Carbon deposition on Fe, Ni, and Cr and their alloys in supercritical jet fuel environment

The formation of carbon deposits on metal surface from carbon decomposition of jet fuel is an important issue in the development of advanced aircraft where the fuel is also used as a heat sink. The carbon and sulfur based solid deposit formation from jet fuel JP-8 stressing on pure Ni, Fe, and Cr and binary alloys of Fe/Ni (55/45), Fe/Ni (64/36), and Ni/Cr (80/20) surfaces was studied. The catalytic effect of Ni and Fe surfaces resulted in a significant amount of carbon deposits during the thermal stressing of JP-8 fuel in a flow reactor generating both filamentous, crystalline, amorphous, and metal carbide deposits. The sulfur compounds in the jet fuel led to the formation of metal sulfides that cause surface corrosion and expand the surface area available for carbon deposition. The binary alloys of Fe and Ni further increased both carbon and sulfur deposition depending on the Fe content. The Cr addition to Ni inhibited the catalytic activity of Ni significantly compared to the Ni and Fe alloys.