包埋渗铝法制备Fe-Al渗层及其扩散机制  

Preparation Method and Diffusion Mechanism of Fe-Al Coating on Q235 Low Carbon Steel by Pack Aluminizing

作　　者：李宁宁 陈旸 陈希 殷利迎 陈光[2] LI Ningning;CHEN Yang;CHEN Xi;YIN Liying;CHEN Guang(School of Materials Science and Engineering,North China University of Water Resources and Electric Power,Zhengzhou 450045,China;MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials Technology,Engineering Research Center of Materials Behavior and Design,Ministry of Education,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]华北水利水电大学材料学院,郑州450045 [2]南京理工大学先进金属与金属间化合物材料技术工信部重点实验室材料评价与设计教育部工程研究中心,南京210094

出　　处：《材料研究学报》2021年第8期572-582,共11页Chinese Journal of Materials Research

基　　金：国家自然科学基金(51571117,51731006,51771093,91860104);华北水利水电大学高层次人才科研启动项目(4001/40680)。

摘　　要：包埋渗铝法可在钢基体表面制备出一层致密、坚固、连续的Fe-Al渗层,以改善基体性能。本文在不同温度和不同时间下对Q235低碳钢进行包埋渗铝,形成Fe-Al渗层,采用X射线衍射、扫描电镜及能谱分析等方法研究了渗铝层的物相结构、表面及截面形貌和成分,采用显微硬度仪测量了截面硬度。结果表明,不同渗铝温度下获得的渗铝层,主要含有Fe_(2)Al_(5)和FeAl_(3)两相,且750℃得到的渗层存在较多Fe_(2)Al_(5)相;随着渗铝温度升高,Fe-Al渗层厚度增加,Al原子扩散系数增大,但显微硬度降低;不同渗铝时间下制备的渗铝层,物相仍以Fe_(2)Al_(5)和FeAl_(3)为主,但随着渗铝时间延长,FeAl_(3)含量减少,且Al原子扩散系数变大,渗层显微硬度略有降低。在进一步分析Fe-Al渗层形成的热力学与动力学基础上,总结了渗铝层形成的扩散机制。The Fe-Al coating,with compactness,stiffness,and continuity,could be prepared on Q235 low carbon steel by pack aluminizing.The phase structure,morphology,composition,and hardness of the prepared coating were characterized by XRD,SEM,EDS,and micro-hardness tester respectively.Results indicate that the Fe-Al coating is composed of Fe_(2)Al_(5) and FeAl_(3) phases,whilst,the coating fabricated at 750℃is particularly rich in Fe_(2)Al_(5) phase.With the rising temperature,the thickness of Fe-Al coating increases,whereas the micro-hardness decreases.As a result of aluminizing for different time,the formed coatings are composed of the two phases Fe_(2)Al_(5) and FeAl_(3) as well.However,with the increasing aluminizing time,the content of FeAl_(3) phase decreases,while the micro-hardness of the coating decreases slightly.Finally,a diffusion mechanism related with the formation of Fe-Al coating is proposed based on the comprehensive analysis on the thermodynamics and kinetics of pack aluminizing process.

关 键 词：金属材料 FE-AL 渗层 包埋渗铝法 扩散系数 显微硬度 

分 类 号：TG131[一般工业技术—材料科学与工程]