工程科学学报，第41卷，第9期：1168-1175,2019年9月 Chinese Journal of Engineering,Vol.41,No.9:1168-1175,September 2019 DOI:10.13374/j.issn2095-9389.2019.09.008;http://journals.ustb.edu.cn 原位合成SiC颗粒增强MoSi,基复合材料的900℃长 期氧化行为 王 超)，段立辉2)，张来启2)四 1)内蒙古科技大学材料与冶金学院，包头0140102)北京科技大学新金属材料国家重点实验室，北京100083 ☒通信作者，E-mail:zhanglq(@usth.cdu.cm 摘要研究了不同体积分数原位合成SiC颗粒增强MSi2基复合材料在900℃空气中1000h的长期氧化行为.复合材料氧 化1000h后，均未发生pst现象.6种材料都表现出优异的氧化抗力，原位合成的复合材料的氧化抗力好于传统的通过热压 商用MoSi2粉末和SiC粉末混合物制备的复合材料（外加复合材料）.复合材料氧化膜表层为连续致密的a-SiO2(α-石英).下 层为Mo,Si,复合材料的氧化过程不仅是0，与MoSi,的作用，SC也同时发生了氧化.材料900℃下发生硅的选择性氧化，正 是这种硅的选择性氧化在MSi,的表面自发形成一层致密的SiO,保护膜，使材料表现出优异的长期氧化抗力. 关键词复合材料；MoSi2;SiC颗粒增强体；原位合成；低温氧化行为；pet现象 分类号TB333 Long-term oxidation behavior of in situ synthesized SiC particulate-reinforced MoSi, matrix composites at 900 C WANG Chao,DUAN Li-hui),ZHANG Lai-gi) 1)School of Materials and Metallurgy,Inner Mongolia University of Science and Technology,Baotou 014010,China 2)State Key Laboratory for Advanced Metals and Materials,University of Seience and Technology Beijing,Beijing 100083.China Corresponding author,E-mail:zhanglg@ustb.edu.cn ABSTRACT MoSi,intermetallic is well known as one of the most promising compounds used as structural components due to its high melting point,relatively low density,excellent oxidation resistance,and good strength at high temperatures.Unfortunately,MoSi has poor toughness at low temperatures and low creep strength at elevated temperatures.Especially,MoSi alloy usually exhibits severe "pest oxidation"at low temperatures of between 400 and 900 C.These problems limit the applications of MoSi,alloys.The main methods to solve these problems are alloying and compounding.Unfortunately,so far,the problem of low-temperature oxidation resist- ance of MoSi has not been completely solved,and its composite materials are reinforced using external means.In a previous work,SiC particle-reinforced MoSi matrix composites were prepared by an in situ synthesis technique,and the microstructures and the mechanical behaviors at room temperature and high temperature were systematically studied.In this work,the long-term oxidation behavior of in si- tu synthesized SiC particulate-reinforced MoSi,matrix composites with different volume fractions and occurring at 900C for 1000 h was investigated.The composites are not observed to disintegrate (pest)after oxidation for 1000h.The oxidation resistances of six kinds of materials appear excellent.The composite synthesized by in situ possesses higher oxidation resistance than the traditional composite, which is fabricated by hot-pressing the mixture of commercial powders of MoSi and SiC.The surface of scales consists of a-SiO(a- quartz),and the subsurface is composed of MoSi.The oxidation of the composites is conducted not only between MoSi,and O,,but 收稿日期：2019-06-20 基金项目：国家自然科学基金资助项目(51871012)：金属材料磨损控制与成型技术国家地方联合工程研究中心开放课题资助项目 (HKDNM201805)工程科学学报,第 41 卷,第 9 期:1168鄄鄄1175,2019 年 9 月 Chinese Journal of Engineering, Vol. 41, No. 9: 1168鄄鄄1175, September 2019 DOI: 10. 13374 / j. issn2095鄄鄄9389. 2019. 09. 008; http: / / journals. ustb. edu. cn 原位合成 SiC 颗粒增强 MoSi 2 基复合材料的 900 益 长 期氧化行为 王 超1) , 段立辉2) , 张来启2) 苣 1)内蒙古科技大学材料与冶金学院, 包头 014010 2) 北京科技大学新金属材料国家重点实验室, 北京 100083 苣通信作者,E鄄mail: zhanglq@ ustb. edu. cn 摘 要 研究了不同体积分数原位合成 SiC 颗粒增强 MoSi 2 基复合材料在 900 益空气中 1000 h 的长期氧化行为. 复合材料氧 化 1000 h 后,均未发生 pest 现象. 6 种材料都表现出优异的氧化抗力,原位合成的复合材料的氧化抗力好于传统的通过热压 商用 MoSi 2 粉末和 SiC 粉末混合物制备的复合材料(外加复合材料). 复合材料氧化膜表层为连续致密的 琢鄄SiO2 (琢鄄石英),下 层为 Mo5 Si 3 ,复合材料的氧化过程不仅是 O2 与 MoSi 2 的作用,SiC 也同时发生了氧化. 材料 900 益下发生硅的选择性氧化,正 是这种硅的选择性氧化在 MoSi 2 的表面自发形成一层致密的 SiO2 保护膜,使材料表现出优异的长期氧化抗力. 关键词 复合材料; MoSi 2 ; SiC 颗粒增强体; 原位合成; 低温氧化行为; pest 现象 分类号 TB333 收稿日期: 2019鄄鄄06鄄鄄20 基金项目: 国家自然科学基金资助项目( 51871012 );金属材料磨损控制与成型技术国家地方联合工程研究中心开放课题资助项目 (HKDNM201805) Long鄄term oxidation behavior of in situ synthesized SiC particulate鄄reinforced MoSi 2 matrix composites at 900 益 WANG Chao 1) , DUAN Li鄄hui 2) , ZHANG Lai鄄qi 2) 苣 1)School of Materials and Metallurgy, Inner Mongolia University of Science and Technology, Baotou 014010, China 2)State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China 苣Corresponding author, E鄄mail: zhanglq@ ustb. edu. cn ABSTRACT MoSi 2 intermetallic is well known as one of the most promising compounds used as structural components due to its high melting point, relatively low density, excellent oxidation resistance, and good strength at high temperatures. Unfortunately, MoSi 2 has poor toughness at low temperatures and low creep strength at elevated temperatures. Especially, MoSi 2 alloy usually exhibits severe “pest oxidation冶 at low temperatures of between 400 and 900 益 . These problems limit the applications of MoSi 2 alloys. The main methods to solve these problems are alloying and compounding. Unfortunately, so far, the problem of low鄄temperature oxidation resist鄄 ance of MoSi 2 has not been completely solved, and its composite materials are reinforced using external means. In a previous work, SiC particle鄄reinforced MoSi 2 matrix composites were prepared by an in situ synthesis technique, and the microstructures and the mechanical behaviors at room temperature and high temperature were systematically studied. In this work, the long鄄term oxidation behavior of in si鄄 tu synthesized SiC particulate鄄reinforced MoSi 2 matrix composites with different volume fractions and occurring at 900 益 for 1000 h was investigated. The composites are not observed to disintegrate (pest) after oxidation for 1000 h. The oxidation resistances of six kinds of materials appear excellent. The composite synthesized by in situ possesses higher oxidation resistance than the traditional composite, which is fabricated by hot鄄pressing the mixture of commercial powders of MoSi 2 and SiC. The surface of scales consists of 琢鄄SiO2 (琢鄄 quartz), and the subsurface is composed of Mo5 Si 3 . The oxidation of the composites is conducted not only between MoSi 2 and O2 , but