Accession Number : ADB059014

Title :   Research to Conduct an Exploratory Experimental and Analytical Investigation of Alloys.

Descriptive Note : Interim technical rept. May 77-Dec 78,

Corporate Author : PRATT AND WHITNEY AIRCRAFT GROUP WEST PALM BEACH FL GOVERNMENT PRODUCTS DIV

Personal Author(s) : Blackburn,M. J. ; Smith,M. P.

Report Date : JUN 1981

Pagination or Media Count : 59

Abstract : Materials based on the intermetallic phases Ti3Al (alpha 2) and TiAl (gamma) exhibit several attractive features that make them candidates for gas turbine engine applications. Low density, good oxidation resistance and high temperature strength are such characteristics and could result in substitution for the nickel alloys currently used for components that operate at intermediate temperatures. The overall objectives of this portion of the program are to identify Ti3Al alloys with properties compatible with gas turbine applications and to develop preliminary processing and finishing techniques that are needed to make prototype hardware. The Ti-Al-Nb system has been shown to be the best system for alloy development. In the present study, higher aluminum contents, at a constant niobium level, have been shown to improve stress-rupture properties at the expense of ductility at low and intermediate temperatures. Additions of zirconium, tin, hafnium or carbon to a Ti-Al-Nb base do not produce improved mechanical properties. Substitution of vanadium for some of the niobium in Ti-25Al-11Nb appears useful in reducing cost and density of the alloys. Lower oxygen content was shown to be one of the most effective means to improve room temperature ductility.

Descriptors :   *TITANIUM ALLOYS, *ALUMINIDES, *GAS TURBINES, ALUMINUM ALLOYS, NIOBIUM ALLOYS, PHASE STUDIES, INTERMETALLIC COMPOUNDS, PHYSICAL PROPERTIES, MECHANICAL PROPERTIES, DUCTILITY, STRESSES, RUPTURE, MANUFACTURING, CASTING, NICKEL ALLOYS, SUBSTITUTES

Subject Categories : Properties of Metals and Alloys
      Fabrication Metallurgy
      Jet and Gas Turbine Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE