Optimization on tribological properties of aramid fibre and CaSO4 whisker reinforced non-metallic friction material with analytic hierarchy process and preference ranking organization method for enrichment evaluations

This paper develops an evaluation method based on the analytic hierarchy process (AHP) and preference ranking organization method for enrichment evaluations (PROMETHEE) in order to select the optimal material according to several criteria which are probably conflicting. The material formulations, which were non-metallic friction material modified with aramid fibre and CaSO4 whisker by different weight, were designed based on the quasi-level uniform method and the friction test results in three typical conditions were considered as criteria for the performance assessment. By AHP, the subjective judgments of evaluators are quantified as the weight for each criterion, while PROMETHEE is employed to determine the complete ranking of the alternatives. Moreover, further results can be obtained from the application of geometrical analysis for interactive assistance (GAIA). The results show that the formula of 70 wt.% NBR modified PF with 12 wt.% CaSO4 whisker and 4 wt.% aramid fibre exhibits the optimal properties.