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| Abstract No.: |
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Scheduled at:
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Tuesday, May 04, 2010, Hullet Room 12:20 PM
Wear Protection 2
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| Title: |
Development and characterization of amorphous steel base cermets
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| Authors: |
Maria Parco* / INASMET-TECNALIA , Spain
Ignacio Fagoaga / Inasmet Tecnalia, Spain
Georgiy Barykin/ Inasmet Tecnalia, Spain
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| Abstract: |
Due to their outstanding wear properties, tungsten-carbide base cermets have been extensively used to protect components against harsh abrasive and erosive service conditions. The high carbide contents prevent erosive and also abrasive attack as they make coatings hard. In contrary, cermet coatings with high carbide contents become very ineffective in preventing wear by impact and the high production costs associated to the finishing steps, when required, used to make this technology prohibitive for large components. On this regard, nanostructured/pseudo amorphous steels represent a revolution in material science because they are iron-based materials with strengths up to four times that of current steels and with outstanding corrosion resistances.
This work deals with the development of a new family of cost effective wear and corrosion resistant coatings based on a nanostructured/ pseudo amorphous steel matrix reinforced with tungsten carbide. As spray process, the recently introduced oxy-fuel ionisation (OFI) system was used. The OFI process is basically a high velocity combustion process able to operate within the super-sonic regime using a broader range of fuel/oxidant ratios than conventional HVOF guns. The incorporation of a low energy plasma jet in the first stage of the gun, allows the continuous addition of ionised and heated gas species to the combustion chamber, thus assisting/enhancing the combustion process and broadening its stability over a large range of gas mixtures. The coatings have been developed using commercial amorphous steel and carbide based cermets powders as feedstock material. The spray parameters were optimised to obtain a dense and homogeneous microstructure, with different contents of the reinforcing phase. The resulting coatings have been characterised in terms of their sliding wear resistance and corrosion performance.
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