This work explores experimentally the effects of DC electrical currents on lubricant film thickness alteration in lubricated sliding steel contacts in the boundary and mixed regime as measured by ultrasound.The experi...This work explores experimentally the effects of DC electrical currents on lubricant film thickness alteration in lubricated sliding steel contacts in the boundary and mixed regime as measured by ultrasound.The experiments were performed in a two-electrode cell-based pin-on-disk tester instrumented with ultrasonic transducers.Unelectrified and electrified tribological tests were conducted on steel flat-on-flat contacts under various speeds and loads using both a mineral base oil and a gear oil.Film thickness,coefficient of friction(CoF),and electrical contact resistance(ECR)were measured during short experiments(30 s)in unelectrified and electrified(1.5 and 3 A)conditions.The results suggest that film thickness,CoF,and all ECR are altered by passing DC currents through the contact.In particular,film thickness increased and decreased,respectively,by applying electricity at the different speeds and loads tested.These alterations were majorly ascribed to oil viscosity decrease by local heat and surface oxidation caused by electrical discharge and break down at the interface.展开更多
基金the financial support given by Tecnologico de Monterrey within the Challenge-based research project IJST070-23EG68001(call 2023)to carry out part of this research work.
文摘This work explores experimentally the effects of DC electrical currents on lubricant film thickness alteration in lubricated sliding steel contacts in the boundary and mixed regime as measured by ultrasound.The experiments were performed in a two-electrode cell-based pin-on-disk tester instrumented with ultrasonic transducers.Unelectrified and electrified tribological tests were conducted on steel flat-on-flat contacts under various speeds and loads using both a mineral base oil and a gear oil.Film thickness,coefficient of friction(CoF),and electrical contact resistance(ECR)were measured during short experiments(30 s)in unelectrified and electrified(1.5 and 3 A)conditions.The results suggest that film thickness,CoF,and all ECR are altered by passing DC currents through the contact.In particular,film thickness increased and decreased,respectively,by applying electricity at the different speeds and loads tested.These alterations were majorly ascribed to oil viscosity decrease by local heat and surface oxidation caused by electrical discharge and break down at the interface.