Field aided technology for local micro-tailoring of polymeric composites with multi-functional response.

摘要

Field-aided micro-tailoring (FAiMTa) technology provides ability to modify the distribution and orientation of inclusions in polymeric composites. This technology enables a new kind of functionally graded materials whose structure is designed, optimized and micro-tailored for an intended multifunctional application. This technique also enables orthotropic composites with inclusions that are unavailable as traditional fibers or are highly expensive in fibrous form. Applying an electric field to a liquid suspension causes a redistribution of the inclusions, arranges them in chain-like structures and/or orients fibrous inclusions or chain-like structures along the field. Properties of resulting cured composite can vary from the point to point in accordance with the design objective. The thesis outlines the process requirements of the field-aided technology, analyzes physical mechanisms influencing the microstructure in an electric field and provides experimental validation of feasibility FAiMTa technology. Theoretical analysis captures the prevalent mechanisms of field-aided macro-tailoring which is verified by direct observations. Mechanical and thermal properties of orthotropic and random composites containing glass-fiber, ceramic and graphite particles in an epoxy are measured. Results of electroactive testing of iron/silicone, alumina/silicone and ceramic/silicone composites modified by FAiMTa technology for self-sensing and actuation applications are presented.