Accession Number : ADD012888

Title :   Method for Refining Microstructures of Prealloyed Titanium Powder Compacted Articles.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : Levin,Lev ; Vogt,Russell G ; Eylon,Daniel ; Froes,Francis H

Report Date : 07 Apr 1987

Pagination or Media Count : 6

Abstract : In accordance with the present invention there is provided a process for improving the microstructure of a titanium article made by powder metallurgy which comprises, in combination, the steps of: beta-solution heat treating the article for a relatively brief time; quenching the article; hydrogenating the article; and dehydrogenating the article. The method of the present invention comprises beta solution treatment of an article produced by powder metallurgy, followed by hydrogenation/dehydrogenation of the article. The beta-solution treatment is accomplished by heating the article, in an inert atmosphere of argon, helium, nitrogen, or the like, to approximately the beta-transus temperature of the alloy, i.e., from about 5% below to about 10% above the beta-transus temperature (in C.), followed by rapid cooling. In a presently preferred embodiment, the beta-solution heat treatment is conducted by heating the article to a temperature in the approximate range of 0 to 5% above the beta-transus of the alloy, followed by rapid cooling. The period of time over which the article is held at or near the beta-transus temperature can vary from about 10 minutes to about 240 minutes, depending on the cross-section of the article, with thinner articles requiring a shorter holding time. The article can be quenched, i.e. cooled, in a flowing stream of cooled gas, such as air, or in water or oil.

Descriptors :   *PATENTS, *SOLUTION HEAT TREATMENT, *DEHYDROGENATION, *HYDROGENATION, *MICROSTRUCTURE, *REFINING, *TITANIUM ALLOYS, CROSS SECTIONS, TIME, QUENCHING, COOLING, GASES, HELIUM, ARGON, ATMOSPHERES, RARE GASES, NITROGEN, POWDER METALLURGY, HIGH RATE, ISOSTATIC PRESSING, HOT WORKING, COMPACTING, MECHANICAL WORKING, STRENGTH(MECHANICS), CYCLIC TESTS, ALUMINUM ALLOYS, VANADIUM ALLOYS, TIN ALLOYS, MOLYBDENUM ALLOYS, ZIRCONIUM ALLOYS

Subject Categories : Properties of Metals and Alloys
      Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE