Lubricity of environmentally friendly HFO-1234yf refrigerant

► Comparative study of HFO-1234yf and R-134a refrigerants was performed mostly on gray cast iron. ► Gray cast iron/gray cast iron and aluminum alloy/52100 steel interfaces were investigated. ► The new refrigerant HFO-1234yf exhibited excellent frictional and wear performance. ► SEM studies revealed the intact nature of the tribolayer in the presence of HFO-1234yf. ► XPS studies proved a fluorine-containing tribo-protecting layer on the topmost surface.