Accession Number : AD0700653

Title :   METALLURGICAL STABILITY OF THE TITANIUM ALLOYS 8Al-1V-1Mo, 6Al-6V-2Sn, 4Al-3Mo-1V, AND 6Al-4V,

Corporate Author : BOEING CO RENTON WASH COMMERCIAL AIRPLANE DIV

Personal Author(s) : Finden,Pete T.

Report Date : 15 DEC 1969

Pagination or Media Count : 67

Abstract : Four commercial alloys - Ti 8Al-1Mo-1V, Ti 6Al-6V-2Sn, Ti 4Al-3Mo-1V, and Ti 6Al-4V - were evaluated to determine the effect of SST environmental conditions on mechanical properties. Test data for materials subjected to stressed thermal exposures for times from 1000 hours to 30,000 hours are compared to as-heat treated properties for most of the common heat treatment conditions (solution treated and overaged, mill annealed and air cooled, and duplex annealed with air cooling) of these alloys. It was found that of the alloys examined, only Ti 6Al-4V is not detrimentally affected by the exposure conditions tested. The test results indicate that furnace cooling (at 80F/hour to 800F in this study) from either the annealing temperature or the aging - stabilization treatment imparts the required metallurgical stability for SST usage of the other three alloys - Ti 8Al-1Mo-1V, Ti 6Al-6V-2Sn, and Ti 4Al-3Mo-1V. Property changes resulting from exposure are satisfactorily explained by changes in microstructural features as determined using transmission electron microscopy and X-ray diffraction. (Author)

Descriptors :   (*SUPERSONIC AIRCRAFT, TITANIUM ALLOYS), (*TITANIUM ALLOYS, THERMAL STABILITY), AIRFRAMES, HEAT TREATMENT, ENVIRONMENTAL TESTS, AERODYNAMIC HEATING, AERODYNAMIC LOADING, MECHANICAL PROPERTIES, ALUMINUM ALLOYS, MOLYBDENUM ALLOYS, VANADIUM ALLOYS, TIN ALLOYS, STABILITY

Subject Categories : Transport Aircraft
      Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE