Optimization of steel wool contents in non-asbestos organic (NAO) friction composites for best combination of thermal conductivity and tribo-performance

The brake-pads were tested for their friction and wear behavior on a Krauss type RWDC 100, 450 V/50 Hz machine in simulated braking condition against a cast iron commercial disc and evaluated as per ECR 90 test schedule. It was observed that with increasing metal contents, mechanical properties decreased, TC increased slowly and other important friction properties including fade resistance improved. Wear properties however, did not show any correlation with amount of steel wool, TC or mechanical properties. Overall, composite S3 proved to be the best performer. SEM studies proved helpful in understanding the wear mechanism.