ICMCTF1999 Session AP: AP Posters

Tuesday, April 13, 1999 5:00 PM in Room Atlas Foyer

Tuesday Afternoon

Time Period TuP Sessions | Topic A Sessions | Time Periods | Topics | ICMCTF1999 Schedule

AP-1 On Oxidation Behaviors of Diamondlike Carbon Films
D.Y. Wang, C.L. Chang (National Chung Hsing University, Taiwan, ROC); W.Y. Ho (Surftech Corp., Taiwan, ROC)
In the study, diamondlike carbon films¡]DLC¡^were synthesized by unbalanced magnetron sputtering, a combined PVD and PECVD process to produce a microstructure consisting of a Ti interlayer, a graded transition layer, and a DLC layer. Influences of reactive gas composition and biasing potential on the oxidation resistance of DLC films were investigated with thermogravimetric (TG) and thermal differential (TD) analyses. The phase identification and microstructure examination were conducted with XRD, Raman, and SEM/EDS. Results indicated that DLC films disintegrated at temperatures above 350¢J, showing a typical graphitic transformation and oxidation behaviors. The onset temperature depends on the structure density and the ratio of sp3 versus sp2 bonds of DLC films. Thus, deposition parameters and structure design provided an effective means to enhance the oxidation performance of DLC films.
AP-2 Synthesis of ß - Silicon Carbide Coatings on Carbon-Carbon Composite Materials from Silicon Nitride Powders
E.E. Koshchug, N.N. Repnikov (Institute of Physical Chemistry, RAS, Russia); A.N. Timofeev (NPO, Russia)
Charge of Si3N4 fine dispersed powder was used for high temperature synthesis of ß-SiC coating on carbon-carbon materials with density of 1.3-1.9 kg/m3. The kinetic of the formation process of ß-SiC coating at temperatures up to 2200 K in vacuum and Ar atmosphere were investigated. The coating-substrate adhesive strength, long-time oxidizing resistance in air atmosphere and the possibilities of the method to manufacture functionally-graded coatings for protection from oxidation, radiation and abrasive wear are discussed.
AP-3 FCCU Expander Corrosion/Erosion High Temperature Failure
G. Navas, L. Viloria (PDVSA, Intevep, S.A., Venezuela)
The fluid catalytic cracking unit (FCCU) of El Palito Refinery processes fifty-four thousand barrels per day. The unit is a UOP license with a catalyst regenerator that operates in a complete combustion mode. A power recovery system is used to recover waste energy from the flue gas stream. The combustion products pass through a power recovery turbine, or expander, before going to a waste heat boiler. The unit has a Dresser-Rand E-148 single stage expander, which delivers 14,168 Kw. (19,000 hp) shaft power. The inlet temperature of flue gas is 704°C (1300 °F) at a pressure of 266 Mpa (38 psig), whereas exhaust temperature is approximately 593 °C (1100 °F) at a pressure of 15.5 Mpa (2.2 psig). The mass flow rate through the expander is of the order of 3,400-3,738 m3/min (120,000-132,000 ft3/min).
AP-4 Chromizing and Aluminizing Bed Treatment by CVD in Fluidized Bed Reactor on Austenitic Stainless Steels
F.J. Pérez, M.P. Hierro, C. Gómez, F. Pedraza, M.C. Carpintero, E. Otero (Universidad Complutense de Madrid, Spain)
Austenitic stainless steels have a limitation in uses at high temperatures, due to their alloying composition and carbide precipitation. In order to increase the composition on the surface in Cr and Al, CVD processes performed in fluidized beds have been applied on AISI 304 stainless steel. The advantages of the CVD-FBR in deposition time and temperature of deposition allows to establish possible industrial applications. The order to analyze the corrosion enhance due to the corrosion process. Oxidation kinetics have been obtained under isothermal conditions up to 200 hours of test. Mechanism of oxidation of coated materials have been established.
Time Period TuP Sessions | Topic A Sessions | Time Periods | Topics | ICMCTF1999 Schedule