Ageing of zirconia-toughened alumina ceramics under different hydrothermal conditions
Abstract Changes in the crystalline phases of ZrO 2 in different zirconia-toughened alumina (ZTA) compositions were studied at lower temperature (150–250 °C) by exposing them in a stream of humid air for a period of 24 h. Fresh samples of these compositions were also aged in an autoclave with superheated water for 2.5 h in the same temperature range, and the degree of phase transformation was compared with data from the previous samples to establish the effect of pressure on this phenomenon. It was observed for all the ZTA compositions that phase transformation increased monotonically with ageing time, temperature and pressure, although for the compositions with a lower percentage (15 vol%) of zirconia (3 mol% Y 2 O 3 ), ageing in an autoclave was more detrimental particularly at lower temperature. As the ageing temperature increased in the composition with 15 vol% ZrO 2 (3 mol% Y 2 O 3 ), the influence of ageing duration on phase transformation of ZrO 2 increased and the effect for 24 h of exposure time was found to be even more catastrophic than that of autoclave pressure at 250 °C. On the other hand, for the ZTA compositions containing more than 15 vol% zirconia (3 mol% Y 2 O 3 ), the damaging effect of ageing in the autoclave was greater and this difference increased with increase in temperature.
유료 다운로드의 경우 해당 사이트의 정책에 따라 신규 회원가입, 로그인, 유료 구매 등이 필요할 수 있습니다. 해당 사이트에서 발생하는 귀하의 모든 정보활동은 NDSL의 서비스 정책과 무관합니다.
NDSL에서는 해당 원문을 복사서비스하고 있습니다. 위의 원문복사신청 또는 장바구니 담기를 통하여 원문복사서비스 이용이 가능합니다.
- 이 논문과 함께 출판된 논문 + 더보기