论文部分内容阅读
针对“光束中空,光内送粉”的激光熔覆工艺方法,利用Ansys软件的参数化设计语言(APDL)建立了环形激光光斑连续移动加载的激光熔覆模型。通过计算该模型,可以掌握环形激光光内送粉激光熔覆过程中温度场的分布规律。计算结果表明,采用环形激光束加载时,熔池的最高温度区域的形状呈现出“马鞍形”。在基体纵切面上,熔池的高温区域分布呈不对称的“W”形,且高温区域主要分布在光斑中心往后;在基体横截面上,熔池的高温区域分布呈对称的“W”形,熔池中心温度低,两侧温度高,通过基体横断面等温线的分布能够判断熔覆层与基体的结合情况。位于扫描路径中心位置的点在激光束扫过其过程中会经历迅速升温、降温、升温、再迅速降温的急冷急热过程,且第二次升温高于第一次的温度值;位于光斑内外环之间的点在激光束扫过其过程中只有一次升温降温的过程,温度分布较均匀。
Aiming at the “laser cladding process” of “beam hollow and light feeding”, the laser cladding model of continuous laser beam loading was established by using Ansys software’s parametric design language (APDL). By calculating this model, we can know the distribution law of the temperature field in the process of powder laser cladding in the ring laser light. The calculation results show that the shape of the highest temperature region of the molten pool presents a “saddle shape” when loaded with a circular laser beam. In the longitudinal section of the substrate, the distribution of the hot zone in the molten pool is asymmetric and the high temperature region is mainly distributed behind the center of the spot. In the cross section of the substrate, the distribution of the hot zone in the bath is symmetrical. “W” shape, the center of the pool temperature is low, both sides of the high temperature, through the distribution of the substrate cross-sectional isotherms can determine the combination of the cladding layer and the substrate. The point located at the center of the scan path will undergo rapid quenching and rapid heating which is rapidly warmed, cooled, warmed and then rapidly cooled down while the laser beam is sweeping through it. The second temperature rise is higher than the first temperature; The point between the rings swept the laser beam in the process of heating and cooling only once, the temperature distribution is more uniform.