GH3230合金TLP扩散焊工艺试验

针对航空发动机热端部件结构材料GH3230合金，设计并制造了2种TLP扩散焊用非晶态中间层，并开展了TLP扩散焊工艺试验。分析了非晶态中间层、保温时间和焊接温度对GH3230合金TLP扩散焊接头微观组织与力学性能的影响；分析了TLP扩散焊的焊接过程中组织和元素分布情况，确定了液相最大宽度和等温凝固完成需要的时间。结果表明，厚度0.025～0.035 mm表面光滑的2号中间层在几种工艺参数条件下均获得了较好的焊接质量，更加适合GH3230合金TLP扩散焊焊接；保温时间从2 h增加到8 h，等温凝固区缺陷不断减少，接头强度先升高后降低，保温4 h时强度达到最高；焊接温度从1 180 ℃升高到1 220 ℃，等温凝固区晶粒逐渐长大, 强度先增加后减少，1 200 ℃×4 h的条件下接头强度达到最高为887.68 MPa，为母材强度的97.6%，且弯曲90°后焊缝没有开裂。GH3230合金TLP扩散焊在保温2 h达到了最大液相宽度70 μm，等温凝固过程的完成时间在2～4 h之间。

Experiment on TLP diffusion welding of GH3230 alloy

Aiming at GH3230 alloy, the structural material of aeroengine hot end components, two kinds of amorphous interlayer for TLP diffusion welding were designed and manufactured, and experimental research on TLP diffusion welding process was carried out.Effects of amorphous interlayer, holding time and welding temperature on microstructure and mechanical properties of GH3230 alloy TLP diffusion welded joint were analyzed.Microstructure and element distribution during TLP diffusion welding were analyzed, and the maximum width of liquid phase and time required for isothermal solidification were determined.The results showed that No.2 interlayer with smooth surface and thickness of 0.025～0.035 mm obtained better welding quality under several process parameters, which was more suitable for TLP diffusion welding of GH3230 alloy.When holding time increased from 2 h to 8 h, defects in isothermal solidification zone continued to decrease, strength of joint first increased and then decreased, and strength reached the highest when holding time was 4 h.Welding temperature increased from 1 180 ℃ to 1 220 ℃, grains in isothermal solidification zone grew gradually, and strength increased first and then decreased, reaching maximum strength under the condition of 1 200 ℃ × 4 h, the maximum strength of joint was 887.68 MPa, which reached 97.6% of base metal, and weld did not crack after bending 90°.TLP diffusion welding of GH3230 alloy reached the maximum liquid phase width of 70 μm after holding for 2 h.Completion time of isothermal solidification process was between 2～4 h.