Tribological exams had been performed employing a ball-on-disc T-11 tester. The balls were product of metal, While the discs have been product of metal, aluminium oxide, zirconium oxide, polyamide and poly(methyl methacrylate). The outline of the gadget as well as solutions has long been specified during the literature (Szczerek and https://friedrichw789peb5.wikicorrespondent.com/user