Characterization of the interfaces formed at the silicon nitride superalloy joints

Effect of Mo and W interlayers on microstructure and mechanical properties of Si3N4–nickel‐base superalloy joints

“…Cr could react with Si 3 N 4 to form chromium nitrides (CrN and Cr 2 N) and chromium silicides (CrSi 2 , Cr 3 Si, Cr 5 Si 3 ). Evidence of a few tens of nanometer thick reaction layers has been reported in Si 3 N 4 /Inconel‐718 joints made by a capacitor discharge technique that were subsequently heat‐treated 12 . Likewise, Ni from Inconel could form nickel silicides (NiSi, Ni 2 Si, NiSi 2 ).…”

“…Si 3 N 4 has been joined to steel, 7,8 aluminides, 3 tungsten (W), titanium (Ti), and niobium (Nb), 9,10 Ni‐base superalloys, 11–15 and other substrates using either direct bonding or in combinations of metal interlayers 16–18 . For example, multilayered Si 3 N 4 /steel joints have been brazed using AgCuTi brazes in conjunction with 2–4 mm thick Ni/W/Ni interlayers for applications such as turbocharger rotors with a Si 3 N 4 disc brazed to a steel shaft 1 …”

“…Additionally, active brazes, such as Pd-Ni-Ti, Au-Pd-Ti, Ni-Pd-Cr, Ni-Si-Cr, and Cu-Pt-Ti/Nb, and nonreactive brazes Pd-Ni and Au-Pd-Ni in conjunction with premetallized Si 3 N 4 also have been used. Si 3 N 4 has been joined to steel, 7,8 aluminides, 3 tungsten (W), titanium (Ti), and niobium (Nb), 9,10 Ni-base superalloys, [11][12][13][14][15] and other substrates using either direct bonding or in combinations of metal interlayers. [16][17][18] For example, multilayered Si 3 N 4 /steel joints have been brazed using AgCuTi brazes in conjunction with 2-4 mm thick Ni/W/Ni interlayers for applications such as turbocharger rotors with a Si 3 N 4 disc brazed to a steel shaft.…”

Unveiling the reaction products in heat treated Si3N4-Ti joined ceramics by transmission electron microscopy

“…At the same time, the 1000 kg compressive pressure was approximately applied to the sandwiched sample. The joining was completed in few micro seconds [28].…”

“…Nevertheless, especially main joining process techniques such as diffusion bonding, active metal brazing, and liquid phase bonding generally take long time, so it can alter the properties of the ceramic [24]. However, the capacitor discharge joining (CDJ) method [24][25][26][27][28] delivers a chance to investigate the preliminary reactions and phase formations. It is because CDJ is a very speedy technique and no necessity for a special atmosphere or heating.…”