Journal of the Korean Ceramic Society (한국세라믹학회지)

The Korean Ceramic Society (한국세라믹학회)
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Effect of Co additive on the Abnormal Grain Growth of WC

Co첨가에 의한 WC의 비정상입성장

  • Published : 2004.01.01
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Abstract

The effect of Co additive on the microstructural evolusion of WC was investigated. A small amount of Co powder was placed on the top-center of the pure WC powder compact and then sintered at 1950$^{\circ}C$. During sintering some abnormally large WC grains of different size and shape observed depending on the distance from the liquid source. However, in the region far away from Co liquid source, it showed low densification and the grains of WC were very small and uniform in size. A small amount of Co liquid phase has a remarkable influence on the AGG of WC and it has been explained in terms of 2-D nucleation and growth mechanism.

WC에 소량의 Co를 첨가하여 그에 따른 미세조직의 변화를 관찰하였다. 순수한 WC를 성형하여 그 윗부분에 Co를 올려놓고 195$0^{\circ}C$에서 소결을 행한 결과, WC시편에서는 Co상이 놓여 액상을 형성한 영역으로부터 거리에 따라 입자의 크기와 모양이 다른 활발한 비정상입성장이 관찰되었다. 그러나, Co상이 놓인 영역으로부터 떨어진 시편 아래 영역에서는 낮은 치밀화와 함께 비정상입성장은 일어나지 않았다. 즉, Co 액상량은 WC의 비정상입성장 현상에 지대한 영향을 주었으며, 이러한 비정장입정장 현상은 2차원 핵생성 기구와 그에 따른 입성장기구로 설명이 가능하였다.

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