Tribological behavior of T-401/tin–bronze composite coating deposited by HVOF on the bushing of planet journals

Lead-containing tin–bronze is one of the materials commonly used for journal bearings. However, due to the inherent toxicity of lead, environmental regulations around the world have been targeted to eliminate the usage of lead-containing bearing materials. To this end, a novel lead-free journal bearing material has been developed, which is a tin–bronze-based composite with Tribaloy alloy T-401 additive. This article presents a study of tribological behavior of this new material coated on the bushing of planet journals. The coating is deposited on the bushing using the high velocity oxygen fuel (HVOF) thermal spray technique. The tribological properties such as friction and wear resistance of the coated bushing are investigated under the WAMsc3 Sliding Contact Test, along with the lead-containing tin–bronze bushing tested for comparison. The test results show that the T-401/tin–bronze bushing runs longer than the lead–tin–bronze bushing before the friction coefficient reaches 0.5. The T-401/tin–bronze bushing also exhibits higher wear resistance and higher contact stress compared to the lead–tin–bronze bushing.