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037 a| N 84-17353b| NASA;

040 a| CODc| CODd| GPOd| MvI;

049 a| ERE$;

074 a| 0830-D (MF);

074 a| 0830-D (online);

086 0 a| NAS 1.15:83595;

100 1 a| MacKay, Rebecca A.=| ^A787489;

245 10 a| Factors which influence directional coarsening of Gamma prime during creep in nickel-base superalloy single crystals /c| Rebecca A. MacKay and Lynn J. Ebert.;

260 a| [Cleveland, Ohio] :b| National Aeronautics and Space Administration, Lewis Research Center,c| [1984];

300 a| 10 p. :b| ill. ;c| 28 cm.;

336 a| textb| txt2| rdacontent;

337 a| microformb| h2| rdamedia;

338 a| microficheb| he2| rdacarrier;

490 1 a| NASA TM ;v| 83595;

500 a| Prepared for the fifth International Symposium on Superalloys sponsored by the American Institute of Mining, Metallurgical and Petroleum Engineers, Seven Springs, Pennsylvania, October 7-11, 1984.;

500 a| GPO Cataloging Record Distribution Program (CRDP).;

504 a| Includes bibliographical references (p. 10).;

520 a| "Changes in the morphology of the gamma prime precipitate were examined as a function of time during creep at 982 C in 001 oriented single crystals of a Ni-Al-Mo-Ta superalloy. In this alloy, which has a large negative misfit of -0.80 pct., the gamma prime particles link together during creep to form platelets, or rafts, which are aligned with their broad faces perpendicular to the applied tensile axis. The effects of initial microstructure and alloy composition of raft development and creep properties were investigated. Directional coarsening of gamma prime begins during primary creep and continues well after the onset of second state creep. The thickness of the rafts remains constant up through the onset of tertiary creep a clear indication of the stability of the finely-spaced gamma gamma prime lamellar structure. The thickness of the rafts which formed was equal to the initial gamma prime size which was present prior to testing. The single crystals with the finest gamma prime size exhibited the longest creep lives, because the resultant rafted structure had a larger number of gamma gamma prime interfaces per unit volume of material. Reducing the Mo content by only 0.73 wt. pct. increased the creep life by a factor of three, because the precipitation of a third phase was eliminated."--NASA Technical Reports Server web site;

530 a| Also available via Intertnet from the NTRS web site. Address as of 08/27/08: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840009285%5F1984009285.pdf ; current access is available via PURL.;

536 a| Grantc| NSG-3246;

650 0 a| Heat resistant alloysx| Creep.=| ^A257282;

650 0 a| Heat resistant alloysv| Congresses.=| ^A787490;

650 7 a| Creep properties.2| nasat;

650 7 a| Heat resistant alloys.2| nasat;

650 7 a| Nickel alloys.2| nasat;

650 7 a| Single crystals.2| nasat;

700 1 a| Ebert, Lynn J.=| ^A785605;

711 2 a| International Symposium on Superalloysn| (5th :d| 1984 :c| Champion, Pa.)?| UNAUTHORIZED;

710 2 a| American Institute of Mining, Metallurgical, and Petroleum Engineers.=| ^A25833;

710 2 a| Lewis Research Center.=| ^A367825;

830 0 a| NASA technical memorandumv| 83595.=| ^A467613;

856 41 u| https://purl.fdlp.gov/GPO/LPS100936;

949 a| NAS 1.15:83595w| sudoch| joyner32;

596 a| 1;

998 a| 1430716;

999 a| NAS 1.15:83595w| SUDOCc| 1i| MQ2684928l| JDOMIm| JOYNERr| Ys| Yt| JDOFMIu| 10/13/2008x| MICROFORMz| JFEDDOCSo| .STAFF. 0;

Factors which influence directional coarsening of Gamma prime during creep in nickel-base superalloy single crystals / Rebecca A. MacKay and Lynn J. Ebert.

Author/creator	MacKay, Rebecca A.
Format	Microform
Publication Info	[Cleveland, Ohio] : National Aeronautics and Space Administration, Lewis Research Center, [1984]
Description	10 p. : ill. ; 28 cm.
Supplemental Content	https://purl.fdlp.gov/GPO/LPS100936
Subjects	Heat resistant alloys--Creep. Heat resistant alloys--Congresses.

Other author/creator	Ebert, Lynn J.
Other author/creator	American Institute of Mining, Metallurgical, and Petroleum Engineers.
Other author/creator	Lewis Research Center.
Other author/creator	International Symposium on Superalloys 1984 : Champion, Pa.) (5th :
Series	NASA TM ; 83595 NASA technical memorandum 83595. ^A467613
Abstract	"Changes in the morphology of the gamma prime precipitate were examined as a function of time during creep at 982 C in 001 oriented single crystals of a Ni-Al-Mo-Ta superalloy. In this alloy, which has a large negative misfit of -0.80 pct., the gamma prime particles link together during creep to form platelets, or rafts, which are aligned with their broad faces perpendicular to the applied tensile axis. The effects of initial microstructure and alloy composition of raft development and creep properties were investigated. Directional coarsening of gamma prime begins during primary creep and continues well after the onset of second state creep. The thickness of the rafts remains constant up through the onset of tertiary creep a clear indication of the stability of the finely-spaced gamma gamma prime lamellar structure. The thickness of the rafts which formed was equal to the initial gamma prime size which was present prior to testing. The single crystals with the finest gamma prime size exhibited the longest creep lives, because the resultant rafted structure had a larger number of gamma gamma prime interfaces per unit volume of material. Reducing the Mo content by only 0.73 wt. pct. increased the creep life by a factor of three, because the precipitation of a third phase was eliminated."--NASA Technical Reports Server web site
General note	Prepared for the fifth International Symposium on Superalloys sponsored by the American Institute of Mining, Metallurgical and Petroleum Engineers, Seven Springs, Pennsylvania, October 7-11, 1984.
General note	GPO Cataloging Record Distribution Program (CRDP).
Bibliography note	Includes bibliographical references (p. 10).
Other forms	Also available via Intertnet from the NTRS web site. Address as of 08/27/08: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840009285%5F1984009285.pdf ; current access is available via PURL.
Reproduction note	Microfiche. [Washington, D.C. : National Aeronautics and Space Administration], 1984. 1 microfiche : negative.
Funding information	Grant NSG-3246
GPO item number	0830-D (MF)
GPO item number	0830-D (online)
Govt. docs number	NAS 1.15:83595
Stock number	N 84-17353 NASA

Factors which influence directional coarsening of Gamma prime during creep in nickel-base superalloy single crystals / Rebecca A. MacKay and Lynn J. Ebert.

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