Microstructural evolution during the brazing of Al 2 O 3 ceramic to kovar alloy by sputtering Ti/Mo films on the ceramic surface

Microstructure Evolution and Mechanical Properties of Titanium/Alumina Brazed Joints for Medical Implants

“…It was notable that the TiAu4 layer almost occupied the brazing seam next to the ceramic (Figure 7e). It has been widely reported that TiOx could be generated on the interface of Ti containing metal and Al2O3 [25,30,32,35,[38][39][40]. The limited thickness of TiOx and many other compounds in metalceramic interfaces led to a decreased accuracy in the identification of titanium oxides [20,44].…”

“…It has been widely reported that alumina could be brazed to different metals with Ti-containing filler alloys [10,21,[32][33][34][35][36][37]. The types of titanium oxides that form in an Al 2 O 3 /Kovar joint using Ag-Pd/Ti filler are found to be affected by the thickness of the Ti layer, and the joint strengths are influenced by the thicknesses of the reaction layer and residual Ti layer [32].…”

“…For test temperatures higher than 1057 • C, Ti directly reacts with O from Al 2 O 3 to generate TiO and Ti 3 Al [10]. Simultaneously, the type of Ti oxide depends on the activity of Ti in the reaction layer, which could be decreased by the interaction between Ti and Ni from Kovar substrate to form Ni 3 Ti, resulting in a shift of reaction product from TiO to Ti 2 O 3 or Ti 3 O 5 [35]. This is also observed by other investigations [38][39][40].…”

Surface resistivity and bonding strength of atmosphere plasma sprayed copper‐coated alumina substrate

“…4 Currently used methods of metallic coatings on ceramics include Mo-Mn method, 5,6 activity metal blazing (AMB), 7,8 direct bonded copper (DBC), 9,10 and direct plating copper (DPC). 11,12 The advantage feature of these methods is that an adhesive interlayer can be produced between alumina substrate and metal films. Unfortunately, with drawbacks such as residual stress resulting from high-temperature process, costly equipment, and sophisticated handle procedure, products manufactured by these methods are not suitable for the high integrated circuit.…”

Brazing of SiC ceramics pretreated by chromium coating using inactive AgCu filler metal

“…Electroless plating of nickel was introduced to metallized on quartz fibers reinforced silica composites to assist its brazing to Invar alloy using AgCu eutectic alloy, the maximum shear strength of joint is 29 MPa when brazed at 1103 K for 15 minutes 27 . Researchers 28 introduced Ti/Mo bilayer films on alumina ceramics, then metalized at high temperature, which achieved the brazing to Kovar alloy using inactive AgCu eutectic alloy successfully, and the joining strength is related to the thickness of the Ti/Mo layer. In our previous study, 22 coating chromium on graphite surface could effectively enhance the wettability of inactive AgCu filler metal on substrates and achieve reliable joining of graphite.…”