J Mater Sci Technol ›› 2009, Vol. 25 ›› Issue (04): 539-542.

• Articles • Previous Articles     Next Articles

Morphology Change of Metastable Regrown Graphite with Boron Additive under HPHT

Chuanyi Zang1)†, Xiaozhou Chen1), Qiang Hu1), Wei Guo2), Guofeng Huang2), Xiaopeng Jia2)   

  1. 1) Institute of Material Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, China
    2) State Key Laboratory for Superhard Materials, Jilin University, Changchun 130012, China
  • Revised:2008-11-01 Online:2009-07-28 Published:2009-10-10
  • Contact: Chuangyi Zang
  • Supported by:

    the National Natural Science Foundation of China under grant No. 50172018
    the Foundation of He0nan Educational Committee under grant No. 2009A430014
    the Open Research Fund Program of State Key Laboratory of Superhard Materials of Jilin University under grant No. 200801

Abstract:

By temperature gradient method under high pressure and high temperature (HPHT), with NiMnCo alloy as the solvent metal, at diamond-stable region of about 5.4 GPa and 1500 K, metastable regrown graphite crystals of different morphology were synthesized. With B as an additive incorporated into the NiMnCo-C system, metastable regrown graphite crystals of sphere-like shape were firstly obtained under HPHT. If the growth system does not contain B, sheet-like regrown graphite crystals, most with regular hexagonal morphology, are grown upwards and standing vertically in the metal solvent. When B additive of 1.0 wt pct was added into carbon source (graphite powder), all metastable regrown graphite crystals took on the habit of regular sphere-like morphology, and were grown by a spiral layer growth mechanism.

Key words: Graphite, High pressure and high temperature, Temperature gradient method, Morphology