the replacement are that the wear resistance of low-cost alloyed cast ...
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High speed steel (HSS) rolls can replace traditional rolls such as alloyed cast iron rolls and powder metallurgical (PM) hard alloy rolls. The main reasons for the replacement are that the wear resistance of low-cost alloyed cast iron rolls is poor and the cost of high-quality PM hard alloy rolls is very high. By means of centrifugal casting, HSS rolls having excellent wear resistance have been manufactured. The hardness of the HSS roll is 65～ 67 HRC, the range of variation is smaller than 2 HRC and its impact toughness is 15 J/cm2. The wear rate of HSS rolls used in the pre-finishing stands of high-speed hot wire-rod rolling mill reaches 2.5 × 10-4 mm per ton steel. Furthermore, the manufacturing cost of HSS rolls is significantly lower than that of PM hard alloy rolls; it is only 30 percent of that of PM hard alloy rolls.
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摘要 :
In this research, Ti-15V-3Cr-3Al-3Sn alloy ingots were prepared using ceramic mold and centrifugal casting. The Ti-15V-3Cr-3Al-3Sn setting casting, for aeronautic engine, with 1.5 mm in thickness was manufactured.The alloy melting...
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In this research, Ti-15V-3Cr-3Al-3Sn alloy ingots were prepared using ceramic mold and centrifugal casting. The Ti-15V-3Cr-3Al-3Sn setting casting, for aeronautic engine, with 1.5 mm in thickness was manufactured.The alloy melting process, precision casting process, and problems in casting application were discussed. Effects of Hot Isostatic Pressing and heat treatment on the mechanical properties and microstructure of the Ti-15V-3Cr-3Al-3Sn alloy were studied.
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摘要 :
Centrifugal slip casting in prefabricated template was used to prepare open-cell Al2O3 foams. Aqueous α- Al2O3 slurries with up to 50% solid contents (volume fraction) were prepared. The sedimentation of slurries during centrifug...
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Centrifugal slip casting in prefabricated template was used to prepare open-cell Al2O3 foams. Aqueous α- Al2O3 slurries with up to 50% solid contents (volume fraction) were prepared. The sedimentation of slurries during centrifugation was discussed with respect to the hydronamic conditions at large particle concentrations. The effect of solid contents on mass segregation was observed. Segregation phenomena were hindered for slurries with high solid loadings exceeding 50% ( volume fraction). The dried and sintered behaviors of samples were analyzed. The cell struts in green bodies had good particles packing and showed high green density ( 63.4% theory density ). After sintered at 1500 ℃, the cell struts of final products had high sintered density ( 98. 8% theory density) and homogeneous microstructure. The porosity of final products is 75.6%
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摘要 :
Navier-Stokes equation and Lorentz force equation are used to calculate the fluid field of liquid metal of electromagnetic centrifugal casting(EMCC) in this paper.A field equationis given,which shows the azimuthal velocity closely...
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Navier-Stokes equation and Lorentz force equation are used to calculate the fluid field of liquid metal of electromagnetic centrifugal casting(EMCC) in this paper.A field equationis given,which shows the azimuthal velocity closely relates to electrical conductivity,mag-netic density,viscosity of liquid metal and radius of casting.The results show that the sta-tionary magentic field can effectively restrain the fluid flow and the relative velocity be-tween liquid metal and casting mould and the velocity gradient at solid/liquid interface in-creases with rising magnetic density,which has a great effect on the solidification of liquidmetal and crystal growth characteristies.
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