Microstructure and Oxidation Resistance of an Aluminide Coating on the Nickel Based Superalloy Mar M247 Deposited by the CVD Aluminizing Process

Archives of Metallurgy and Materials

M. Zielińska¹  R. Filip²  M. Zagula-Yavorska²  J. Sieniawski² 

[1] MTU AERO ENGINES POLSKA, RZESZÓW;RZESZÓW UNIVERSITY OF TECHNOLOGY, FACULTY OF MECHANICAL ENGINEERING AND AERONAUTICS, 2 W POLA STR., 35-959 RZESZÓW, POLAND

关键词: Keywords: Mar M247 Ni-base superalloy;    CVD method;    aluminide coating;    oxidation resistance;   

DOI  :  10.2478/amm-2013-0057

学科分类：金属与冶金

来源: Akademia Gorniczo-Hutnicza im. Stanislawa Staszica / University of Mining and Metallurgy

【 摘 要 】

An investigation was conducted to synthesize βNiAl coating on the nickel based superalloy Mar M247 in a chemical vapor deposition process (CVD). The low activity process of aluminizing was carried out for 8 hours at the temperature 1050°C. Surface morphology and cross-section microstructure of the diffusion coating were studied and compared by using an optical microscope, a scanning electron microscope (SEM) equipped with energy dispersive spectroscopy and an X-ray diffractometer. It was found that aluminide coating with the thickness of 37 μm consisted of two layers: an outer one and the inner interdiffusion one. The outer layer consists of single phase βNiAl. The inner one, consisted of βNiAl phase and carbides: MC and M23C6 types which were originally present in the substrate. Cyclic oxidation test was performed at 1000°C for 1000h in the air atmosphere. The aluminized samples exhibited a small mass increase and the α- Al2O3 oxide formed during oxidation test had a good adherence to the coating. The decrease of aluminum content in the coating with the prolongation of the oxidation time and the phase transformation of βNiAl to γ’ Ni3Al and to γNi solid solution were observed. The samples without the coating showed a strong mass decrease in comparison to the coated samples.

【 授权许可】

Unknown