论文部分内容阅读
计算机模拟技术为凝固组织选择形态的研究提供了强有力的手段。本文对 Co—Cr—C 合金系在激光重熔条件下γ—Co 与 Cr_(7-x)Co_xC_3共晶生长形态选择过程进行了模拟实验;提出了基本假设并认为在可能存在的各种生长形态中先导相生长前沿界面应具有最高温度或最低过冷度;依此建立相应的数模系统进行研究。对该合金系激光重熔时凝固组织生长形态选择演绎过程的模拟实验研究表明,Co—Cr—C 合金系存在着朝碳化物倾斜的γ—Co 与 Cr_(7-x)Co_xC_3共晶生长区。伪二元共晶合金在足够过冷条件时会在激光熔池中出现树枝晶形态的初生γ—Co 组织,并且共晶生长形态区将延伸到相当宽的过共晶合金成分区内。这些计算机模拟结果得到了激光重熔实验的证实。
Computer simulation technology provides a powerful tool for the study of coagulation tissue selection morphology. In this paper, we simulated the growth process of γ-Co and Cr_ (7-x) Co_xC_3 eutectic in the Co-Cr-C alloy under laser remelting conditions. The basic assumptions were proposed and considered as possible in various growths In the morphology, the leading phase growth front interface should have the highest temperature or the lowest degree of undercooling; accordingly, a corresponding numerical system is established. Simulation experiments on the selective evolution of the solidified microstructure during laser remelting showed that the co-crystal growth regions of γ-Co and Cr_ (7-x) Co_xC_3 tilted toward the carbide in the Co-Cr-C alloy . The pseudo-binary eutectic alloy appears dendritic primary γ-Co microstructure in the laser pool when the temperature is sufficiently high and the eutectic growth morphology extends to a rather wide area of the hypereutectic alloy composition. These computer simulation results have been confirmed by laser remelting experiments.