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研究了Cu-Pb偏晶合金的急冷快速凝固和组织形成规律,并通过将金属熔体的热传导方程和Navier-Stokes方程相耦合,理论分析了合金熔体的冷却速率、液固相变时间等物理参量与液相分离之间的相关性.研究结果表明,在急冷快速凝固条件下,熔体的快速冷却对偏晶合金组织形成的影响要比熔体内部液相流动的影响更为显著.快速凝固使液相分离受到抑制,Cu-Pb偏晶合金均可获得均匀的微观组织结构.随着冷速的增大,晶粒尺寸明显减小,凝固组织显著细化,晶体形态由粗大枝晶向均匀细小的等轴晶过渡.提高冷却速率,缩短液固相变时间是重力场中抑制液相分离、获得均匀偏晶组织结构的重要条件.
The rapid solidification and microstructure of Cu-Pb orthorhombic alloy were studied. By coupling the heat conduction equation of metal melt and Navier-Stokes equation, the cooling rate, liquid-solid phase transition time The correlation between the physical parameters and the liquid phase separation was studied.The results show that the rapid cooling of the melt affects the formation of the as-spit alloy more rapidly than the melt flow in the rapid solidification. The rapid solidification results in the suppression of liquid phase separation and the uniform microstructure of Cu-Pb amorphous alloy can be obtained.With the increase of cooling rate, the grain size decreases obviously and the solidified microstructure is refined remarkably, Crystal uniform and small equiaxed crystal transition.Improve the cooling rate and shorten the liquid-solid phase transition time is gravitational field inhibition of liquid phase separation, to obtain a uniform amorphous structure of the important conditions.