Graphite Melting Behavior

An experimental program was conducted to determine the melting behavior of graphite. Data was obtained with an electric arc heater, and a resistance heater over a pressure range from the triple point to approximately 320 atmospheres. Temperature measurements were made in the arc heater environment with a scanning spectrometer while a recording optical pyrometer was used for the resistively heated specimens. ATJS and pyrolytic graphite were the test materials and argon and nitrogen were the test gases. Within the accuracy of the data the results did not show any discernible difference with gas environments. Arc heater data showed a slight increase in melting temperature over that exhibited by the resistively heated models. Values for the triple point were determined to be 102 atmospheres pressure with temperatures varying between 4100K and 4300K depending upon mode of heating and material.