激光与光电子学进展, 2017, 54 (7): 071402, 网络出版: 2017-07-05
选区激光熔化镍基单晶高温合金的熔池显微组织 下载: 517次
Molten Pool Microstructure of Ni-Based Single Crystal Superalloys Fabricated by Selective Laser Melting
激光技术 选区激光熔化 熔池显微组织 镍基单晶高温合金 laser technique selective laser melting microstructure of molten pool Ni-based single crystal superalloy
摘要
根据柱状晶向等轴晶转变(CET)图,建立了激光熔池横截面的几何关系,得出了选区激光熔化(SLM)镍基单晶高温合金的凝固条件与显微组织的关系,并在SRR99单晶基板的(100)晶面上沿[001]方向进行了SLM实验。结果表明,当激光功率为160 W、铺粉层厚为20 μm、扫描速率Vb≤30 m·min-1时,凝固速度与激光扫描速度的夹角最小值为46.4°(大于45°)。可以预测激光熔池组织仅由熔池底部向顶部生长的[001]枝晶和熔池两侧的[010]枝晶组成,实验结果与理论分析结果相吻合,且层间形成了良好的冶金结合,基层的结晶取向得到延续。
Abstract
Based on the columnar to equiaxed transition (CET) map, the geometrical relationship for the cross section of the molten pool is established and the relationship between the solidification condition and the microstructure for Ni-based single crystal superalloys fabricated by selective laser melting (SLM) is obtained. The SLM experiments are conducted on the (100) crystallographic plane of SRR99 single crystal substrate along the [001] direction. The results show that the minimum angle between the solidification velocity and the laser scanning velocity is about 46.4° (larger than 45°) under the conditions of laser power of 160 W, powder-layer thickness of 20 μm and scanning speed of Vb≤30 m·min-1. It can be predicted that the microstructure of the laser molten pool is composed of [001] dendritic crystals growing from bottom to top and [010] dendritic crystals on two sides. The experimental results coincide well with the theoretical analysis results. In addition, good metallurgical bonds are formed between layers and the crystallographic orientation of substrates gets extended.
潘爱琼, 张辉, 王泽敏. 选区激光熔化镍基单晶高温合金的熔池显微组织[J]. 激光与光电子学进展, 2017, 54(7): 071402. Pan Aiqiong, Zhang Hui, Wang Zemin. Molten Pool Microstructure of Ni-Based Single Crystal Superalloys Fabricated by Selective Laser Melting[J]. Laser & Optoelectronics Progress, 2017, 54(7): 071402.