Preparation and characterization of sintered polycrystalline diamond (PCD) with 15 wt% Nb binder

• Published in: Diamond and related materials 2020-06, Vol.106, p.107867, Article 107867
• Main Authors: Barreto, L.P.P., Mashhadikarimi, M., Rodrigues, M.A.L.O., Gurgel, D.P., Gomes, U.U., Filgueira, M., Medeiros, R.B.D.
• Format: Article
• Language: English
• Subjects: Ball milling; Characterization; Electron micrographs; Graphitization; High temperature; HPHT sintering; Niobium; Polycrystalline diamond; Polycrystals; Sintering; Sintering (powder metallurgy); Spectrograms
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2020.107867

This study aimed to obtain and characterize a polycrystalline diamond body (PCD) sintered with 15 wt% Nb binder, through the high-pressure high-temperature (HPHT) sintering techniques at three different temperatures of 1650 °C, 1750 °C, and 1850 °C, with a pressure of 7.7 GPa. Characterizations on the starting powders were performed before and after high energy ball milling, and then the obtained mixture was sintered. The results showed that niobium could perform as a good binder for the sintering PCD at the specified concentration, achieving relative densities in the range of 96% to 100% for all three sintering temperatures. Also, analyses of the electron micrographs and the Raman spectrograms showed that there was no graphitization, a common problem in this type of material, and there was uniform dispersion of the niobium at the interfaces of the diamond particles, and no cracking. [Display omitted] •High energy milling was effective to mix particles and reduce their size.•HPHT sintering was a good route to produce this PCD in three temperatures.•Niobium proved to be a good binder, helping to prevent graphitization.•Samples sintered in all 3 temperatures had densities in the range of 96% to 100%.