UBC Theses and Dissertations
Influence of oxygen on the interfacial reaction between sapphire and copper. Misra, Surya Kumar
The influence of oxygen on the wetting of sapphire (α-Al₂O₃) by liquid copper was investigated using the sessile drop technique in vacuum at 1230°C. For additions to copper of cupric oxide, varying from 1 – 72% of the copper weight, chemical reaction at the liquid-solid interface resulted in spreading of the liquid and a rapid decrease of the contact angle to a steady state value. A direct relationship between the fourth power of the basal radius of the molten drop and the oxygen present was observed. The product of the interfacial reaction was found to be CuAlO₂. Phase diagrams of the systems CuO-Al₂O₃ and Cu₂O-Al₂O₃ were determined experimentally using X-ray diffraction techniques for identification of the phases. The aluminates, Cu(AlO₂)₂ and-CuAlO₂ were identified and their ranges of stability in air established.
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