Inconel718高温合金多层夹芯板结构的LBW/SPF技术

Multi-sheet Sandwich Structure of Inconel718 Superalloy Manufactured by LBW/SPF Technology

Inconel718高温合金多层夹心板结构具有高强度、高刚度、轻量化结构的特点,已用于低成本、轻质火箭发动机的制造.采用LBW/SPF技术制造了Inconel718合金多层夹芯结构件,并对其超塑成形前后的微观组织进行了分析.试验结果表明:超细晶Inconel718合金板材具有优良的超塑性能,在T=950℃,初始应变速率为1.6×10-4/s的条件下,延伸率达到483.6%.LBW/SPF技术制造出的Inconel718高温合金多层夹芯构件具有外观形状良好、壁厚分布均匀等特点.面板与芯板激光焊接参数为:功率1050W,焊接速度1000mm/min,离焦量-0.80mm,保护气体流量0.6L/min;芯板与芯板激光焊接参数为:功率900W,焊接速度1000mm/min,离焦量-1.00mm,保护气体流量0.6L/min.多层夹芯板结构的超塑成形参数为:成形温度Tf=965℃;成形压力Pf=4.2MPa;成形时间tf=130min.微观组织分析表明超塑成形过程利于焊缝显微组织的改善并且能够提高其力学性能.因此,LBW/SPF技术适用于超细晶Inconel718高温合金多层夹芯结构的制造.

Multi-sheet sandwich structure of Inconel718 superalloy will be widely used for low-cost, lightweight rocket engine manufacturing due to its lightweight, high strength and stiffness. Multi- sheet sandwich structure of Inconel718 superalloy was manufactured by LBW/SPF（ laser beam welding/superplastic forming） technology. Test results showed： Superplasticity of Inconel718 superalloy was investigated. Under T = 950℃ and initial strain rate with k = 1.6 × 10 ^-4/s, the elongation of Inconel718 superalloy was 483. 6%. The multi-sheet sandwich structure manufactured by laser LBW/SPF technology had good shape, uniform wall thickness distribution. The laser penetration welding parameters of face plate and core plate were as follows ： Power 1050W, welding speed 1000mm/min, defocusing amount - 0.80mm, shield gas flow 0. 6L/min. The laser penetration welding parameters between the core plates were as follows：Power 900W, welding speed 1000mm/min, defocusing amount - 1. 00mm, shield gas flow 0. 6L/min. The parameters for superplastic forming were as follows： temperature T/ = 965℃, pressure P： = 4.2MPa,time t： = 130min. Superplastic forming process was favorable to improving the microstructure and mechanical properties of laser welding joints. Accordingly, LBW/SPF technology is an appropriate forming technology for multi-sheet sandwich structure of Inconel718 superalloy.