Study on laser beam welding/superplastic forming technology of multi-sheet cylinder sandwich structure for Inconel718 superalloy with ultra-fine grains
Study on laser beam welding/superplastic forming technology of multi-sheet cylinder sandwich structure for Inconel718 superalloy with ultra-fine grains
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DOI：
10.1016/j.matdes.2012.02.002
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发表时间：
2012-08-01
影响因子：
8.4
通讯作者：
Zhang, K. F.
中科院分区：
文献类型：
--
作者：
Qu, F. S.;Lu, Z.;Zhang, K. F.
Multi-sheet cylinder sandwich structure of Inconel718 superalloy will be widely used in aerospace as heat resisting and heat shielding structure due to its lightweight, high strength and stiffness. Superplasticity of Inconel718 superalloy was investigated. Under T = 950 degrees C and initial strain rate with (epsilon) over dot = 1.6 x 10(-4) s(-1), the elongation of Inconel718 superalloy is 483.6%. The perfect superplastic forming temperature for Inconel718 superalloy is at 950 degrees C. The laser penetration welding parameters are as follows: power 1200 W, welding speed 1200 mm/min, defocusing amount -1 mm, shield gas flow 0.6 L/min, and the parameters for superplastic forming are as follows: temperature T-f = 950 degrees C, pressure P-f = 4.2 MPa, time t(f) = 130 min. The multi-sheet cylinder sandwich structure manufactured by laser beam welding/superplastic forming (LBW/SPF) technology has good shape, uniform wall thickness distribution, high symmetry in internal structure. Laves phase, harmful to the materials, translates to the delta phase which will help improve the performance of the material after SPF process. The hardness of laser welding joints is improved from 331.63 HV to 391.74 HV after the SPF process. The tensile strength of base material of multi-sheet cylinder sandwich structure has been increased about 261 MPa after the SPF process. (C) 2012 Elsevier Ltd. All rights reserved.
