Advanced investment cast processing for gamma titanium aluminide alloys

Book · Sun Dec 31 04:00:00 EST 1995

OSTI ID:225113

Larsen, D; Govern, C ^[1]

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1. Howmet Corp., Whitehall, MI (United States)

Investment casting of gamma titanium aluminide alloys has become the near-term process of choice for component manufacture. This is largely due to its near-net shape processing capabilities which allow cast gamma components to be manufactured at a lower cost when compared to wrought or powder methods. Many papers have been published discussing the effect of heat treatment on the microstructure of HIP processed samples. However, the relationship between casting parameters and resultant microstructures has not been widely discussed. An L9 DOE casting experiment was performed to examine mold preheat, furnace atmosphere, shell type and gating design parameters. It was determined that mold preheat had a very significant effect on as-cast and as-HIP processed microstructures. Mold preheats of 70 F and 750 F produced HIP Processed microstructures containing 80 to >90% equiaxed gamma grains and 2,100 F mold preheats produced structures containing 10--30% equiaxed gamma grains. The results of this experiment will be presented, including optical microstructures and microprobe analysis.

• OSTI ID: 225113
• Report Number(s): CONF-950201--; ISBN 0-87339-304-X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
CASTING
CHEMICAL COMPOSITION
CHROMIUM ALLOYS
DENDRITES
ELECTRON MICROPROBE ANALYSIS
EXPERIMENTAL DATA
HOT PRESSING
INTERMETALLIC COMPOUNDS
LAMELLAE
METALLOGRAPHY
MICROSTRUCTURE
NIOBIUM ALLOYS
OPTICAL MICROSCOPY
TITANIUM ALLOYS