Accession Number : AD0824691

Title :   DEVELOPMENT OF IMPROVED BIAXIAL STRENGTH IN TITANIUM ALLOY ROCKET MOTOR CASES THROUGH TEXTURE HARDENING.

Descriptive Note : Phase rept. 1 Mar-10 Dec 67,

Corporate Author : LOCKHEED MISSILES AND SPACE CO INC PALO ALTO CA

Personal Author(s) : Fitzpatrick, J. M. ; Crossley, F. A. ; Hoffman, O. ; Tsui, E. Y. W. ; Lewis, R. E.

Report Date : DEC 1967

Pagination or Media Count : 150

Abstract : A strength-to-density ratio of 1,500,000 in. was designated as a goal for textured sheet under 1:2 biaxial stress conditions. The effort was toward the determination of suitable rolling and heat-treating procedures for development of favorable textures in one or both of two alloys: Ti-6Al-4V and Ti-7Al-2.5 Mo. The work comprised the following aspects: rolling and heat treating trials; identification of textures through measurements of associated anisotropic mechanical properties; determination of fracture toughness indices; texture characterization through pole figure analyses and optical metallography; and analytical study to develop methods of predicting the mechanical behavior of pressure vessels fabricated from textured alloys. The lateral strain ratio R has been used for the purpose of assessing biaxial strength by calculations based on the anisotropic plasticity theory of R. Hill. The highest calculated biaxial yield strength was found for Ti-6Al-4V sheet that had been multidirectionally rolled. The calculated 1:2 biaxial yield strength-to-density of this material is 1,400,000 in., an improvement of approximately 16% over previously reported experimental values for this material. (Author)

Descriptors :   *TITANIUM ALLOYS), (*ROCKET ENGINE CASES, ROCKET ENGINES, ROLLING(METALLURGY), HEAT TREATMENT, FRACTURE(MECHANICS), TOUGHNESS, ALUMINUM ALLOYS, VANADIUM ALLOYS, MOLYBDENUM ALLOYS, TENSILE PROPERTIES, ANISOTROPY, MICROSTRUCTURE, MECHANICAL PROPERTIES.

Subject Categories : Properties of Metals and Alloys
      Rocket Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE