Influences of directionally solidified techniques and hafnium content on a nickel base high temperature alloy

Technical Report · Thu Mar 01 04:00:00 EST 1984

OSTI ID:6177074

Luobao, W; Rongzhang, C; Yuping, W

Two directionally solidified techniques, the power decrease (P.D.) and high rate solidification (H.R.S.) methods, are used to study the influences of the different Hf contents on the structures and properties of a nickel base high temperature alloy. When entering the alloy the Hf is mainly segregated in the interdentritic regions and gamma/gamma prime eutectic phases. After the alloy is added, there are noticeable changes in the microstructure. The amount of gamma/gamma prime eutectic phase noticeably increases. Its morphology also undergoes noticeable changes. The conditions of grain boundaries and interdentritic regions are improved. Several new types of Hf-rich microfacies also appeared. At 760 C, the endurance properties (especially the transverse properties) of the alloy noticeably rise with the increase of the Hf content. However, at 1040 C, the endurance life decreases with the increase of the Hf content. When the H.R.S. technique is used, the medium and high temperature performances of the alloy are both noticeably superior to the P.D. technique.

• Research Organization: National Aeronautics and Space Administration, Greenbelt, MD (USA). Goddard Space Flight Center
• OSTI ID: 6177074
• Report Number(s): N-84-30064
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102 -- Metals & Alloys-- Structure & Phase Studies
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
CRYSTAL STRUCTURE
HAFNIUM ADDITIONS
HAFNIUM ALLOYS
MECHANICAL PROPERTIES
MICROSTRUCTURE
MORPHOLOGY
NICKEL ALLOYS
NICKEL BASE ALLOYS
PHASE TRANSFORMATIONS