The recently introduced environmental legislation in the federal states of California and Washington (US) has put the role of copper powder in organic-based, asbestos-free, brake pads for passenger cars into question. The unique combination of properties granted by copper during braking - efficient heat removal, stabilization of friction behaviour, noise reduction, and low wear of both pad and disc -makes its substitution a challenging effort, since no other affordable metal represents a valid "one to one" alternative. This research presents a joint effort on the way to innovative copper-free formulation. Experimental brake pads with different combination of metallic powder for copper replacements were prepared and fully characterized in their physical, thermal and mechanical properties. Friction surfaces of pads and discs were investigated through Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Focused Ion Beam (FIB) analysis and roughness profiles. Friction behavior was assessed using AK-Master test procedure, determining the influence of speed, pressure and temperature on the friction coefficient and fade resistance/recovery. The acquired insights were then exploited to re-formulate current copper-based industrial mixes, trying to create a sound copper-free alternative.
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