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31. Methods of selective characterization during development of carbon and graphite materials for re-entry applications
714
CARBON
31. Methods of selective characterization during development of carbon aud graphite materials for re-entry applications E. R. Stover ( Aero~c~~s and M~~ ~b~a~, R~-Ens Systems, General Electrk Gom~an~, Philadelphia, Pen~yZuan~a). A review of methods available for selective identification and quantitative measurement of material characteristics pertinent to material optimization for re-entry applications is presented. Emphasis is placed on the basis for selecting techniques which serve to guide, at minimum cost, the adjustment of raw material and processing parameters based on product character and properties in order to improve thermostructural performance and reduce surface recession. 32. Characterization of a carbon composite, pyre-carb 406, for thermal stress performance predictiOllS
E. R. Stover and W. Connell (Aeromechanics and Materials Laboratory, Re-Entry Systems, General El&& Company, Philadelphia, Pennsylvania) and R. N. Woldstad (Isotope Power Systems Operation, Space Systems, General Electric Company, Philadelphia, Pennsylvania). A case history is presented of selective material characterization of critical structural parameters, mechanical properties, fracture characteristics and thermal expansion. Selection of tests and techniques from initial specification and determination of properties on plates to qualification of flight hardware are described. 33. The incorporation of glassy carbon in metals T. Ryan, K. Kawamura and G. Jenkins (Department of Metallurgy, University of Wales, Swansea, U.K.). It is shown that glassy carbon may be dispersed in aluminium by up to 4Ovol.% to form hard, light composites in which the aluminium/carbon bond is intimate and strong. No dissolution of the carbon in the aluminium is observed, The properties and potential uses of these composites is assessed. Results on copper and nickel composities are also reported. 34. The development of high strength carbon-metal composites T. Ishikawa, T. Hiratsuka and H. Yamazoe (N$@n Carbon Company, Tokyo,Ja@un). We have developed the manufacturing process of ultra high strength carbon-metal composite and its non-destructive inspection using seal or vane for severe repeating vibrated and high speed revoluted machine, which condition is not endurable for traditional carbon material. 35. The use of graphite in laser discharge structures M. Seiden (Research Dizkion, Raytheon Company, Walthum, Massachusetts). During the past two years several types of graphite have been used as bore material in ionized gas lazers. The use of these materials has improved the lifetime and reliability of argon and krypton lasers to a point where the majority of manufacturers have chosen graphite over other materials for use in their lasers. At our laboratory an experimental argon-krypton laser with a segmented, pyrolytic-graphite bore has been in operation for the past two years, and it is still functioning as a major research tool. The advantages as well as the problems caused by the use of graphite in laser structures will be discussed. 36. Joining graphite to graphite with transition metal foils D. J. Sandstrom (Los Alamos Scientzjk Laboratory, University of California, Los Alamos, New Metio). A study has been undertaken to determine the ‘relationship of metallic-foil joining and joining parameters to the strength of joints made in a high quality extruded nuclear graphite. Representative metals from Groups IVA, VA, and VIA were used for joining experiments. The parameters used for joining yielded either fully diffused joints, which were not temperature limited with respect to service conditions, or a continuous-carbide-interface joint which was tem~rature-limited. Properties in graphite joints were measured over the temperature range from room temperature to 2800°C. The strength of thejoints was related to the structure developed in joining by metallography, electron microscopy and X-ray diffraction studies. Mechanisms for joint formation are proposed and comparative strength relationships to heat of formation are inferred. 37. Structure, properties and applications of highly oriented graphite A. W. Moore, S. L. Strong and N. F. Graves (U&n Garb& Co~~a~on, Carbon Products Dixon, Parmu Technical Center, Cleveland, Ohio). A review is given of the structure and properties of highly oriented compression-annealed pyrolytic graphite. Novel applications of highly oriented graphite are
CARBON
31. Methods of selective characterization during development of carbon aud graphite materials for re-entry applications E. R. Stover ( Aero~c~~s and M~~ ~b~a~, R~-Ens Systems, General Electrk Gom~an~, Philadelphia, Pen~yZuan~a). A review of methods available for selective identification and quantitative measurement of material characteristics pertinent to material optimization for re-entry applications is presented. Emphasis is placed on the basis for selecting techniques which serve to guide, at minimum cost, the adjustment of raw material and processing parameters based on product character and properties in order to improve thermostructural performance and reduce surface recession. 32. Characterization of a carbon composite, pyre-carb 406, for thermal stress performance predictiOllS
E. R. Stover and W. Connell (Aeromechanics and Materials Laboratory, Re-Entry Systems, General El&& Company, Philadelphia, Pennsylvania) and R. N. Woldstad (Isotope Power Systems Operation, Space Systems, General Electric Company, Philadelphia, Pennsylvania). A case history is presented of selective material characterization of critical structural parameters, mechanical properties, fracture characteristics and thermal expansion. Selection of tests and techniques from initial specification and determination of properties on plates to qualification of flight hardware are described. 33. The incorporation of glassy carbon in metals T. Ryan, K. Kawamura and G. Jenkins (Department of Metallurgy, University of Wales, Swansea, U.K.). It is shown that glassy carbon may be dispersed in aluminium by up to 4Ovol.% to form hard, light composites in which the aluminium/carbon bond is intimate and strong. No dissolution of the carbon in the aluminium is observed, The properties and potential uses of these composites is assessed. Results on copper and nickel composities are also reported. 34. The development of high strength carbon-metal composites T. Ishikawa, T. Hiratsuka and H. Yamazoe (N$@n Carbon Company, Tokyo,Ja@un). We have developed the manufacturing process of ultra high strength carbon-metal composite and its non-destructive inspection using seal or vane for severe repeating vibrated and high speed revoluted machine, which condition is not endurable for traditional carbon material. 35. The use of graphite in laser discharge structures M. Seiden (Research Dizkion, Raytheon Company, Walthum, Massachusetts). During the past two years several types of graphite have been used as bore material in ionized gas lazers. The use of these materials has improved the lifetime and reliability of argon and krypton lasers to a point where the majority of manufacturers have chosen graphite over other materials for use in their lasers. At our laboratory an experimental argon-krypton laser with a segmented, pyrolytic-graphite bore has been in operation for the past two years, and it is still functioning as a major research tool. The advantages as well as the problems caused by the use of graphite in laser structures will be discussed. 36. Joining graphite to graphite with transition metal foils D. J. Sandstrom (Los Alamos Scientzjk Laboratory, University of California, Los Alamos, New Metio). A study has been undertaken to determine the ‘relationship of metallic-foil joining and joining parameters to the strength of joints made in a high quality extruded nuclear graphite. Representative metals from Groups IVA, VA, and VIA were used for joining experiments. The parameters used for joining yielded either fully diffused joints, which were not temperature limited with respect to service conditions, or a continuous-carbide-interface joint which was tem~rature-limited. Properties in graphite joints were measured over the temperature range from room temperature to 2800°C. The strength of thejoints was related to the structure developed in joining by metallography, electron microscopy and X-ray diffraction studies. Mechanisms for joint formation are proposed and comparative strength relationships to heat of formation are inferred. 37. Structure, properties and applications of highly oriented graphite A. W. Moore, S. L. Strong and N. F. Graves (U&n Garb& Co~~a~on, Carbon Products Dixon, Parmu Technical Center, Cleveland, Ohio). A review is given of the structure and properties of highly oriented compression-annealed pyrolytic graphite. Novel applications of highly oriented graphite are