Controlling the tribology performance of gray cast iron by tailoring the microstructure

Addition of rare metal is an interesting way of microstructural controls. Herein, this study employed niobium to tailor the microstructure of gray cast iron, and further to control the tribology properties. Four casting discs with various niobium contents (0~0.31wt.%) were prepared to slide against one certain resin-based friction material. Friction test was performed on a 1:5 scale brake inertia dynamometer under different conditions. Results revealed the significance of niobium concentration on the microstructure by influencing the solidification process. Consequently, a modification to the mechanical and thermal properties was achieved, which was responsible for subsequent tribology behavior. Overall, 0.20wt.% was defined as the optimized formulation of a lower sensitivity to operating conditions, higher brake efficiency, and higher wear resistance. •Microalloying element niobium addition was used to tailor the microstructure of gray cast iron.•Role of niobium addition in tribology performance of gray cast iron matched with resin based friction material was studied.•The relationship between physical properties (mechanical and thermal properties) and tribology performance was developed.•The sensitivity to speed/load/temperature was explored.•The tribology behavior was studied by analyzing the worn surfaces of friction couples.