Microstructure and tribological behavior of the nickel-coated-graphite-reinforced Babbitt metal composite fabricated via selective laser melting

• Published in: International journal of minerals, metallurgy and materials Vol. 29; no. 2; pp. 320 - 326
• Main Authors: Zhao, Xingke, Hai, Xusheng
• Format: Journal Article
• Language: English
• Published: Beijing University of Science and Technology Beijing 01.02.2022; Springer Nature B.V; School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
• Subjects: Babbitt metal; Boundaries; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Coefficient of friction; Composite materials; Composites; Corrosion and Coatings; Friction; Frictional wear; Glass; Graphite; Laser beam melting; Lasers; Materials Science; Mechanical properties; Melting; Metallic Materials; Microcracks; Microstructure; Natural Materials; Nickel; Shear strength; Shear tests; Sliding friction; Surfaces and Interfaces; Thin Films; Tribology; lubricant additives; metal matrix composite; bearings; sliding wear; laser processing; fracture
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-020-2195-9

To improve the properties of Babbitt alloys, Ni-coated-graphite-reinforced Babbitt metal composite specimens were prepared via selective laser melting (SLM), and the composites microstructures, mechanical properties, and tribological properties were studied through scanning electron microscopy (SEM), shear testing, and dry-sliding wear testing, respectively. The results showed that most of the nickel-coated graphite (NCGr) particles were distributed at the boundaries of laser beads in the cross section of the SLM composite specimens. Microcracks and microvoids formed at the boundaries of laser beads where NCGr particles accumulated. Both the shear strength and the friction coefficient of the SLM composite specimens decreased with increasing NCGr content. The shear strength and the friction coefficient of the SLM composite sample with 6wt% NCGr were approximately 20% and 33% lower than those of the NCGr-free sample, respectively. The friction mechanism changed from plastic shaping furrow to brittle cutting with increasing NCGr content. A practical Babbitt material with a lower friction coefficient and sufficient strength can be obtained by controlling the NCGr particle dispersion; this can be achieved by choosing NCGr particles with a thicker Ni layer and precisely controlling the laser energy input during the SLM process.