A Study on the Manufacture of WC MMCs by In-situ Reaction Process(1);The Formation Mechanism of Interfacial Reaction Layer in Cast-bonded Cast iron/W wire and Its Structure

기지내 반응법에 의한 WC 복합재료의 제조에 관한 연구(1);주조접합된 주철/텅스텐 와이어의 계면반응층 생성기구와 조직특성

  • Park, Heung-Il (Pusan National Univ. of Technology, Dept. of Production and Welding Eng.) ;
  • Kim, Chang-Up (Taegue Master's Collage, Dept. of Metallurgical Eng.) ;
  • Huh, Bo-Young (Kyungsang Univ., Dept. of Metallurgical Eng.) ;
  • Lee, Sung-Youl (Korea Marine Univ., Dept. of Materials Eng.) ;
  • Kim, Chang-Gyu (Pusan National Univ. of Technology, Dept. of Metallurgical Eng.)
  • 박흥일 (부산공업대학교 생산가공공학과) ;
  • 김창업 (대구기능대학 금속공학과) ;
  • 허보영 (경상대학교 금속공학과) ;
  • 이성렬 (한국해양대학교 재료공학과) ;
  • 김창규 (부산공업대학교 금속공학과)
  • Published : 1995.06.20

Abstract

Iron-based metal matrix composites have been recently investigated for the use of inexpensive abrasion resistance material. This paper carried out to investigate the in-situ reaction effects on the microstructural characteristics and the formation mechanism of tungsten carbides in a white cast iron matrix. The specimens of Fe-3.2%C-2.8%Si alloy cast-bonded with tungsten wire were cast in the metal mold and isothermally heat treated at $950^{\circ}C$ up to 48 hours. The typical microstructure of heat treated specimens showed the reaction layer of WC at the interface of tungsten wire and the carbon depletion zone between the WC layer and the matrix. During the formation of WC layer, if the carbon supply is insufficient due to the decarburization of matrix or the isolation of matrix by cast-bonded W wires, the reaction layer develops coarse hexagonal crystalline WC. From the microstructural investigation, it was found that the volume of WC layer and the carbon depletion zone increased linearly with the isothermal heat treating time. This results supported that the formation rate of WC in the white cast iron matrix is controlled by the interfacial reaction with a constant reaction rate.

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