Sheared Metal-Carbon Composite Conductors

Carbon-metal composites (CMC - metals infused with carbon) have shown increases in electrical and thermal conductivities compared to pure metals, but experimental results are inconsistent. For example, electrical conductivity increases for CMC vary considerably. The proposed work aims to both improve and bring consistency to CMC conductor properties. How this problem is being addressed: The team (SFI and PNNL) will develop a new approach for manufacturing high-strength, enhanced-conductivity metal-carbon composites suited for wire and bulk component manufacturing. It is anticipated that the new approach will improve the conductivity, creep resistance, and strength of Cu with the addition of graphene. Applications include aircraft wiring, electrical vehicle motor windings, and power electronic circuits. Phase I Work: In Phase I of the STTR, we will utilize a combination of modeling and advanced characterization to identify the key microstructural features driving conductivity improvements and identify paths towards further enhancements. A combination of higher and lower cost methods will be used to generate conductor wires. Initial modeling will include the application of the multi-scale conductor FEA and MD architectures developed by PNNL. Phase I characterization will focus on electrical conductivity (PNNL CABLE setup) with additional investigation of mechanical properties, grain structure, and chemical distribution. Shear Form, Inc will apply thermal and mechanical processing and perform basic mechanical testing. PNNL will perform both modeling and characterization to identify structure-property relationships. This technology should be applicable to multiple areas with simultaneous strength, conductivity, and creep resistance requirements. Phase II Work will include 1) fabrication of equipment needed to produce prototype CMC conductor wire using a continuous process, 2) refine the conductor modeling for accuracy 3) comparison of CMC materials to current materials, 4) simultaneous refinement and upscaling the modeling, optimizing carbon form, fraction, and distribution relationships, 5) Feed resulting parameters into integrated computational materials engineering (ICME) modeling for further enhancement. Collaboration with PNNL will be ongoing to leverage PNNL’s modeling and testing technologies. Commercial Applications and Other Benefits: The technique and knowledge developed in the proposed work will be applicable to many metals. This modeling technology can be applied to make improved electrical transmission lines, heat exchangers, strengthened metal part designs, and many other applications.