Accession Number : AD0652829

Title :   RESEARCH AND DEVELOPMENT OF PHYSICAL METALLURGY OF TITANIUM.

Descriptive Note : Final rept., 1 Aug 65-30 Jun 66,

Corporate Author : IIT RESEARCH INST CHICAGO ILL

Personal Author(s) : Crossley,Frank A.

Report Date : APR 1967

Pagination or Media Count : 205

Abstract : The objectives of the program were to determine the following: (1) the effects of the ternary alpha-soluble additions oxygen, tin, and zirconium, and the beta-stabilizing additions columbium, molybdenum, and vanadium on the extent of Ti-Al primary alpha; (2) the effects of these ternary additions on the kinetics of precipitation of Ti3Al; and (3) the relationships of the foregoing to mechanical properties. The most significant findings of the three-part study were as follows: Oxygen, Zr, Cb, Mo, and V decreased the extent of primary alpha; on the other hand, Sn increased the extent of primary alpha. Extrapolation of data for higher temperatures suggested that below 700C, V may increase the extent of primary alpha in terms of total substitutional solutes. The kinetics study showed that displacement in time between the Ti3Al precipitation reaction at grain boundaries and within grains is significant in Ti-Al binary and Ti-Al-Sn ternary alloys. Additions of Zr, Cb, Mo, and V retarded the precipitation reaction and appeared to inhibit or suppress it at grain boundaries. The nose of the TTT curves for the precipitation reaction was about 650C. Impact resistance and tensile ductility went through a minimum upon aging at 650C and were completely recovered in 500 hr for the Ti-7.1 wt pct Al alloy.

Descriptors :   (*TITANIUM ALLOYS, *METALLURGY), (*ALUMINUM ALLOYS, *ADDITIVES), CHEMICAL ANALYSIS, CHEMICAL PRECIPITATION, GRAIN BOUNDARIES, IMPACT SHOCK, SHOCK RESISTANCE, PHASE STUDIES, TOUGHNESS, STABILIZATION, SOLUBILITY, MECHANICAL PROPERTIES, MATHEMATICAL PREDICTION, TENSILE PROPERTIES, DUCTILITY, TIN ALLOYS, CHEMICAL EQUILIBRIUM

Subject Categories : Physical Chemistry
      Properties of Metals and Alloys
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE