Laser producing particulate reinforced Fe-based MMC coatings and industrial applications

Abstract

This paper presents the research achievements on Fe-based metal matrix composite coatings (MMC) on steel and iron substrates by laser alloying and laser cladding and their industrial applications. The high carbon-equivalent design ensures the good formability and high hardness while eliminates hot cracking during rapid solidification. The jointly adding of strong-carbide-formation-elements promotes the precipitation of large quantity of hard particles. The typical microstructure of the MMC coating characterizes about 4000∼5000/mm2 carbide particles (1∼3 micron in diameter) homogeneously precipitated on iron-base matrix. The average hardness of the coating reaches up to Hv0.2 950∼1050. Tribological test proved that this particulate reinforced Fe-based MMC coating posses excellent wear resistance and couple ability with various different frictional counterparts as well as remarkable decrease of the friction coefficient. Its grain-abrasion resistance is better than that of the plasma sprayed Mo coating and its adhesive-abrasion resistance better than the chromium coating. This MMC coating also demonstrated unique corrosion resistance and contact-fatigue resistance. This particulate reinforced MMC coatings have been successfully applied in rock arms, cam shafts, piston rings of engine, plunger pistons and kerf of cutting knives.This paper presents the research achievements on Fe-based metal matrix composite coatings (MMC) on steel and iron substrates by laser alloying and laser cladding and their industrial applications. The high carbon-equivalent design ensures the good formability and high hardness while eliminates hot cracking during rapid solidification. The jointly adding of strong-carbide-formation-elements promotes the precipitation of large quantity of hard particles. The typical microstructure of the MMC coating characterizes about 4000∼5000/mm2 carbide particles (1∼3 micron in diameter) homogeneously precipitated on iron-base matrix. The average hardness of the coating reaches up to Hv0.2 950∼1050. Tribological test proved that this particulate reinforced Fe-based MMC coating posses excellent wear resistance and couple ability with various different frictional counterparts as well as remarkable decrease of the friction coefficient. Its grain-abrasion resistance is better than that of the plasma sprayed Mo coating and i...