点击次数：

论文类型：期刊论文

发表时间：2012-12-01

发表刊物：JOURNAL OF THE EUROPEAN CERAMIC SOCIETY

收录刊物：Scopus、SCIE

卷号：32

期号：16

页面范围：4195-4204

ISSN号：0955-2219

关键字：Cooling rate; Eutectic ceramic; Undercooling; Mechanical properties; Microstructure

摘要：Melt-grown Al2O3/YAG/ZrO2 ternary eutectic samples were solidified by quenching and with controlled cooling rates of 10, 50, and 250 degrees C/min, respectively. Effect of cooling rate on microstructure and mechanical properties were examined. With the increase of cooling rate, three classical characteristic microstructures are obtained and developed from colony structure to dendrite structure and to cell structure. In the quenching process, the sample consists of lamellar eutectic cells and its fracture toughness increases to 4.13 +/- 0.8 MPa m(1/2). The microstructure transitions with the cooling rate are attributed to instability of the solid liquid interface. In this work, the interface instability is analyzed to explain the microstructure evolutions in terms of undercooling and characteristic lengths of solute diffusion and capillarity effect. (C) 2012 Elsevier Ltd. All rights reserved.