Accession Number : ADA117155

Title :   Fracture & Fatigue Characteristics in Titanium Alloys.

Descriptive Note : Final rept. 1 Jul 79-30 Sep 81,

Corporate Author : ROCKWELL INTERNATIONAL THOUSAND OAKS CA SCIENCE CENTER

Personal Author(s) : Rhodes,C G ; Mitchell,M R ; Chesnutt,J C

PDF Url : ADA117155

Report Date : Jun 1982

Pagination or Media Count : 125

Abstract : The influence of sub-transus solution treatment on room temperature fracture toughness of Ti-6Al-4V (6-4) and Ti-4.5Al-5Mo-1.5Cr (CORONA-5) has been studied as a function of elemental partitioning and volume fraction of alpha and beta phases. Scanning/transmission electron microscopy was used to analyze quantitatively the microstructural components of the two alloys. It was found that, for as-solution treated condition, fracture toughness of 6-4 increased as volume fraction of primary alpha, aluminum content of primary alpha, aluminum content of beta phase, or vanadium content of beta phase decreased. Similarly, for as-solution treated CORONA-5, increases in volume fraction of primary alpha, aluminum and molybdenum contents of primary alpha, or chromium content of beta phase led to a decrease in toughness. In the case of solution-treated and aged 6-4, the analysis indicated that toughness was improved by increasing the vanadium content of the beta phase, increasing the size of secondary alpha plates, reducing the aluminum content of primary alpha, or by reducing the volume fraction of retained beta. Aging CORONA-5 after solution treatment resulted in a very fine secondary alpha structure within transformed beta regions.

Descriptors :   *TITANIUM ALLOYS, *FRACTURE(MECHANICS), *TOUGHNESS, *FATIGUE(MECHANICS), CRACK PROPAGATION, TENSILE PROPERTIES, MICROSTRUCTURE, SURFACE PROPERTIES, HYDROGEN, PHASE TRANSFORMATIONS, CONCENTRATION(COMPOSITION), SOLUTION HEAT TREATMENT, ISOSTATIC PRESSING, HOT PRESSING, TEMPERATURE, COOLING, AGING(MATERIALS), POWDER METALS, ELECTRON MICROSCOPY

Subject Categories : Properties of Metals and Alloys
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE