(1. 蘭州理工大學(xué) 甘肅省有色金屬新材料省部共建國家重點(diǎn)實(shí)驗(yàn)室，蘭州 730050；
2. 蘭州理工大學(xué) 有色金屬合金省部共建教育部重點(diǎn)實(shí)驗(yàn)室，蘭州 730050)
摘 要: 采用XRD、SEM和EPMA技術(shù)研究MoSi2棒材的高溫碳化行為。結(jié)果顯示：試樣心部仍為MoSi2相，碳化產(chǎn)物為Mo5Si3C和Mo2C；碳化層組織疏松，有大量圓形孔洞存在，厚度約為500~800 μm，心部組織表現(xiàn)為MoSi2沿晶和穿晶脆性斷裂特征；碳化產(chǎn)物位于三元Mo-Si-C平衡相圖中Mo5Si3、Mo5Si3C和Mo2C三相區(qū)內(nèi)，試樣由內(nèi)到外，Mo2C含量逐漸升高；碳化產(chǎn)物主要由Mo5Si3碳化形成，而并非MoSi2的直接碳化產(chǎn)物。
關(guān)鍵字: MoSi2；碳化行為；Mo5Si3C；加熱元件
（1. State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials,
Lanzhou University of Technology, Lanzhou 730050, China;
2. Key Laboratory of Non-ferrous Metal Alloys, Ministry of Education,
Lanzhou University of Technology, Lanzhou 730050, China）
Abstract:The carbonation behavior of MoSi2 at high temperature was investigated by XRD，SEM and EPMA. The results show that the internal part of the sample consists of MoSi2. The major carbonization productions are Mo5Si3C and Mo2C. The structure of carbonized layer is loose and there is a large number of circular holes with thickness of about 500−800 μm. The internal microstructure of the specimen shows brittle fracture characteristics of MoSi2. The carbonized products locate at the Mo5Si3, Mo5Si3C and Mo2C three-phase region of the ternary Mo-Si-C equilibrium phase diagram. The content of Mo2C gradually increases from inner to extra of the sample. The carbonized products form from carbonizing Mo5Si3, rather than a direct carbonization product of MoSi2.
Key words: MoSi2; carbonation behavior; Mo5Si3C; heating element
