Effect of Ti powder particle sizes and raw material ratio on properties of Ti-coated diamond powder

Abstract

ObjectivesTitanium plating on the surface of diamond powder can improve its wettability to the bonding agent, and the preparation process of the titanium-plated metal layer is of great significance to the industrial application of diamond powder. The effect of particle size and raw material ratio of Ti powder on the properties of Ti coated diamond powder is analyzed.MethodsDifferent particle sizes (60 mesh coarse powder, ~250 μm and 325 mesh fine powder, ~45 μm) and raw material ratios are compared, and so are the vacuum and protective atmosphere titanium plating process. The experiments involve diamond particles, fine titanium powder, and titanium powder. The materials are immersed in hydrochloric acid and washed twice with acetone. Four ratios (5:3, 2:1, 1:1, 1:2) are set based on the mass ratio of diamond and titanium powder. The materials are sintered under vacuum or Ar protective atmospheres, and the Ti powder slag and Ti-coated diamond particles are separated.ResultsThe chemical composition of titanium-coated diamond powders is characterized by XRD as diamond, Ti, and TiC transition layers. The morphology of titanium coated diamond powders and the distribution of elements on the surface are analyzed by SEM, which shows that Ti coating on the surface of diamond particles could be achieved with different ratios and Ti powder particle sizes. The Raman spectra of fine Ti-coated diamond contain characteristic peaks of diamond and Ti, while those of coarse Ti-coated diamond and Ti-coated diamond synthesized in a vacuum atmosphere are affected by the ratio of raw materials. The UV-visible absorption spectra show that there are obvious absorption peaks in the wavelength region of 228-234 nm and 328-350 nm for Ti-coated diamond, respectively. The weight loss rates of vacuum-synthesized titanium-coated diamond and fine-grained Ti-coated diamond are lower than those of coarse-grained Ti-coated diamond.ConclusionsCombined with the results of Raman spectra, ultraviolet absorption spectra, and thermal analyses, the performance of fine Ti-coated diamonds under argon atmosphere protection is better than that of coarse Ti powder-coated diamonds and vacuum atmosphere-coated diamonds.

Keywords

• abrasive coating technology
• diamond powder
• ti powder
• raman spectroscopy
• thermal analysis