SP700/TC4钛合金蜂窝夹层结构钎焊工艺分析

Analysis on SP700/TC4 titanium alloy honeycomb sandwich brazing

关键词:  SP700钛合金  蜂窝夹层结构  钎焊

Key words:  SP700 titanium alloy  honeycomb sandwich construction  brazing

摘要:

采用非晶态Ti-Zr-Cu-Ni箔带钎料对SP700/TC4钛合金蜂窝结构进行钎焊工艺研究，分析了钎焊温度和保温时间对钎焊接头组织和力学性能的影响. 结果表明，当钎焊温度在875～890 ℃之间变化时，随温度升高，钎焊接头中元素扩散更为充分，接头拉脱强度持续增长；在890 ℃下保温2～4 h不同时长进行钎焊，接头的拉脱强度先逐渐增加，在保温时间为3.5 h时达到最大值，随后逐渐降低. 获得SP700/TC4钛合金蜂窝结构的较优钎焊工艺为890 ℃/3.5 h，该工艺下钎焊接头的室温拉脱强度、三点弯曲强度、平面压缩强度、L及W方向抗剪强度分别达到14.64，224.05，11.21，4.43及3.76 MPa，破坏部位均为TC4蜂窝芯.

Abstract:

SP700/TC4 titanium alloy honeycomb sandwich construction is brazed by amorphous foil solder Ti-Zr-Cu-Ni. The effect of brazing temperature and holding time on microstructure of brazing interface and mechanical property has been researched. The results show that when the brazing temperature varies in the range from 875 ℃ to 890 ℃，with the increasing of the temperature, diffusion of the elements as well as the tensile strength of the weld could be better. When brazed at 890 ℃ with the holding time ranging from 2 h to 4 h, the tensile strength of the weld increases at first, and reaches the optimum with 3.5 h holding time, then decreases gradually. The optimized brazing technology is 890 ℃/3.5 h, with which the average tensile strength, three point bending strength, compression strength and L/W shear strength are 14.64, 224.05, 11.21, 4.43 and 3.76 MPa respectively, and the weak part is TC4 honeycomb core.