GH4169高温合金TLP扩散焊接头组织性能研究

发布时间：2018-03-15 12:16

本文选题：GH4169　切入点：TLP　出处：《山东大学》2017年硕士论文　论文类型：学位论文

【摘要】：针对目前GH4169镍基高温合金在航空航天领域的广泛使用,同时结合瞬时液相扩散焊(TLP)的发展现状,本文对传统GH4169瞬时液相扩散焊工艺进行优化改良,使用45μm箔片状BNi-2中间层材料,通过使用所设计的三种瞬时液相扩散焊工艺:等温等压扩散工艺、降温升压扩散工艺、升温降压扩散工艺,对使用这三种不同焊接工艺连接的接头进行接头组织及力学性能的研究,并提供了工艺优化的方向和依据。具体分析了三种TLP扩散焊工艺焊接接头等温凝固区(ISZ)中存在的一类析出物的形貌特征、析出量和析出位置,扩散区(DZ)中存在的一类三种形貌析出物的形貌特征和析出位置,并通过扫描电镜(SEM)配合能谱仪(EDS)分析析出物的元素组成,比较了三种TLP扩散焊工艺焊接接头ISZ、DZ的宽度尺寸、接头母材区晶粒度、硬度差异,通过室温拉伸试验分析工艺-组织-力学性能三者的联系性。通过使用SEM、EDS、XRD、OM确定接头拉伸试验拉伸断裂位置,指出接头强度的薄弱位置。最后,通过优化TLP扩散焊连接工艺曲线,对等温等压扩散工艺进行不同焊接压力的实验,指出一定压力范围内焊接压力对等温等压扩散工艺接头组织性能的影响,对降温升压扩散工艺进行不同等温凝固时间的实验,指出等温凝固时间增加对接头组织性能不利的影响,同时分析降温升压扩散工艺接头ISZ的特殊形态的析出物,指出其产生原因,以及其对接头性能的不良影响,确定了工艺优化,参数选择的原则。
[Abstract]:In view of the wide application of GH4169 nickel based superalloy in aerospace field and the development of transient liquid phase diffusion welding (TLPP), the conventional GH4169 transient liquid phase diffusion welding process is optimized and improved, and 45 渭 m foil sheet BNi-2 interlayer material is used. By using three kinds of instantaneous liquid phase diffusion welding technology: isothermal and isobaric diffusion process, temperature drop and pressure rise diffusion process, temperature and pressure reduction diffusion process, The microstructure and mechanical properties of the joints connected by these three different welding processes were studied. The direction and basis of process optimization are provided. The morphology, amount and location of a class of precipitates in the isothermal solidification zone of three TLP diffusion welding processes are analyzed in detail. The morphologies and locations of three kinds of precipitates in diffusion zone (DZ) were analyzed by scanning electron microscopy (SEM) and energy spectrometer (EDS). The width and size of the welded joints in three TLP diffusion welding processes were compared. The difference of grain size and hardness in the base metal area of the joint is analyzed by the tensile test at room temperature. The connection between the workmanship, the microstructure and the mechanical properties is analyzed. The tensile fracture position of the joint is determined by means of SEMMA-EDSX XRDX OM, and the weak position of the joint strength is pointed out. By optimizing the joining process curve of TLP diffusion welding, the different welding pressure of isothermal isobaric diffusion process is tested, and the effect of welding pressure on the microstructure and properties of isothermal isobaric diffusion process joint is pointed out in a certain pressure range. Experiments on different isothermal solidification time were carried out in the process of cooling and boosting diffusion. It was pointed out that the increase of isothermal solidification time had an adverse effect on the microstructure and properties of the joint. At the same time, the precipitates of the special form of ISZ of the joint were analyzed. The causes and adverse effects on the properties of joints are pointed out, and the principles of process optimization and parameter selection are determined.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG453.9

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