FORMATION MECHANISM OF SILICON MODIFIED ALUMINIDE COATING ON A NI-BASE SUPERALLOY
سال انتشار: 1387
نوع سند: مقاله ژورنالی
زبان: انگلیسی
مشاهده: 857
فایل این مقاله در 6 صفحه با فرمت PDF قابل دریافت می باشد
- صدور گواهی نمایه سازی
- من نویسنده این مقاله هستم
استخراج به نرم افزارهای پژوهشی:
شناسه ملی سند علمی:
JR_IJIEPR-19-5_004
تاریخ نمایه سازی: 7 شهریور 1393
چکیده مقاله:
Formation mechanism of silicon modified aluminide coating applied on a nickel base super alloy IN-738 LC by pack cementation process was the subject of investigation in this research. Study of the microstructure and compositions of the coating was carried out, using optical and scanning electron microscopes, EDS and X-ray diffraction (XRD) techniques. The results showed that due to low partial pressure of silicon halide in Pack process, the amount of soluble silicon in the coating can not exceed 1 wt % of the total coating composition, although the Si content of the particles present within the outer coating sub-layer could reach as far as 5 wt%. Thus, the small amount of soluble Si within the coating could not provide the necessary conditions for formation of any intermetallic and it seems that the formation and growth behavior of various sub-layers in Si-modified aluminide coating is similar to that of simple aluminide coating. Three sub-layers were detected in the coating structure after being subjected to diffusion heat treatment. They were an outer Ni-rich NiAl sub-layer; a middle Ni-rich NiAl and an inter diffusion sub-layers. The details of formations and growth mechanism of these sub-layers has been discussed in this research.
کلیدواژه ها:
Aluminizing ، Si-Modified Coating ، NiAl Phase ، Formation Mechanism ، Pack Cementation ، Low Temperature High Activity ، Halide
نویسندگان
H. Arabi
Professor, Department of Materials & Metallurgical Engineering, Iran University of Science & Technology, Tehran-Iran.
S. Rastegari
Assistant Professor, Department of Materials & Metallurgical Engineering, Iran University of Science & Technology., Tehran-Iran,
Z. Salehpour
Research assistant, Department of Materials &Metallurgical Engineering, Iran University of Science & Technology, Tehran-Iran,
A. Bakhshi
MSc. Student, Department of Materials & Metallurgical Engineering, Iran University of Science & Technology, Tehran-Iran,