This grant provides funding to develop new methods for machining elastomers and elastomer-steel composites. Several machining methods will be investigated including high speed milling using ultra-sharp cutters, machining of elastomers with induction heated tools, and machining of cryogenically-cooled elastomers. An understanding of the tool-workpiece interaction will be developed using finite element techniques that address the large strain and highly deforming elasto-viscoplastic response of elastomers. The models will be used to determine tool forces, workpiece temperatures and deformation, and surface roughness of a machined elastomer as a function of operating conditions and tool geometry. Appropriate material property data will be developed in close collaboration with several industrial partners to characterize the elastomer response at the elevated temperatures and high strain-rates anticipated in machining. Tools and operating conditions that result in smooth surface finishes and damage-free parts will be identified, and cutting tests will be performed to verify the models based upon tool forces and surface finish.
This research will lead to new understanding of the fundamental mechanisms of chip formation during machining of elastomers at both elevated temperatures and cryogenic conditions. This understanding is critical for identifying tools and operating conditions to improve the machinability of a wide range of elastomeric products such as shock isolators, sound and vibration absorbers, seals, tires, electrical and thermal insulators, footwear, tubing, and other applications requiring a highly flexible or stretchable material. As compared with traditional expensive and time-consuming molding processes, the machining methods investigated in this research promise a practical alternative for rapid production of precision elastomeric parts for a multitude of custom applications at significantly lower cost. This research also offers the potential for the development of new manufacturing processes for cost-effective and environmentally conscious tire recycling.
