Study on mechanical and tribological properties of sintered metallic brake pad with different graphite, silicon carbide, and copper content

Abstract

Brake friction material is very important part in braking system where they use friction during braking process. The purpose of this research is to determine the optimal friction materials composition of sintered metallic brake pad for wind turbine braking system. The utility of sintered metallic brake pad for wind turbine application is increases rapidly now a day, so the performance of brake pads and their life of operation matters a lot. Hence, the purpose of this research is to improve the wear properties of sintered metallic brake pad by changing their chemical composition. Three different testing which are density and, shore hardness test and wear test and microstructure evaluation were done in order to select which metal is the most suitable for wind turbine application. Three different samples(S-01, S-02, S-03) with different compositions of graphite, silicon carbide (SiC) and copper content were prepared for this study to determine the optimal properties with lower wear rate. Sample S-01 prepared with basic formulation, contained (Fe-70%, SiC-8%, Graphite-12%, BaSO4 -6%, Sn-4%).Sample S-02 prepared with an decreased graphite containedcompare to S-01 ,it contained ( Fe-70%,SiC-10%, Graphite-10%, BaSO4 -6%, Sn-4% ). Sample S-03 further modified with an addition of copper content in the mixture formulation by adjusting the compositions of other additives, S-03 contained ( Fe-60%,Cu-10%, SiC-10%, Graphite-10%, BaSO4 -6%, Sn-4% ). The selected materials were mixed and compacted into desired mould with 510 MPa of pressure. The compacted samples were sintered at the sintering temperature of 1000oC. These samples were tested for wear test, hardness test & subjected to density measurement and microstructure evaluations. Results shows that sample S-02 have improved wear properties as compare to S-01 due to a decrease in graphite content and an increase in barium sulphate, while sample S-03 gave superior wear properties than S-02, this is due to an increase in copper content which results in faster heat dissipation rate because of its higher thermal conductivity.