摘要
以Mo-Si-B4C混合粉末为涂层原料,采用放电等离子烧结在铌合金表面原位反应烧结制备MoSi2-B4C复合涂层,研究涂层组织形成过程及界面反应特征,考察涂层在1450℃下的抗氧化性能。结果表明,在烧结的升温阶段,MoSi2相就已完全形成,而在保温的初期阶段,部分B4C颗粒又与邻近的MoSi2反应生成了SiC和Mo2B5。烧结过程中,涂层中的Si和B向基体合金扩散,形成了由NbSi2+NbB外层和Nb5Si3内层组成的互扩散区。涂层在1450℃至少100 h内可有效保护基体,表面生成了致密的SiO_(2)-B2O_(3)氧化膜,而互扩散区内NbB的存在有效阻碍了氧化过程涂层中Si的内扩散。
MoSi2-B4C composite coatings were prepared on Nb alloy by spark plasma sintering process using pure Mo,Si and B4C powders as the coating starting materials.The microstructure formation process and interface reaction characteristics of the coatings during SPS were studied.The oxidation resistance of the coatings at 1450℃ was investigated.The results show that the MoSi2 phase forms completely in the coatings during the heating stage of sintering,and the B4C particles react with the neighboring MoSi2 to form SiC and Mo2B5 at the initial stage of holding time.During the sintering process,elements Si and B diffuse inwardly from the coatings to the Nb substrate,forming an interdiffusion zone composed of NbSi2+NbB outer layer and Nb5Si3 inner layer.The coatings can protect Nb alloy effectively from oxidation at 1450℃ for at least 100 h,and dense SiO_(2)-B2O_(3) oxide scales are formed on the surfaces of the coatings.The presence of NbB in the interdiffusion zone effectively impedes the inward diffusion of Si in the coating during the oxidation process.
作者
张平
柯凯旋
陈成龙
陈正
任宣儒
冯培忠
Zhang Ping;Ke Kaixuan;Chen Chenglong;Chen Zheng;Ren Xuanru;Feng Peizhong(School of Material Science and Physics,China University of Mining and Technology,Xuzhou 221116,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2022年第3期997-1002,共6页
Rare Metal Materials and Engineering
基金
国家重点研发计划(2018YFB2001204)
国家自然科学基金(51601219)。
作者简介
Corresponding author:张平,男,1984年生,博士,讲师,中国矿业大学材料与物理学院,江苏徐州221116,E-mail:zhangping0095@cumt.edu.cn。
