Xingqiu CHEN
,
Hailan LI
,
Xueyong DING
,
P.Rogl
,
P.Podloucky
材料科学技术（英文）
The improved form of calculation formula for the activities of the components in binary liquids and solid alloys has been derived based on the free volume theory considering excess entropy and Miedema's model for calculating the formation heat of binary alloys. A calculation method of excess thermodynamic functions for binary alloys, the formulas of integral molar excess properties and partial molar excess properties for solid ordered or disordered binary alloys have been developed. The calculated results are in good agreement with the experimental values.
关键词:
Binary alloy
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null
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null
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null
A.Cantarel
,
E.Lacoste
,
O.Mantaux
,
E.Arquis
,
M.Danis
材料科学技术（英文）
Injection of liquid alloy through a fibrous preform located in an initially preheated mould is a classical method used to process metal matrix composites (MMCs). In order to reduce the chemical reactions between the fibres and the metal matrix, the fibrous reinforcement and the mould are commonly preheated up to initial temperatures much lower than the metal solidification temperature. Therefore, metal solidification instantaneously occurs on fibre contact during composites infiltration. Unlike what happens when infiltrating a pure metal, temperature and composition are able to vary within the matrix; these heterogeneities induce macrosegregation within composites...
关键词:
Segregation
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null
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null
Hua HOU
,
Dong-Ying Ju
,
Yuhong ZHAO
,
Jun CHENG
材料科学技术（英文）
Two-dimensional numerical simulation for the dendrite growth of binary alloy during solidification is carried out by a phase field method. In the model equations, phase field, temperature and solute redistribution are all involved. The equations are solved using the finite difference method (FDM) with two different space steps of phase field and temperature field. In calculation, the thermal noise is introduced to generate the side branches; the dependence of dendrite growth on the space step was also investigated. It is shown that thermal noise can trigger the growth of side-branches, however it has no influence on the stable behavior of the dendrite tip; the feature of dendrite growth is reasonable with δ Δx≤0.6W0, Δx is the space step and W0 is the thickness of interface.
关键词:
Phase field
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null
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null
