摘要
利用 5k W CO2 激光器对 Al- 5.6wt% Mn合金进行了一系列表面重熔实验 ,并对熔池的形貌和微观组织进行了分析研究。实验结果表明 :重熔区组织较基体组织大大细化 ;随着生长速度的增大 ,重熔区组织由 Al6Mn枝晶向 α(Al) +Al6Mn共晶、α(Al)胞 /枝晶及完全无偏析固溶体转变 ,并对其形成原因进行了分析。熔池中存在的对流和激光扫描过程中工作台运动的不稳定造成了熔池表面波纹状组织和熔池中三维条带状组织的出现。
This is a progress report of a project funded by NNSFC(National Natural Science Foundation of China). We carried out laser remelting experiments of Al-5.6wt% Mn alloy with a 5kW CO_2 laser. We investigatied the surface characteristics and the microstructure in laser melted pool. We observed two new phenomena: (1) With increasing growth rate, the microstructure changes from Al_6Mn dendrite to α(Al)+Al_6Mn eutectic, then to α(Al) cellualr/dendrite, and finally to segregation-free solid solution. (2) Two kinds of banded structure caused by convection and unstable moving of the worktable have been observed on the surface of the molten pool and in the melted region.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
2001年第1期93-96,共4页
Journal of Northwestern Polytechnical University
基金
国家自然科学基金! (5 97710 5 4)
高校博士学科专项基金! (2 7)
