A round robin on combined electrochemical and friction tests on alumina/stainless steel contacts in sulphuric acid

A round robin on tribo-electrochemical measurements was organised by the Tribology Committee of the CEFRACOR. Seven European laboratories participated in this round robin aimed at evaluating the reproducibility and comparability of experiments. The electrochemical and tribological behaviour of an Al2O3 ceramic sliding against a 316L stainless steel was determined in sulphuric acid according to a previously defined procedure. The recommended procedure describes the surface preparation, the electrochemical treatment and the operating conditions of load, velocity, frequency and sliding time. The following experiments were performed: polarisation curves, polarisation curves during rubbing, friction test, friction test at an applied electrochemical potential. The reproducibility at laboratory level was good for both tribological (friction, wear) and electrochemical parameters. The convergence of the electrochemical measurements among different laboratories was satisfactory and not affected by simultaneous rubbing. The participants, despite the large differences in tribometer design used, found a good agreement for the coefficients of friction. The extent of scattering on wear results depends on the quantification criterion used. The concept of dissipated energy allows one to compare and to rationalise the wear results obtained using different tribometers.