PDF《硅酸盐学报》

第44 卷第

3 期201

6 年3月硅酸盐学报Vol.

44,No.

3 March,2016 JOURNAL OF THE CHINESE CERAMIC SOCIETY http://www.gxyb.cbpt.cnki.net DOI:10.14062/j.issn.0454-5648.2016.03.09 烧结温度对放电等离子烧结氮化硅陶瓷显微结构和力学性能的影响 刘剑1 ,谢志鹏2 ,李志坚1 (1. 辽宁科技大学,辽宁 鞍山 114051;

2. 新型陶瓷与精细工艺国家重点实验室,北京 100084) 摘要:以亚微米级氮化硅为原料、Al2O3CY2O3 为烧结助剂,利用放电等离子烧结(spark plasma sintering,SPS)烧结技术制 备氮化硅陶瓷.用X射线衍射和扫描电子显微镜对试样的物相组成和显微结构进行分析,研究了烧结温度对氮化硅陶瓷力学 性能和显微结构的影响.结果表明,采用 SPS 烧结技术可在较低温度下获得致密度较高、综合力学性能较好的β相氮化硅陶 瓷.随着烧结温度的提高,样品致密度、抗弯强度、断裂韧性均不断增大,在1550 ℃时,其抗弯强度和断裂韧性分别达 到973.74 MPa 和8.23 MPa?m1/2 .在1550 ℃以下,陶瓷样品中β相氮化硅含量可达到 98%,显微结构均匀,晶粒发育良好、 呈长柱状,晶间紧密连接,晶间气孔较少.继续升高温度,部分晶粒发生异常长大,产生了更多的显微孔洞,抗弯强度急 剧下降. 关键词:氮化硅;

放电等离子烧结;

烧结温度;

力学性能;

显微结构 中图分类号:TQ174.75 文献标志码:A 文章编号:0454C5648(2016)03C0403C05 网络出版时间: 网络出版地址: Effect of Sintering Temperature on Microstructure and Properties of Silicon Nitride Ceramics by Spark Plasma Sintering LIU Jian1 , XIE Zhipeng2 , LI Zhijian1 (1. University of Science and Technology, Anshan 114051, Liaoning, China;

2. State Key Laboratory of New Ceramics and Fine Processing, Beijing 100084, China) Abstract: The high-performance silicon nitride ceramics were prepared via spark plasma sintering (SPS) with submicron-sized powder of silicon nitride as a raw material and Al2O3CY2O3 as a sintering aid. The phase constitution and microstructure of specimens were analyzed by X-ray diffraction and scanning electronic microscopy. The effect of sintering temperature on the microstructure and mechanical properties of silicon nitride ceramics were investigated. The results show that β-phase silicon nitride ceramic with a high density and good mechanical properties can be obtained at a lower sintering temperature by SPS. The density, flexural strength and fracture toughness of the samples improve with the increase of the sintering temperature. The flexural strength and fracture toughness of the samples sintered at

1 500 ℃ are 973.74 MPa and 8.23 MPa?m1/2 , respectively. According to the phase composition and microstructure analysis, the β-phase content of silicon nitride ceramics is 98%. The elongated columnar silicon nitride grains are uniform and well-developed. The compact connection between the grains results in the less pores of grain boundaries. The abnormal growth of some grains produces the more microscopic pores, leading to that the flexural strength decreases as sintering temperature further incerases. Keywords: silicon nitride;

spark plasma sintering;

sintering temperature;

mechanical properties;

microstructure 随着现代科学的不断发展,人们对材料的要求 越来越严格, 对高强度材料提出了更为苛刻的要求. 氮化硅陶瓷作为高温结构陶瓷,具有强度高、硬度 大、密度低、导热系数低、化学性能稳定、耐磨损、 耐腐蚀等优异性能,目前已广泛应用于航空航天、 机械工业、电子电力、装甲、化工等领域.收稿日期:2015C12C18. 修订日期:2015C01C04. 基金项目:国家自然科学基金重点项目(51232004)资助. 第一作者:刘剑(1990―),男,硕士研究生. 通信作者:李志坚(1958―),男,教授. Received date: 2015C12C18. Revised date: 2015C01C04. First author: LIU Jian (1990C), male, Master candidate. E-mail: [email protected] Correspondent author: LI Zhijian (1958C), male, Professor. E-mail: [email protected] ・