Investigation of SnSbCu coatings, electrodeposited on bronze and copper

The soft white anti-friction alloys on tin and lead-based, so-called babbitt metal are widely used bearing materials. The highest operability has multilateral sliding bearings, obtained by casting molten babbitt into the body from a variety of metals and alloys. However, it is known that the fatigue strength of babbitt increases with decreasing thickness so thin layers in many cases may be more effective. One way of obtaining thin layers is electrodeposition. Electrodeposition allows you to manage the process of structure formation and has no negative effects on the substrate. The chemical composition and microstructure of the coatings representing ternary alloy SnSbCu were examined using scanning electron microscopy (SEM) and X-ray diffraction (XRD). These coatings were prepared in the process of electrodeposition on a copper and bronze substrate. Wear was determined by weight loss in the boundary lubrication regime. The wear intensity was calculated by differentiating the curves of weight loss (dG/dL). It was established that uniform coating of the dark colored needles forms on copper and bronze substrate, presents a solid solution of antimony and copper in the tin, in which are uniformly distributed large bright crystals of Sn3Sb2 (up to 1 mm) compound. X-ray analysis also showed that in the studied surfaces present the same phase (Sn3Sb2, Cu6Sn5), as in the most widely used alloy babbitt B83 (Sn11Sb5.5Cu). Wear test showed that the obtained coatings significantly reduce the wear intensity of copper and bronze, as at the running-in stage and at the stage of steady wear.