Experimental Investigation of Semi-metallic Disc Brake Materials

An orthogonal experimental design,combining with Chase friction testing was used to obtain a semi-metallic disc brake material formula with less effect of temperature,load and velocity on friction coefficient and wear.The average friction coefficient was 0.444.Experimental results show that black iron oxide,a mild abrasive,affected greatly on the standard deviation of friction coefficient relevant to temperature among the four ingredients.This is because that black iron oxide increased the friction at the low temperature at the beginning,but it decreased it when the temperature was high.Excessive aluminium oxide,a strong abrasive,was used to induce the increase of friction coefficient and specific wear rate and the occurrence of over recovery,especially friction coefficient was increased with load,while excessive mixed lubricant containing graphite and antimony trisulphide reduced friction coefficient and specific wear rate.