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Title: Innovative processing to produce advanced intermetallic materials. Phase 1 final report

The program demonstrates the technical feasibility of synthesizing submicron titanium aluminide in a thermal rf plasma. Micron and submicron spherical titanium aluminide particles are produced in argon, hydrogen, and argon/hydrogen plasmas from the reaction of TiCl4(g), and Al(g). The ratio of Ti and Al is varied to produce the compounds Ti3Al, TiAl, and TiAl3. Microalloying with boron and macroalloying with niobium is demonstrated. Ti3Al whiskers can be produced, as well as other intermetallics of niobium aluminide, nickel aluminide, and molybdenum disilicide in the plasma synthesis process. Since submicron particles are produced, they have a high surface area and are sensitive to oxidation if not treated with a fugitive protective coating or utilized in a nonoxidizing atmosphere. Ti3Al particles are consolidated and utilized as a matrix for TiC and AlN composites. The submicron AlTi3 has significantly higher strength at room temperature than reported for commercial Ti3Al-11Nb alloy and useable strength is maintained up to 1000 C. The elongation is about the same as for commercial material because of possible oxide contamination in powder handling. However, dimpling and nacking is evident in the fracture surface, which suggests true room temperature ductility. Titanium aluminides have the potential to replace superalloys and become themore » dominant material for aerospace engines, air frames and skins for hypersonic vehicles.« less
Authors:
Publication Date:
OSTI Identifier:
6896122
Report Number(s):
PB-93-158038/XAB
CNN: NSF-ISI88-60240
Resource Type:
Technical Report
Research Org:
Materials and Electrochemical Research Corp., Tucson, AZ (United States)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALUMINIUM ALLOYS; FABRICATION; INTERMETALLIC COMPOUNDS; MECHANICAL PROPERTIES; PROCESSING; TITANIUM ALLOYS; AEROSPACE INDUSTRY; ARGON; BORON; DUCTILITY; FEASIBILITY STUDIES; HASTELLOY X; HYDROGEN; MOLYBDENUM SILICIDES; NICKEL ALLOYS; NIOBIUM ALLOYS; PLASMA; TITANIUM CHLORIDES; WASPALOY; ALLOY-NI49CR22FE18MO9; ALLOY-NI58CR20CO14MO4TI3; ALLOYS; BORON ADDITIONS; BORON ALLOYS; CHLORIDES; CHLORINE COMPOUNDS; CHROMIUM ALLOYS; COBALT ALLOYS; CORROSION RESISTANT ALLOYS; ELEMENTS; FLUIDS; GASES; HALIDES; HALOGEN COMPOUNDS; HASTELLOYS; HEAT RESISTANT MATERIALS; HEAT RESISTING ALLOYS; INDUSTRY; IRON ALLOYS; MATERIALS; MOLYBDENUM ALLOYS; MOLYBDENUM COMPOUNDS; NICKEL BASE ALLOYS; NONMETALS; RARE GASES; REFRACTORY METAL COMPOUNDS; SEMIMETALS; SILICIDES; SILICON COMPOUNDS; T; TENSILE PROPERTIES; TITANIUM COMPOUNDS; TRANSITION ELEMENT COMPOUNDS; TUNGSTEN ADDITIONS; TUNGSTEN ALLOYS 360101* -- Metals & Alloys-- Preparation & Fabrication; 360103 -- Metals & Alloys-- Mechanical Properties