As an advanced solid state bonding process, plastic deformation bonding (PDB) is a highly reliable metallurgical joining method that produces significant plastic deformation at the bonding interface of welded joints through thermo-mechanical coupling. In this study, PDB behavior of IN718 superalloy was systematically investigated by performing a series of isothermal compression tests at various processing conditions. It was revealed that new grains evolved in the bonding area through discontinuous dynamic recrystallization (DDRX) at 1000–1150 °C. Electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM) results revealed that the bonding of joints is related with interfacial grain boundary (IGB) bulging process, which is considered as a nucleation process of DRXed grain under different deformation environments. During recrystallization process, the bonded interface moved due to strain-induced boundary migration (SIBM) process. Stored energy difference (caused by accumulation of dislocations at the bonding interface) was the dominant factor for SIBM during DRX. The mechanical properties of the bonded joints were dependent upon the recrystallized microstructure and SIBM ensued during PDB.

作为一种先进的固态键合工艺，塑性变形键合（PDB）是一种高度可靠的冶金连接方法，它通过热机械耦合在焊接接头的键合界面处产生明显的塑性变形。在这项研究中，通过在各种加工条件下进行一系列等温压缩试验，系统地研究了IN718高温合金的PDB行为。结果表明，在1000-1150°C时，通过不连续动态重结晶（DDRX）在键合区域产生了新晶粒。电子背散射衍射（EBSD）和透射电子显微镜（TEM）结果表明，接头的结合与界面晶界（IGB）鼓胀过程有关，被认为是不同变形环境下DRX晶粒的成核过程。在重结晶过程中，键合界面由于应变诱发的边界迁移（SIBM）过程而移动。在DRX期间，SIBM的主要因素是存储的能量差（由键合界面处的位错积累引起）。粘结接头的机械性能取决于PDB期间的再结晶微结构和SIBM。