M. Yamada, J. Wakabayashi, M. Fukumoto, Toyohashi University of Technology, Toyohashi, Aichi, Japan; J. Kitamura, Fujimi incorporated, Kakamigahara, Japan
Molybdenum disulfide (MoS2) is widely used for structural components in order to improve friction property. However, it is difficult to fabricate MoS2 coatings by conventional thermal spray processes due to thermal decomposition of MoS2 feedstock powder during spraying. In this study, copper (Cu) / MoS2 composite coatings were fabricated by cold spray method. In order to fabricate the composite coatings, composite powders were fabricated by agglomeration method and mechanical milling (MM) with changing MoS2 concentration and milling time. It was possible to fabricate Cu/MoS2 composite powders both agglomeration and MM methods. However it was difficult to fabricate the coatings by cold spray with using agglomeration powders with weak bonding of each particle. Cu/MoS2 composite coatings were successfully fabricated with using MM powders. It became clear that increase the concentration of MoS2 in the coating decrease the friction coefficient. However, higher amount of MoS2 decreased deposition efficiency of particles during spraying and increased abrasion loss. The ideal concentration ratio of MoS2 particle is lower than 5wt.% upon fabrication of Cu/MoS2 coatings by cold spray. It was possible to enhance the hardness and wear resistance of the coatings by increase the milling time of feedstock powders. Therefore, Cu/MoS2 composite coating with good friction property can be fabricated with controlling feedstock powder.
Summary: Copper(Cu) / Molybdenum disulfide (MoS2) composite coatings were fabricated by cold spray method. In order to fabricate the composite coatings, composite powders were fabricated by agglomeration method and mechanical milling (MM) with changing MoS2 concentration and milling time. Cu/MoS2 composite coatings were successfully fabricated with using MM powders. It became clear that, Cu/MoS2 composite coating with good friction property can be fabricated with controlling feedstock powder.
