中国物理B ›› 2018, Vol. 27 ›› Issue (5): 56105-056105.doi: 10.1088/1674-1056/27/5/056105

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Polycrystalline cubic boron nitride prepared with cubic-hexagonal boron nitride under high pressure and high temperature

Ming Yang(杨鸣), Zi-Li Kou(寇自力), Teng Liu(刘腾), Jing-Rui Lu(卢景瑞), Fang-Ming Liu(刘方明), Yin-Juan Liu(刘银娟), Lei Qi(戚磊), Wei Ding(丁未), Hong-Xia Gong(龚红霞), Xiao-Lin Ni(倪小林), Duan-Wei He(贺端威)   

  1. 1 Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China;
    2 College of Mechanical and Electrical Engineering, Yangtze Normal University, Chongqing 408100, China
  • 收稿日期:2017-11-27 修回日期:2018-02-10 出版日期:2018-05-05 发布日期:2018-05-05
  • 通讯作者: Zi-Li Kou E-mail:kouzili@scu.edu.cn

Polycrystalline cubic boron nitride prepared with cubic-hexagonal boron nitride under high pressure and high temperature

Ming Yang(杨鸣)1, Zi-Li Kou(寇自力)1, Teng Liu(刘腾)1, Jing-Rui Lu(卢景瑞)1, Fang-Ming Liu(刘方明)2, Yin-Juan Liu(刘银娟)1, Lei Qi(戚磊)1, Wei Ding(丁未)1, Hong-Xia Gong(龚红霞)1, Xiao-Lin Ni(倪小林)1, Duan-Wei He(贺端威)1   

  1. 1 Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China;
    2 College of Mechanical and Electrical Engineering, Yangtze Normal University, Chongqing 408100, China
  • Received:2017-11-27 Revised:2018-02-10 Online:2018-05-05 Published:2018-05-05
  • Contact: Zi-Li Kou E-mail:kouzili@scu.edu.cn

摘要: Polycrystalline cubic boron nitride (PcBN) compacts, using the mixture of submicron cubic boron nitride (cBN) powder and hexagonal BN (hBN) powder as starting materials, were sintered at pressures of 6.5-10.0 GPa and temperature of 1750℃ without additives. In this paper, the sintering behavior and mechanical properties of samples were investigated. The XRD patterns of samples reveal that single cubic phase was observed when the sintering pressure exceeded 7.5 GPa and hBN contents ranged from 20 vol.% to 24 vol.%, which is ascribed to like-internal pressure generated at grain-to-grain contact under high pressure. Transmission electron microscopy (TEM) analysis shows that after high pressure and high temperature (HPHT) treatments, the submicron cBN grains abounded with high-density nanotwins and stacking faults, and this contributed to the outstanding mechanical properties of PcBN. The pure bulk PcBN that was obtained at 7.7 GPa/1750℃ possessed the outstanding properties, including a high Vickers hardness (~61.5 GPa), thermal stability (~1290℃ in air), and high density (~3.46 g/cm3).

关键词: PcBN compact, high temperature and high pressure sintering, PcBN without additive

Abstract: Polycrystalline cubic boron nitride (PcBN) compacts, using the mixture of submicron cubic boron nitride (cBN) powder and hexagonal BN (hBN) powder as starting materials, were sintered at pressures of 6.5-10.0 GPa and temperature of 1750℃ without additives. In this paper, the sintering behavior and mechanical properties of samples were investigated. The XRD patterns of samples reveal that single cubic phase was observed when the sintering pressure exceeded 7.5 GPa and hBN contents ranged from 20 vol.% to 24 vol.%, which is ascribed to like-internal pressure generated at grain-to-grain contact under high pressure. Transmission electron microscopy (TEM) analysis shows that after high pressure and high temperature (HPHT) treatments, the submicron cBN grains abounded with high-density nanotwins and stacking faults, and this contributed to the outstanding mechanical properties of PcBN. The pure bulk PcBN that was obtained at 7.7 GPa/1750℃ possessed the outstanding properties, including a high Vickers hardness (~61.5 GPa), thermal stability (~1290℃ in air), and high density (~3.46 g/cm3).

Key words: PcBN compact, high temperature and high pressure sintering, PcBN without additive

中图分类号:  (Crystallographic aspects of phase transformations; pressure effects)

  • 61.50.Ks
61.72.Ff (Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)) 81.20.Ev (Powder processing: powder metallurgy, compaction, sintering, mechanical alloying, and granulation)