摘要
采用分形理论定量地描述了定向凝固过程中固-液界面的形态,给出了固-液界面的分形维数与凝固速度、枝晶间距和试验合金中磷含量之间的关系发现随着凝固速率和合金中磷含量增大,固-液界面的分形线数呈指数规律增加。而且,结合分形理论和热力学理论论证了分形维数不仅仅是单纯描述不规则图形的几何参量,而且是一个依赖于凝固参数。
The statistically significant experimental technique was developed to investi-gate the directional solidification behavior of a nickel-base superalloy. This technique in-volves quantitative description of the rough level of the solid/liquid interface by means offractal analyses. The image analysis system technique was employed and the fractal dimensionof the solid / liquid interface of the test alloy was obtained. The relations among the fractal dimensions of the solid / liquid interface, solidification rate, dendrite arm spacing and thephosphorus content in the test alloys have been given. It was found that the increases of thesolidification rate and the phosphorus content in the test alloy will lead to increasing fractaldimension of the solid / liquid interface with index law. Furthermore, combining the fractaltheory and the thermodynamic principle with the measured results, it has been proved that thefractal dimension is far from simple geometrical parameter used in describing irregular geom-etry. It is a state function which depends on different physical parameters.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
1993年第3期A115-A120,共6页
Acta Metallurgica Sinica
基金
国家自然科学基金
关键词
分形维数
凝固速率
耐热合金
fractal dimension
solid/liquid interface
solidification rate
phosphorus
superalloy
