Effects of tantalum on the structure/properties of polycrystalline nickel-base superalloy Mar-M 247

Conference · · TMS (The Metallurgical Society) Paper Selection; (USA)

OSTI ID:5310143

Janowski, G M; Heckel, R W; Pletka, B J ^[1]

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1. Michigan Technological Univ., Houghton (USA)

The microstructure/high temperature mechanical properties of equiaxed and directionally solidified (D.S.) alloys based on the Mar-M 247 composition with tantalum variations have been studied. The as-cast, heat treated, and post-creep tested microstructures were characterized. Cubodial {gamma}{prime} is present in the as-cast structure and exhibits a spheroidal morphology after heat treatment. MC carbides are present in the as-cast structure and additional M{sub 6}C carbides form during heat treatment. Ta was observed to replace Hf in the MC carbides; the displayed Hf entered the {gamma} and {gamma}{prime} phases. Rafting of {gamma}{prime} was observed after creep testing at 1800 F but not at 1600 and 1400 F in the D.S. alloys. Tantalum additions enhanced both the hot tensile and creep properties of the alloys. The effect of tantalum variations and comparison of mechanical properties to single crystal Mar-M 247 are discussed.

• OSTI ID: 5310143
• Report Number(s): CONF-840909--
• Conference Information: Journal Name: TMS (The Metallurgical Society) Paper Selection; (USA) Journal Volume: 56
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
ALLOYS
CARBIDES
CARBON COMPOUNDS
COMPARATIVE EVALUATIONS
CREEP
CRYSTAL STRUCTURE
CRYSTALS
ELEMENTS
HAFNIUM
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HEAT TREATMENTS
MATERIALS
MECHANICAL PROPERTIES
METALLURGICAL EFFECTS
METALS
MICROSTRUCTURE
MORPHOLOGY
NICKEL ALLOYS
NICKEL BASE ALLOYS
POLYCRYSTALS
TANTALUM
TANTALUM ADDITIONS
TANTALUM ALLOYS
TENSILE PROPERTIES
TRANSITION ELEMENTS