The effect of TiO 2/Al 2O 3 film on the properties of diamond and diamond/glass composites

A titania/alumina (TiO 2/Al 2O 3) film was coated on surface of diamond abrasive particles via a sol-gel technique. The effects of TiO 2/Al 2O 3 film on the properties of diamonds and diamond/glass composites were investigated. The results showed that the TiO 2/Al 2O 3 film could effectively improve the oxidation resistance of diamond, where the initial oxidation temperature of diamond was 600 °C in an air environment while oxidation of the TiO 2/Al 2O 3 film coated diamond could not be found below 775 °C. For a mechanical property investigation, the TiO 2/Al 2O 3 film coated diamond had a better compressive fracture strength (CFS) than that of the uncoated diamond after sintering. When the surface of a diamond was coated with a TiO 2/ Al 2O 3 film, the contact angle between liquid glass and diamond film decreased from 105° to 60 ° at 750 °C. For the application of the TiO 2/Al 2O 3 film coated diamond to diamond/glass composites, it was evident that the performance of the composites was improved.