Spreading and interlayer formation at the copper-copper oxide/polycrystalline alumina interface

Ceramic-metal interfaces and the spreading of reactive liquids

“…An addition of oxygen to some metals dramatically enhances the wettability by changing the ceramic surface via a dissolution reaction and by lowering the surface tension of the liquid. [58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73][74] For example, for a liquid copper alloy in contact with alumina, the following dissolution reaction occurs:…”

“…However, copper-oxygen alloys have been used with considerable success to obtain continuous interfaces for alumina joining and alumina/copper composite processing. [58][59][60][61][62][63][64][65][66][67][68][69][70] For alumina brazing, shear fracture strengths of greater than 50 MPa have been obtained with oxidized copper interlayers. 61 In composite processing, pressure can also be used to force infiltration of a preform by a liquid metal that would normally not wet the preform material.…”

Transitions in Wetting Behavior Between Liquid Ag–CuO Alloys and Al2O3Substrates

“…The sessile drop/substrate interface in the 1100°C Ag–2 mol% CuO, Ag–3 mol% CuO and Ag–40 mol% CuO samples were additionally examined by removing the sessile drop from the substrate through a combination of careful grinding and subsequent dissolution in a continuously agitated nitric acid bath, similar to the method by Baldwin et al . The samples were evaluated using a stereographic optical microscope.…”

“…The current study investigates the wetting characteristics and microstructural features of a series of potential Ag–CuO filler metal compositions on a model reactive substrate material, alumina (Al 2 O 3 ). Prior work has shown that when Al 2 O 3 is exposed to liquid copper oxide at high temperature, an interfacial reaction product (copper aluminate) can form . In general, increasing the temperature, oxygen partial pressure, copper oxide content, or time at temperature will increase the quantity of copper aluminate produced.…”

Writing conducting lines into alumina ceramics by a laser dispersing process

“…The wettability of alumina at high temperatures by copper was investigated in many publications. 2,5 Without oxygen, no wetting between copper and alumina is possible. When using the same parameters as in the experiments with tungsten powder, only droplets of copper were produced with no continuous conductivity.…”