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Abstract No.: |
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Title: |
Correlation between high temperature wear of NiAl intermetallic and stellite 6 PTA coatings
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Authors: |
Ana Sofia d'Oliveira / Federal University of ParanĂ¡ - UFPR, Brazil Cristiano Brunetti / PG-Mec/UFPR, Brazil Rafael Gomes/ PIPE/UFPR, Brazil Giuseppe Pintaude/ UTFPR, Brazil
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Abstract: |
Cobalt-based alloys are widely used in high temperature applications because of their superior wear resistance and thermal stability. Another class of high temperature materials are the Ni-Al intermetallic alloys. However, the response to wear at elevated temperatures of both alloys is not well understood. This study aims to characterize Plasma transferred arc coatings processed with a powder mixture of Ni-20wt%Al and with the Stellite 6 alloy. The coatings were processed on an AISI 1020 steel substrate using two deposition currents (70 and 120 A) and a constant volume powder feed rate. Coatings microstructure was assessed by optical and scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. High temperature sliding wear tests and instrument indentation, the latter to determine young modulus (E) and microhardness (H) of coatings. A dendritic solidification structure was observed for both deposition current in Stellite 6 coatings, while a dendritic and columnar solidification structure developed for Ni aluminides coatings processed with 70 A and 120 A, respectively. The relation between E/H and high temperature wear was analyzed. High temperature wear tests suggest that there is a close relationship between microstructure and wear behavior at high temperature.
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