Common Mechanical Properties of Diffusion Bonded Joints and Their Corresponding Microstructure Features

Microstructural Evolution in Nonvacuum Solid-State Diffusion Bonded Joints of AA2219

“…When the bonding temperature further increased to 475 °C, the voids are crushed to form a hardly visible bond line, and the grain growth occurred across the interface, which is represented in Figures 8(a) and 8(b). Te sections bonded at 475 °C also exhibit minute voids, infrequently at some parts of the interface and thin precipitations persist on the bond line as shown in the detailed view in Figure 8(b), which are certainly the main causing factors for the incomplete grain growth across the interface [37]. At a bonding temperature of 500 °C, however, a complete grain development across the interface by producing a single homogeneous structure is achieved, which is shown in Figure 9.…”

“…Te points at the center show (Figure 15) a maximum hardness of 112.14 Hv, whereas hardness has been reduced while testing on the points away from the center. Te changes in hardness values at the interface are mainly due to the sound joint formed by the coarsening of precipitates with the increase in temperature at the bonded zone [37] whereas a similar difusion bonding study conducted in an inert atmosphere reported approximately the same hardness value at the interface and base materials [25].…”

Creep Behavior of Diffusion-Welded Alloy 617

“…The discrete Al-rich oxides along the interface restricted grain-boundary movement, leaving a planar grain boundary. Some researchers have emphasized that the evolution of stable surface oxides (film or discrete type) is a governing factor limiting metal-to-metal joining [34,36,38,39,[50][51][52][53][54].…”

“…Diffusion welding without the application of interlayers seems to be an alternative solution [30][31][32][33][34][35][36][37][38][39] and pressure on joint quality [30]; they achieved a tensile strength comparable to that of the parent metal at room temperature. Shirzadi and Wallach proposed a fascinating method to remove surface oxides that inhibit metal-to-metal joints of superalloys [31].…”

“…Song et al evaluated the bonding performance by measuring the thermal/mechanical properties and conducting pressure-resistance tests [37]. Xiong et al reported a comprehensive review of the mechanical properties and their corresponding microstructural features [38]. Recently, Sah et al provided reasonable evidence for grain-boundary movement at the interface [39]; they emphasized the control of micro-chemistry at or near the surface to be bonded to obtain a precipitate-free interface.…”