Accession Number : ADA193222

Title :   Effect of Microstructure on the Fatigue Crack Propagation Behavior of Ni-Base Superalloys.

Descriptive Note : Technical rept. 1 May 84-30 Sep 87,

Corporate Author : GEORGIA INST OF TECH ATLANTA SCHOOL OF MATERIALS ENGINEERING

Personal Author(s) : Antolovich, Stephen D

PDF Url : ADA193222

Report Date : Dec 1987

Pagination or Media Count : 100

Abstract : The objective of this study is to determine the effect of microstructural properties on the fatigue crack propagation (FCP) response of nickel-base superalloys. This report describes the results of four experimental alloys containing various amounts of Al, Ti, Cr, and Mo. Chemistry, precipitate size, and grain size were varied to produce systematically controlled microstructures. The four alloys were characterized for chemical composition, microstructure, tensile properties, low cycle fatigue (LCF), and FCP resistance. The FCP tests were performed under constant load (increasing K) conditions in air at a stress ratio (R) of 0.1 and 0.8. Closure loads were measured with a clip gage, back-face strain gage, and a laser extensometer. Keywords: Fatigue crack propagation, Ni-base superalloys, Microstructure, Closure, Mismatch, Anti-phase boundary, Aluminum, Titanium, Chromium, Molybdenum.

Descriptors :   *CRACK PROPAGATION, *FATIGUE(MECHANICS), *NICKEL ALLOYS, *SUPERALLOYS, *TENSILE PROPERTIES, CHEMICAL COMPOSITION, CONSTANTS, CONTROL, CRACKING(FRACTURING), CYCLES, EXTENSOMETERS, FATIGUE, GRAIN SIZE, LASERS, LOADS(FORCES), MICROSTRUCTURE, PRECIPITATES, RATIOS, RESPONSE, SIZES(DIMENSIONS), STRAIN GAGES, STRESSES, ALUMINUM ALLOYS, CHROMIUM ALLOYS, MOLYBDENUM ALLOYS, TITANIUM ALLOYS

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE