放电等离子体烧结结合高温热处理制备高强高导热氮化硅陶瓷  

High Strength and High Thermal Conductivity Si_(3)N_(4)Ceramics Prepared by Spark Plasma Sintering Combined with High Temperature Heat Treatment

作　　者：李涛 张博 魏智磊 邓康 史忠旗[1] LI Tao;ZHANG Bo;WEI Zhilei;DENG Kang;SHI Zhongqi(State Key Laboratory for Mechanical Behavior of Materials,School of Materials Science and Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学材料科学与工程学院,金属材料强度国家重点实验室,西安710049

出　　处：《硅酸盐学报》2024年第9期2934-2941,共8页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金青年科学基金项目(52302069)。

摘　　要：采用放电等离子体烧结(SPS)结合高温热处理工艺,以α-Si_(3)N_(4)为主要原料、MgSiN_(2)和Y_(2)O_(3)为复合烧结助剂制备出兼具高强度和高导热性能的Si_(3)N_(4)陶瓷,研究了SPS温度对Si_(3)N_(4)陶瓷致密化过程和热导率的影响,并分析了高温热处理温度对Si_(3)N_(4)陶瓷微观结构和性能的影响。结果表明,Si_(3)N_(4)陶瓷的致密度和热导率随着SPS温度的升高而提高,在1600℃保温5 min即可制备出致密度约为99%的Si_(3)N_(4)陶瓷样品。对其进行高温热处理发现,样品的热导率随着热处理温度的升高而提高,抗弯强度则与之相反。经1800℃热处理的样品,热导率为57.36 W·m^(-1)·K^(-1),相较未经热处理的样品提升了13.27%,同时抗弯强度仍保持在743 MPa的较高水平。Introduction Silicon nitride(Si_(3)N_(4))ceramics are considered to be one of the most promising ceramic substrate materials due to their good insulation,low coefficient of thermal expansion and high mechanical properties.However,the thermal conductivity of Si_(3)N_(4)ceramics prepared by conventional methods is low(<50 W·m^(-1)·K^(-1)),which greatly affects the reliability of chips and even causes the failure of electronic devices.New methods such as gas pressure sintering(GPS),and sintered reaction-bonded silicon nitride(SRBSN)have been employed to fabricate Si_(3)N_(4)ceramics with high thermal conductivity and high bending strength.Nevertheless,the sintering temperature of both GPS and SRBSN is high and the holding time is too long,which lead to the high cost and limit its applications.Spark plasma sintering(SPS)can produce ceramics with high density in a relatively short time,while the short soaking time is not suitable to improve the thermal conductivity.High-temperature heat treatment can promote the growth of Si_(3)N_(4)grains,and thus improves the thermal conductivity of Si_(3)N_(4)ceramics.Therefore,it is expected that Si_(3)N_(4)ceramics with high bending strength and high thermal conductivity can be prepared at a lower temperature and a shorter time by the combination of SPS and high-temperature heat treatment processes.Methods Si_(3)N_(4)ceramics were prepared by SPS at 1400,1500,1600℃and 1700℃for 5 min usingα-Si_(3)N_(4),Y_(2)O_(3)and MgSiN_(2)as raw materials.The obtained samples with the best overall properties were then selected and put into a gas pressure furnace to be heated at different temperatures(1600,1700℃,and 1800℃)for 3 h.Density and open porosity of the sintered samples were tested by Archimedes method.The phase composition of samples was analyzed by X-ray diffractometer(XRD).Samples were polished and then etched in molten NaOH at 500℃for 20 s to observe the microstructures using a field emission Scanning electron microScope(FESEM).The diameters of at least 200 grains in th

关 键 词：氮化硅 放电等离子体烧结 高温热处理 热导率 抗弯强度 

分 类 号：TB321[一般工业技术—材料科学与工程]