Fe314合金粉末激光快速成形组织与力学性能分析

Analysis of Mechanical Properties and Microstructures of Laser Rapid Forming Components with Fe314 Alloy Powders

利用Fe314合金粉末在45#钢基体上激光快速成形(LRF)出立体构件,揭示了快速成形的内部层间分布结构,观察了不同成形区域的金相组织,并分析了成形件的力学性能。结果显示,在组织方面,成形体内部各层呈梯子形交错叠加分布,晶体组织以细小致密的等轴晶为主,在底部分布着少量平面晶和粗大柱状晶;在力学性能方面,由于成形体组成相为奥氏体,故整体硬度较低,但塑性、韧性较好。在内部最大残余应力690MPa情况下未出现微裂纹,表明利用Fe314合金粉末激光快速成形的构件具有良好的抗开裂性能。

A component is fabricated with Fe314 alloy powders on the substrate of 45# steels. The interlaminar distributing structures,the microstructure in different regions and mechanical properties of components are investigated. It is indicated that forming layers are stacked up like ladder shapes in aspect of microstructures which are mainly constituted of tiny compact equiaxed grains with distribution of some flat grains and columnar grains on the substrate. Furthermore,the hardness of components is low accompanied with high plasticity and ductility in aspect of mechanical properties because of the composing phases of austenite. There is no appearance of cracks under 690 MPa maximum residual stress,which has shown a high crack resistance is obtained through laser rapid forming （LRF） with Fe314 alloy powders.