ABSTRACT

The purpose of this research is to observe the effects of normal load in tribological properties of cast iron. The flake, vermicular and nodular graphites are used as microstructure variations in this research. The wear tests carried out with pin-on-disc type tribometer. The results of this study are used as comparison which are the best material for train brake’s block.

This research used 0.5, 1 and 1.5 MPa as load variations. The tribological properties are friction coefficient (μ) and the wear area in volume unit. The temperature of 1.5 MPa test specimens are recorded. The results of this research are (1) the higher the pressure (load) is given, the friction coefficient of cast iron will decrease. The value of the friction coefficient are 0.445, 0.431 and 0.415 for flake, vermicular and nodular graphite respectively. (2) the higher the pressure (load) is given, then the wear volume will increase too. The largest wear volume occured in the flake graphite, the smallest wear volume occured in the nodular graphite, and the wear volume of vermicular graphite is between them. (3) The lowest temperature is recorded in the flake graphite, the highest one is recorded in the nodular graphite, and the temperature of vermicular graphite is between them.

Keywords : tribology, wear, cast iron, graphite, flake, vermicular, nodular