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可以看出,铸件的组织受到三个主要影响: 1.合金成分金属的成分支配着结晶的基本模式,决定着组织是否由单相或共晶晶粒所组成,或二者兼有。溶质在液相和固相中有着特定的分配和扩散系数,这也是合金成分的特征,因而就形成了相对的成分过冷倾向,这就确定了相对成分过冷倾向的大小。 2.热条件铸件中的温度分布和冷却速度来源于金属和铸型的初始温度条件和热性质。 3.液体中固有的生核和成长条件生核和成长的相对可能性取决于液体中存在着的外
It can be seen that the microstructure of a casting is subject to three main effects: 1. Alloy composition The composition of the metal dictates the fundamental mode of crystallization that determines whether the microstructure consists of single-phase or eutectic grains, or both. Solute in the liquid and solid phase has a specific distribution and diffusion coefficient, which is the characteristics of the alloy composition, and thus formed a relative composition of the overcooling tendency, which determines the relative composition of the size of the overcooling tendency. 2. Thermal conditions The temperature distribution and cooling rate in castings come from the initial temperature conditions and thermal properties of the metals and molds. 3. Inherent Nucleation and Growth Conditions in Liquids The relative probability of nucleation and growth depends on the presence of liquid