Multi-material bronze-steel plain bearings produced by laser-directed energy deposition

Purpose: This study aims to manufacture bimetallic bearings by achieving a sound deposition of bronze. Indeed, systems with rotating components use parts that reduce friction by allowing them to rotate freely. This is typically achieved with either rolling bearings or plain bearings. The last ones are usually made of self-lubricating materials, which may not excel in mechanical properties. An interesting alternative lies in bimetallic brass bearings, like bronze-steel combinations. However, they are limited in terms of available shapes and sizes due to challenges associated with the conventional manufacturing process. Design/methodology/approach: This study addresses the problems of mechanical weakness and production limitations of conventional brass bearings by introducing the use of Hybrid Manufacturing techniques: Laser Directed Energy Deposition technology in combination with five-axis milling. Specifically, Cu89Sn11 was deposited on a C45 substrate by varying the number of layers, and based on the results obtained, two kinds of bimetallic bearings were produced. Findings: The results of the one, two and five-layers samples indicate a sound deposition of Cu89Sn11, without defects such as detachments, cracks or porosities. The microhardness profile shows a decreasing trend from the substrate to the deposition zones. Bending and adhesion tests confirmed the excellent material bonding. Five-layers of Bronze were deposited on a C45 substrate to fabricate hemispherical and flat-face bearings. Originality/value: This study validates the feasibility of expanding the new class of 3D-printed high-performance materials, highlighting the advantages of additive manufacturing technologies, such as the design and material mixing freedom, by manufacturing two kinds of bimetallic bearings.