Controlled oxidation of copper coatings on the surfaces of diamond particles

In order to improve the wettability of molten glass on diamond particles, copper coatings on the surfaces of diamond particles should be oxidized in certain atmosphere to obtain Cu₂O coatings with eertain thickness. Thermodynamic calculations for the oxidation of copper coatings on diamond surfaces were carried out and the oxidation process was determined to be proceeded at 650℃ in N₂/H₂O atmosphere with a dew point of 20℃. The dynamic research results showed that the oxidation of copper coatings on diamond surfaees followed a parabolic rule and the parabolic rate constant was 1.127 5 ×10^-12g²·cm^-4·min^-1 in this condition. On this base, the oxidation time was chosen as 40 min. XRD results showed that the oxidized copper coatings on the surfaces of diamond partides were only composed of Cu and Cu₂O, without any CuO.