Articles
  • Microstructural evolution of chemically vapor-deposited tantalum carbide at elevated temperature

  • Jangwon Hana,b, SangMin Jeongc, Ji Yeon Parkb, Hyun-Geun Leeb, Weon-Ju Kimb, Chan Parka and Daejong Kimb,*

  • aSchool of Materials Science & Engineering, Seoul National University, Seoul 08826, Republic of Korea
    bNuclear Materials Development Division, Korea Atomic Energy Research Institute, Daejeon 34057, Republic of Korea
    cSiC Division, HANA Materials, Asan 31413, Republic of Korea

  • This article is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Tantalum carbide (TaC), one of the ultra-high temperature ceramics, was chemically vapor-deposited at 1100 - 1300 oC in a TaCl5-C3H6-H2 system. Microstructural evolution of TaC was evaluated after heat treatment at 1850 oC for 4 hours. Various tantalum carbides with different orientation and microstructure were obtained depending on the deposition temperature and the position. Crystallophic preferred orientation of the TaC changed from highly oriented (111) and (200), to random texture, as deposition temperatures increase. The continuous feed of TaCl4 powders using screw-driven feeder led to the fluctuation of TaCl4 partial pressure during the deposition process, resulted in a low crystallinity and formation of micropores. A dense TaC was only obtained at the high partial pressure of TaCl5. Heat treatment dramatically enhanced crystallinity but micropores were coalesced into large pores along grain boundaries. The influence of crystallophic orientation and microstructure on microstructural evolution and hardness during heat treatment were investigated


Keywords: Tantalum Carbide, Chemical Vapor Deposition, Heat treatment, Orientation

This Article

  • 2022; 23(6): 751-757

    Published on Dec 31, 2022

  • 10.36410/jcpr.2022.23.6.751
  • Received on Dec 4, 2019
  • Revised on Mar 23, 2020
  • Accepted on Mar 24, 2020

Correspondence to

  • Daejong Kim

  • Nuclear Materials Development Division, Korea Atomic Energy Research Institute, Daejeon 34057, Republic of Korea
    Tel : +82-42-868-4559 Fax: +82-42-868-8549

  • E-mail: dkim@kaeri.re.kr