• Title/Summary/Keyword: Additive im-purity

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Effect of Impurities in Grain Boundary Phases on Wear Behavior of $Si_3N_4$ (질화규소의 입계상에 존재하는 불순물이 마모에 미치는 영향)

  • 오윤석;임대순;이경호
    • Journal of the Korean Ceramic Society
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    • v.33 no.3
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    • pp.277-284
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    • 1996
  • The water test results indicated that the impurities had detrimetal effect on the wear resistance of silicon nitride and the effects were getting severe as the temperature increased. Especially when Ca existed as an impurity the detrimental effects was the most severe. These results were resulted from the fact that impurities lowered the mechanical properties of the grain boundary phase of silicon nitride. The wear test results of glass/glass-ceramic specimens having a similar composition to the grain boundary phase of silicon nitride revea-led that the specimen containing CaO showed the lowest wear resistance. The existence of Fe and Ca at the grain boundary phase assisted forming a grain boundary phase with relatively low refractoriness. Therefore at a given wear condition the removal of deformed layer would be easier. The results showed that the glass phases could be modified by heat-treatment and this modification improved tribological characteristics of the silicon nitride.

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