Bimodal Particle Reinforcement for Wear Resistant Powder Metallurgy Steels

Abstract:

Reinforcement of powder metallurgy steels with fused tungsten carbide (FTC) has been shown to improve the wear resistance under certain loading conditions. A weakness is however the low hardness of the matrix, which results in selective wearing of the matrix between the carbide particles, i.e. “washing-out” effects. In the present study, in a first round fine metallic or carbidic particles were added to the iron-graphite powder mix, and the blends were die compacted and sintered in protective atmosphere. The specimens were then tested under different wear loads. It showed that also metallic powders added were transformed into carbides during sintering, thus resulting in reinforcement by fine carbides. Since Mo alloying proved to be most effective with regard to hardness and strength, specimens Fe-3%Mo-0.8%C reinforced with 20% coarse FTC (all in mass%) were sintered and tested according to ASTM G65, Continuous Impact Abrasion and dry sliding against ball bearing steel. It showed that Mo addition had quite pronounced positive effect on the G65 erosion resistance and, somewhat less, on dry sliding, while wear resistance in CIAT was less affected; the basic wear mechanisms however remained unchanged.

• Periodical: Materials Science Forum (Volumes 825-826)
• Pages: 1001-1008
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.825-826.1001
• Online since: July 2015
• Authors: Antonio Gianessi, Christian Gierl-Mayer, Herbert Danninger*
• Keywords: Particle Reinforcement, Powder metallurgy, Steels, Wear Resistance

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