Carbon fiber growth kinetics and thermodynamics using temperature controlled LCVD Original Research Article

The chemical kinetics of carbon fiber deposition using Laser Chemical Vapor Deposition (LCVD) was studied. Using methane as the precursor at a total pressure of 78.4 kPa, the activation energy was 176 kJ/mol and the order of the reaction was 3.47. Using propylene as the primary reagent at a total pressure of 21.3 kPa, the activation energy was 286 kJ/mol and the order of the reaction was 1.90. The values are based on measured temperatures ranging from 1720 to 2170 °C. The cause of volcano shaped deposits was also explored through experimentation and thermodynamic modeling, and found to be an etching reaction induced by the elevated temperatures at the center of the laser spot.