Influence of wollastonite shape and amount on tribo-performance of non-asbestos organic brake friction composites

In the present investigation, applicability of wollastonite as a potential non-asbestos based fibre/filler cum friction modifier is explored taking in to account the shapes of the wollastonite used for manufacturing the brake friction composite. Hence, brake friction composites containing wollastonite in the form of powder and fibres are prepared and characterized for their physical, mechanical and tribological properties. Experimental results indicated that wollastonite in the form of powder, improve the coefficient of friction and fade performance, whereas wollastonite in the form of fibres enhanced the wear and recovery performance of these brake friction composites. The wear surface morphology of the friction composites having wollastonite fibres aided in the formation of smooth contact plateaus which are in turn beneficial in decreasing the wear. From the study it is clear that not only judicious selection of ingredients for making brake friction composites is important but also their shapes help in formulating composites having desired friction and wear attributes.