Accession Number : ADA297290

Title :   Fracture Toughness and Stress Corrosion Resistance of U-0.75 wt.% Ti,

Corporate Author : ARMY RESEARCH LAB WATERTOWN MA MATERIALS DIRECTORATE

Personal Author(s) : Zabielski, Chester V.

PDF Url : ADA297290

Report Date : APR 1995

Pagination or Media Count : 41

Abstract : As a consequence of the several failures of U-0.75 wt% Ti circumferentially grooved machined bars stressed at lower than normal ambient temperatures, an intensive fracture. toughness study of the U-0.75 wt% Ti material was carried out. The objective of the study was to determine the effect of heat treatment, microstructure, hardness, mechanical properties and test temperature on fracture toughness. Fracture toughness measurements in the temperature range of -73 deg C to +38 deg C were made for the alloy processed by (1) alpha extrusion, gamma vacuum solution treatment, directionally quenching in H2O, aging; (2) gamma rolling, gamma solution treatment in molten salt, plunge quenching in oil, aging; (3) solution treatment in vacuum for the material processed in (2), directionally quenching in H20 and re-aging. Two types of fracture toughness specimens were considered. Based on preliminary test data, a slow-bend precracked Charpy specimen was selected for final measurements. Data obtained was compared with the meager fracture toughness data for the alloy reported in the literature. Based on these data, a minimum fracture toughness requirement at -46 deg C as recommended. (MM)

Descriptors :   *TOUGHNESS, *FRACTURE(MECHANICS), *TITANIUM ALLOYS, TEST AND EVALUATION, TEMPERATURE, MECHANICAL PROPERTIES, EXPERIMENTAL DATA, MICROSTRUCTURE, AGING(MATERIALS), MACHINING, CRACKING(FRACTURING), VACUUM, EXTRUSION, MELTS, QUENCHING, HEAT TREATMENT, CORROSION RESISTANCE, STRESS CORROSION, SALTS, FAILURE(MECHANICS), HARDNESS, ROLLING(METALLURGY), SOLUTION HEAT TREATMENT.

Subject Categories : Properties of Metals and Alloys
      Fabrication Metallurgy

Distribution Statement : APPROVED FOR PUBLIC RELEASE