Glassy polymeric carbon is produced in the form of open- and closed-end tubes of uniform thickness up to 1 m long. Resol precursor is sprayed automatically to form a thin gelled coating on a rotating heated mandrel. The process is repeated to produce a sheath of thermoset phenolic resin of required thickness. This resin sheath is carbonized and heat treated between 1270 and 2770 K. Mass loss and contraction are noted. Structure is characterized by x-ray diffraction, which is also used to determine texture. Mechanical properties are measured using a specially designed hydraulic system to relate hoop strain to hoop stress. Hoop strength lies between 20 to 92 MPa, exhibiting brittle fracture variance. The scatter in the hoop strength data masked any heat treatment temperature effect. The measured electrical resistivity is 7xE-2 and 3 xE-2 for heat treatments of 1270 and 2770 K, respectively. Local induction heating has been used to demonstrate that the carbonized ware can endure sharp temperature gradients without fracturing. The hollow ware is used as a crucible for a new Bridgman crystal growth technique and for containment of hydrocarbon gases at high temperature.
NGG-40010 Dr. Alex Lehoczky, the NASA Space Grant Fellowship sponsor
NSF/MRCE NSF-HRB 9353548 Dr. Alton Williams, NSF/MRCE principle investigator
Nichols Research Corporation.
lamenating resin and suppling our research team with ample stock.
Send your comments to jon_fisher@netqm.nichols.com