Li Yongjun, Li Sicheng, Lu Ran, Qin Jiaqian, Zhang Jian, Wang Jianghua,
Wang Fulong, Kou Zili, He Duanwei
(Institute of Atomic and Molecular Physics, Sichuan University, 610065)
Abstract Cubic boron nitride (cBN) composites starting with cBN-Al mixtures were sintered on WC-16 wt.% Co substrates under static high pressure of 5.0 GPa and at temperatures of 800 to 1 400 ℃ for 30 minutes. Vickers hardness of the sintered samples increased with increasing cBN content and the highest hardness of 32.7 GPa was achieved for the cBN-5 wt.% Al specimens sintered at 1 400 ℃. The reactions between cBN and Al started to occur at about 900℃ and the reaction products strongly depended on the Al content, sintering temperature and Co diffused from the substrates according to the x-ray diffraction (XRD) observations. The cBN composite sintered at 1 200 ℃ from a cBN-15 wt.% Al mixture showed the best cutting performance.
Keywords cubic boron nitride; high pressure and high temperature; sintering.