B4C颗粒对C/C-SiC复合材料微观结构与力学性能的影响  

Effect of B4C particles on microstructure and mechanical properties of C/C-SiC composites

作　　者：汤振霄 彭可[1] 向秋玲 易君 易茂中[1] TANG Zhenxiao;PENG Ke;XIANG Qiuling;YI Jun;YI Maozhong(State Key Laboratory for Powder Metallurgy,Central South University,Changsha 410083)

机构地区：[1]中南大学粉末冶金国家重点实验室

出　　处：《粉末冶金材料科学与工程》2019年第6期542-548,共7页Materials Science and Engineering of Powder Metallurgy

基　　金：装备预研相关基础研究(4142202XXXX);湖南省自然科学基金资助项目(2017JJ2320)

摘　　要：采用浆料浸渗结合先驱体浸渍−裂解法制备B4C颗粒改性C/C-SiC复合材料,研究B4C颗粒对C/C-SiC复合材料力学行为的影响。结果表明,B4C颗粒改性的C/C-SiC复合材料的抗弯强度和断裂韧性分别为250.41 MPa和13.56 MPa·m^1/2,与C/C-SiC复合材料相比,其抗弯强度下降45.5%,而断裂韧性提高46.0%。B4C颗粒可促进SiC基体的烧结,但由于大量闭孔和基体弱界面的形成,导致材料抗弯强度降低。B4C颗粒改性的C/C-SiC复合材料断裂韧性提高的主要原因在于,B4C颗粒与SiC基体中的弱界面使裂纹在SiC基体中得到有效偏转,增加了裂纹在基体中的扩展路径,使得材料的断裂韧性提高。B4C particles modified C/C-SiC composites were prepared by slurry infiltration combined with precursor infiltration and pyrolysis.The effect of the addition of B4C particles on the mechanical properties of C/C-SiC composites was investigated.The results show that,the flexural strength and fracture toughness of B4C particles modified C/C-SiC composites are 250.41 MPa and 13.56 MPa·m^1/2,respectively.Compared with C/C-SiC composites,the flexural strength decreases by 45.5%,the toughness increases by 46.0%.The B4C particles can promote the sintering of SiC matrix.However,the bending strength of the composites decrease due to the formation of a large number of closed pores and weak interfaces of the matrix.The main reason for the improvement of the fracture toughness of the C/C-SiC composites modified by B4C particles is that the weak interface between B4C particles and SiC matrix make the cracks deflect effectively in the SiC matrix,increase the propagation path of the cracks in the matrix,and improve the fracture toughness of the composites.

关 键 词：C/C-SIC复合材料 B4C改性 浆料浸渍 先驱体浸渍裂解 力学性能 

分 类 号：TB332[一般工业技术—材料科学与工程]