单晶过渡液相扩散焊接头单晶化机理

发布时间：2018-04-20 04:40

  本文选题：单晶 + 晶体取向　； 参考：《焊接学报》2017年01期

【摘要】：为了探明单晶高温合金TLP扩散焊接头单晶化机理,采用扫描电镜(SEM)、背散射电子(BES)和背散射衍射(EBSD)分析接头微观组织.结果表明,接头内形成贯穿型晶界和等轴晶粒是接头无法实现单晶化的主要原因.在实际焊接过程中,应严格控制试样加工、中间层添加、装配、焊接等工序.在等温凝固阶段,液相依附于固态单晶基体以平面晶的方式外延生长,直至液相消失,界面上形成具有一致晶体取向的一块单晶,随着保温时间的延长,固态均匀化过程充分进行,冷却后将形成单晶化的接头.
[Abstract]:In order to find out the mechanism of single crystal superalloy TLP diffusion welding joint, the microstructure of the joint was analyzed by means of scanning electron microscopy (SEM), back scattering electron beam (BES) and backscattering diffraction (EBSD). The results show that the formation of penetrating grain boundaries and equiaxed grains in the joints is the main reason for the failure of the joints to realize monocrystallization. In the actual welding process, the process of sample processing, interlayer addition, assembly and welding should be strictly controlled. At the stage of isothermal solidification, the liquid phase adheres to the solid single crystal matrix and epitaxially grows in the form of plane crystal, until the liquid phase disappears, and a single crystal with uniform crystal orientation is formed on the interface. With the prolongation of the holding time, The process of solid-state homogenization is fully carried out, and a single crystal joint will be formed after cooling.
【作者单位】： 北京航空制造工程研究所航空焊接与连接技术航空科技重点实验室;北京科技大学;
【分类号】：TG453.9
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本文编号：1776314