Development of Lead-Free Copper Alloy Graphite Castings
The purpose of this project is to enhance the foundry technology of lead-free machinable castings made from copper alloys containing dispersed graphite.
UWM has made several accomplishments in their research. Researchers have designed and fabricated three kinds of stirrers to achieve homogeneous distribution of graphite in the liquid copper alloys. They fabricated a variable speed unit to synthesize the composite and conducted experiments to decide the best possible stirrer out of the three kinds that were designed.
Researchers optimized synthesis and centrifugal casting parameters to successfully segregate the graphite particles to the inner areas of castings which are needed in cylindrical plumbing and bearing applications. They also identified that the presence of graphite particles in the inner area of a casting decreases the wear rate and friction coefficient against cast iron. Researchers identified that the presence of graphite particles in the matrix decreases the chip size and cutting force. In addition, they determined that the higher applied load, the graphite particles reduces the friction coefficient more effectively than lead in the copper alloy, running against steel counterface.
UWM has sent samples for testing bearing properties of copper-graphite alloys to several industries. Initial testing results from some industries appear very promising.