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无机材料学报

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Sialon基陶瓷材料制备工艺及显微结构变化对力学性能的影响

刘茜1; 许钫钫1; 阮美玲1; 高濂1; THOMPSOND．P．2; 温树林1   

  1. 1. 中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室; 上海 200050; 2. 英国纽卡斯尔大学材料系, NE1 7RU, 英国
  • 收稿日期:1999-04-29 修回日期:1999-06-01 出版日期:1999-12-20 网络出版日期:1999-12-20

Influence of Processing and Microstructure on Mechanical Properties in Sialon-based Ceramics

LIU Qian1; XU Fang-Fang1; RUAN Mei-Ling2; GAO Lian1; WEN Shu-Lin 1   

  1. 1.State Key Lab of High Performance Ceramics and Superfine Microstructure; Shanghai Institute of Ceramics; Chinese Academy of Sciences; Shanghai 200050; China; 2. Materials Division, Dept. of Mechanical, Materials and Manufacturing, University of Newcastle upon Tyne, NE1 7RU, United Kingdom
  • Received:1999-04-29 Revised:1999-06-01 Published:1999-12-20 Online:1999-12-20

PDF (PC)

917

被引次数

13

摘要： 系统研究了通过外部添加增韧相和热处理诱发原位自增韧机制等工艺因素控制所引起的三种Sialon基陶瓷材料的显微结构变化及其对力学性能的影响．研究内容包括：1．TiN（p）、MoSi2（p）、SiC（p）和SiC（w）第二相物质复合Sialon陶瓷的界面结合状态及其增韧效果；2．利用Nd2O3、Dy2O3和Yb2O3典型稀土氧化物作为烧结添加剂，制备α／β两相复合Sialon材料，诱发β相长颗粒生长，导致类晶须长颗粒原位自增韧机制发生作用；3．α－Sialon长颗粒的成核及生长机制．研究结果表明：对于TiN（p）、MoSi2（p）、SiC（p）和SiC（w）第二相复合Sialon陶瓷，基质相与第二相的界面结合状态及第二相颗粒临界粒径是制约复相材料韧性的主要因素．对于Nd2O3、Dy2O3和Yb2O3典型稀土氧化物Sialon材料，轻稀土Nd2O3是良好的烧结助剂，且Nd－Sialon相变程度极高，热处理诱发大量长颗粒β－Sialon相生成是其具有高韧性的主要原因（最高断裂韧性值达7．0MPa·m1／2）．重稀土Yb2O3不仅是良好的烧结助剂，同时也是有效的α－Sialon稳定剂，体系内存在大量等轴状α－Sialon颗粒, 使此种材料三星度高达18.00GPa. 中稀土Dy2O3的作用介于轻稀土Nd2O3重稀土Yb2O3之间. α－Sialon长颗粒的特殊生长机理源于异相成核和各向异性外延生长二个过程.

关键词: Sialon基陶瓷, 第二相增韧, 原位增韧, 显微结构, 力学性能

Abstract: The influence of processing and microstructure on the mechanical properties of Sialon-based ceramics,
in-situ self-toughening induced by heat treatment and second-phase toughened, was investigated. Three kinds of Sialon-based ceramic materials were covered
in the research: 1. TiB( p), MoSi2( p), SiC(p), and SiC(w) second-phase reinforced Sialon materials; 2. α/β-double-phase-Sialon ceramics, using rare earth oxides Nd2O3,
Dy2O3, and Yb2O3 as sintering additives, 3. Sialon ceramics with elongated α-sialon grains. The experimental resules showed that
as to TiB(p), MoSi2(p), SiC(p), and SiC(w) second-phase reinforced Sialon materials, the toughening effect is mainly controlled by the bonding
between matrix and second-phase and the critical size of second-phase particles. In Nd2O3-, Dy2O3-, and Yb2O3-added Sialon
ceramics, Nd2O3 is a kind of effective sintering additive and Nd-Sialon possesses the highest K1c value (7.0 MPa·m1/2 due to the
elongated β-Sialon grains developed by heat treatment in order to induce in-situ self-toughening mechanism. Yb2O3 is not only an effective sintering additive, but also a useful
α-Sialon stabilizer, so Yb-Sialon is hard, with a highest Vickers hardness Hv10 of 18.0 GPa, because of the existing of
equiaxed α-Sialon grains in the samples. The action of Dy2O3 is between Nd2O3 and Yb2O3. The growth mechanism of elongated
α-sialon grains is declared to be the heterogeneous nucleation and anisotropic growth.

Key words: Sialon-based ceramics, second-phase toughening, in-situ toughening, microstructure, mechanical property

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