Characterization of Iron Aluminide Diffusion Coatings Obtained after Friction Surfacing
Norberto Martins,
Ana Paula Silva,
Gilmar Cordeiro da Silva,
Ítalo Bruno dos Santos,
Carlos Eduardo dos Santos,
Fernanda Troysi,
Pedro Brito
Affiliations
Norberto Martins
Graduate Program in Mechanical Engineering, Pontifical Catholic University of Minas Gerais, Av. Dom José Gaspar 500, Belo Horizonte 30535-901, MG, Brazil
Ana Paula Silva
Graduate Program in Mechanical Engineering, Pontifical Catholic University of Minas Gerais, Av. Dom José Gaspar 500, Belo Horizonte 30535-901, MG, Brazil
Gilmar Cordeiro da Silva
Graduate Program in Mechanical Engineering, Pontifical Catholic University of Minas Gerais, Av. Dom José Gaspar 500, Belo Horizonte 30535-901, MG, Brazil
Ítalo Bruno dos Santos
Graduate Program in Mechanical Engineering, Pontifical Catholic University of Minas Gerais, Av. Dom José Gaspar 500, Belo Horizonte 30535-901, MG, Brazil
Carlos Eduardo dos Santos
Federal Center for Technological Education of Minas Gerais, Av. Amazonas 5253, Belo Horizonte 30421-169, MG, Brazil
Fernanda Troysi
Faculty of Sciences and Technology, Federal University of Goiás, Rua Mucuri, Parque Itatiaia, Aparecida de Goiânia 749687-55, GO, Brazil
Pedro Brito
Graduate Program in Mechanical Engineering, Pontifical Catholic University of Minas Gerais, Av. Dom José Gaspar 500, Belo Horizonte 30535-901, MG, Brazil
Iron aluminides are considered as candidate materials for high temperature applications for their excellent high temperature corrosion and oxidation resistance. In the present work, iron-aluminide coatings were developed by friction surfacing (6351 aluminum alloy deposited on a low-carbon steel substrate) followed by a diffusion heat treatment. The initial coatings were found to be geometrically homogenous and adhered well to the steel substrate. The heat treatment process was carried out at 550 °C for 48, 72 and 96 h and the resulting coatings were characterized in terms of microstructure, chemical composition, hardness distribution and phase composition. After heat treatment, the coating/substrate interface morphology was modified and presented patterns typical of Fe-Al intermetallic formation, as well as a substantial increase in hardness (>900 HV) relative to the initial as-deposited condition. With the diffusion treatment, initially Fe2Al5 was found to develop in the coatings, which was converted into FeAl2 after longer exposures.
