Effect of Glass Frit on the Sintering Behavior and Mechanical Properties of 3Y-ZrO2

3Y-지르코니아 조성에서 Glass Frit의 첨가량에 따른 소결 거동 및 기계적 특성의 변화

  • Lee, Gyu-Sun (Dept. of Dental Technology, Dongnam Health College) ;
  • Kwon, Eun-Ja (Dept. of Dental Technology, Hyejeon College) ;
  • Lee, Chae Hyun (Dept. Materials Engineering, Paichai University)
  • Received : 2008.10.10
  • Accepted : 2009.03.09
  • Published : 2009.03.30

Abstract

The effect of glass frit on the sintering behavior and mechanical properties of 3 mol% $Y_2O_3$-doped zirconia($3Y-ZrO_2$) have been studied. Up to 30 wt% of glass frit was added to $3Y-ZrO_2$. Sintering was performed in a box furnace up to $1300^{\circ}C$ for specimens with glass frit and $1600^{\circ}C$ for specimens without glass frit in air for 1h. Relative density and mechanical properties were measured to investigate the effect of glass frit. The addition of glass frit enhanced both sintered density and mechanical properties of $3Y-ZrO_2$ which is suitable for dental applications. Maximum sintered density 93.3% of theoretical density was obtained with the specimens containing 30 wt% frit sintered at $1300^{\circ}C$, whereas the optimum amount of frit addition for mechanical properties was determined as 10 wt%. Maximum value of strength, fracture toughness, and Vickers microhardness for specimens with glass frit were 206 MPa, $3.4\;MPa\;m^{1/2}$, and 5.3 GPa, respectively.

본 연구에서는 치과재료로 유망한 지르코니아에 frit을 첨가하고 frit의 첨가량과 소결 온도에 따른 소결밀도의 변화와 기계적 특성의 변화를 고찰하고자 하였다. 지르코니아에 frit을 첨가함으로써 소결밀도의 향상 효과를 얻을 수 있었다. 그러나 소결온도가 $1400^{\circ}C$에 이르면 유리질에 의해 시편이 형체를 유지할 수 없는 상태가 되기 때문에 소결온도는 $1300^{\circ}C$로 제한되었다. 일반적으로 frit의 첨가량이 많아지고 소결온도가 높아짐에 따라 소결밀도가 증가하는 경향을 나타내었다. 소결체에서 얻은 최대 소결밀도는 frit을 20 wt% 첨가하고 $1300^{\circ}C$에서 소결한 경우에서 93.3 %를 나타내었다. 이들 시편에 대해 기계적인 물성을 측정한 결과 곡강도, 파괴인성, Vickers 미세경도 등의 물성이 소결온도에 따라 향상되는 것을 알 수 있었으며, frit의 첨가량에 따라서는 10 wt% 첨가된 경우에서 최대값을 나타내는 것을 알 수 있었다. 3점 곡강도, 파괴인성, Vickers 미세경도의 최대값은 각각 206 MPa, $3.4\;MPa\;m^{1/2}$, 그리고 5.3 GPa로 나타났다. 이상의 결과 지르코니아에 frit을 첨가하면 소결온도를 낮추고 소결밀도를 향상시키는 한편 우수한 기계적 특성을 가진 지르코니아에 비하여 낮은 물성을 가진 frit의 첨가로 인하여 밀도향상 효과와 기계적 특성 저하 효과가 서로 작용하여 10 wt%의 frit이 첨가된 경우에 기계적 특성이 최대값을 나타내는 것으로 판단된다.

Keywords

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