扫描路径对激光立体成型GH3536合金组织与性能的影响

Effect of Scanning Path on Microstructure and Properties of GH3536 Alloy Fabricated by Laser Solid Forming

摘要:

GH3536合金是制造航空发动燃油喷嘴的主要材料。相比于传统的加工工艺，激光立体成形技术具有近净成形等优点，更适于生产结构复杂的结构件，降低成本。而扫描路径在激光立体成形过程中有至关重要的作用。本文采用金相、XRD、SEM、拉伸等检测手段探究45°交叉光栅式与往复交叉光栅式两种扫描路径对激光立体成形GH3536合金的影响。结果表明，两种扫描路径对成形后的GH3536合金显微组织影响不大。基体都是γ相，晶界有M23C6型碳化物，晶内既有M23C6型碳化物也有M6C碳化物的存在。往复交叉光栅式的热量累积稍高于45 °交叉光栅式，导致其孔隙率较大，高度较高。两种扫描路径的拉伸性能相近。断裂方式均为塑性断裂，裂纹发生在碳化物处，以沿晶断裂为主。

Abstract:

GH3536 alloy is the main material of aero engine fuel nozzle. Compared with the traditional processing technology, laser solid forming technology（LSF）has the advantages of near net forming, which is more suitable for the production of complex structural parts and reduces the cost. The scanning path plays an important role in LSF. In this paper, metallographic, XRD, SEM and tensile testing methods were used to explore the influence of 45° cross grating and zig-zag cross grating scanning paths on GH3536 alloy fabricated by LSF. The results show that the two scanning paths have little effect on the microstructure of GH3536 alloy fabricated by LSF. The substrate of two scanning paths are γ phase. There are M23C6 carbides in the grain boundary, and there are both M23C6 carbides and M6C carbides in the grain. The heat accumulation of zig-zag cross grating is slightly higher than that of 45 ° cross grating, resulting in larger porosity and higher forming height. The tensile properties of the two scanning paths are similar. The fracture mode is ductile fracture, and the crack occurs at the carbide, mainly transgranular fracture.