Park, SimonZafar, Talha2023-09-282023-09-282023-09-21Zafar, T. (2023). Laser treatment of asphaltene based carbon fibers (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.https://hdl.handle.net/1880/11721310.11575/PRISM/42055Carbon fiber is a lightweight, high tensile strength, and high modulus material extensively employed in diverse industries such as aerospace, automotive, and energy. Its production involves the utilization of various precursors tailored to specific applications, based on desired mechanical properties. However, the widespread adoption of carbon fiber is hindered by manufacturing costs and associated emissions. Notably, the pre-treatment of precursors, melt spinning, stabilization, carbonization, and graphitization steps contribute significantly to costs, energy consumption, and greenhouse gas emissions. Consequently, there is a need for cost-effective processing techniques to meet the increasing demand for carbon fiber. This research focuses on the use of asphaltene derived from Alberta oil sands as a low-cost alternative precursor, specifically exploring the graphitization step in carbon fiber manufacturing. In the conventional method, graphitization is conducted using a furnace between 2000 °C and 3000 °C. In this study, the potential use of laser technology as an alternative heat treatment source is proposed due to its rapid and high energy generation capabilities. Laser treatment generates energy measured above 2000 °C using a pyrometer, by adjusting scan speed, laser power, and treatment direction, different temperature profiles are obtained. Graphitized asphaltene-based carbon fiber exhibits an enhanced strength-to-weight ratio, improved thermal stability, increased mechanical stiffness, higher corrosion resistance, and enhanced electrical conductivity. X-ray diffraction analysis is employed to understand crystalline growth and interlayer spacing (d002), while Raman spectroscopy provides insight into chemical structure transitions on the fiber surface. Scanning electron microscopy (SEM) is utilized to observe surface morphology pre- and post-laser treatment at a microscopic level. Electrical conductivity tests are conducted to evaluate the impact of laser treatment on the carbon fiber's electrical resistivity. Additionally, mechanical testing is employed to assess the strength of laser-treated carbon fiber. Multiphysics finite element analysis is utilized for modeling laser treatment, allowing an understanding of the required temperature (above 2000 °C) represented by a distributed heat flux on the fiber's surface. This study explores alternative and cost-effective manufacturing approaches for carbon fiber by utilizing asphaltene as a precursor and employing laser technology for the graphitization process. The results offer valuable insights into the structural and performance enhancements achieved, facilitating carbon fiber production technique advancements.enUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.carbon fiberAsphalteneLaserGraphitizationEngineering--Mechanicalmaster thesis