变能量激光选区熔化IN718镍基超合金的成形工艺及高温机械性能

发布时间：2018-02-26 13:24

  本文关键词： IN镍基超合金 变能量激光选区熔化 激光成形 致密度 表面质量 高温机械性能　出处：《光学精密工程》2015年06期 　论文类型：期刊论文

【摘要】：开展了基于激光选区熔化技术对IN718镍基超合金直接激光熔化成形的研究。将零件分为心部与轮廓区,通过改变激光线输入量进行选区熔化研究。首先,建立熔池内烧结的数值模型,改变激光线输入量,获得了激光线输入量对零件致密度的影响规律并观察了成形体中的组织生长。然后,增加轮廓部位扫描,改变激光线输入量与扫描顺序,获得其对零件表面质量的影响规律。最后,通过优化热处理工艺提高零件高温拉伸强度和高温持久性能。试验结果表明,在激光线输入量为300J/m时,成形体致密度最高,为98.9%,成形体沿层间方向组织为树枝晶加等轴晶,在层内方向组织为等轴晶。采用心部+后轮廓扫描的方式,轮廓激光线输入量为100J/m时表面质量最优,粗糙度为3.1μm。对成形体采用1 065℃固溶+双时效的热处理可以获得最佳高温性能组合,高温拉伸强度为1 356MPa,高温持久时间为34h。结果显示,通过激光选区熔化制作IN718镍基超合金可以满足航空结构件对致密度、表面质量和高温性能要求。
[Abstract]:The direct laser melting forming of IN718 nickel-based superalloy is studied based on laser selective melting technology. The parts are divided into the core and the contour region, and the selective melting is studied by changing the input amount of the laser line. The numerical model of sintering in the molten pool is established. The influence of laser line input on the density of the parts is obtained by changing the input amount of laser line, and the microstructure growth in the shape is observed. Then, the scanning of the profile is added. The influence of laser line input and scanning sequence on the surface quality of the parts is obtained. Finally, the tensile strength at high temperature and the high temperature rupture property of the parts are improved by optimizing the heat treatment process. The experimental results show that, When the input of the laser line is 300J / m, the density of the shape is 98.9, the shape is dendritic and equiaxed along the interlayer direction, and the equiaxed crystal is formed in the inner layer. The surface quality is the best and the roughness is 3.1 渭 m when the input amount of the contour laser line is 100 J / m. The best combination of high temperature properties can be obtained by heat treatment of solid solution double aging at 1 065 鈩，

本文编号：1538193