Laser-clad Ni sub 70 Al sub 20 Cr sub 7 Hf sub 3 alloys with extended solid solution of Hf; Part I. Microstructure evolution

Journal Article · Wed Nov 01 00:00:00 EST 1989 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (USA)

DOI:https://doi.org/10.1007/BF02666662· OSTI ID:6986559

Sircar, S; Ribaudo, C; Mazumder, J ^[1]

---

1. Laser Aided Materials Processing Lab., Dept. of Mechanical and Industrial Engineering, Univ. of Illinois at Urbana-Champaign, Urbana, IL (US)

Coatings for superalloys for extended service in atmospheres at high temperature are of great interest at present. The addition of reactive elements (RE's) such as Hf to these coatings has a pronounced effect on their high-temperature oxidation resistance. A laser cladding technique was used to produce Ni-Al-Cr-Hf alloys with an extended solid solution of Hf in a near-stoichiometric Ni{sub 3}Al matrix. A 10 kW CO{sub 2} laser with mixed powder feed was used for the cladding process. Scanning electron microscope (SEM), transmission electron microscope (TEM), and scanning transmission electron microscope (STEM) were employed for studies of microstructural evolution of alloys produced during the processes. Microstructural studies reveal the formation of dendrites with a solid solubility of about 11 to 14 wt pct Hf and also a eutectic structure. Convergent-beam techniques and x-ray spectroscopy have been applied to characterize the phases formed during cladding.

• OSTI ID: 6986559
• Journal Information: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (USA), Vol. 20A:11; ISSN 0360-2133
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM ALLOYS
MICROSTRUCTURE
CHROMIUM ALLOYS
HAFNIUM ALLOYS
NICKEL BASE ALLOYS
CLADDING
COATINGS
CORROSION RESISTANCE
HAFNIUM ADDITIONS
HIGH TEMPERATURE
SCANNING ELECTRON MICROSCOPY
SOLID SOLUTIONS
STOICHIOMETRY
TRANSMISSION ELECTRON MICROSCOPY
X-RAY SPECTRA
ALLOYS
CRYSTAL STRUCTURE
DEPOSITION
DISPERSIONS
ELECTRON MICROSCOPY
MICROSCOPY
MIXTURES
NICKEL ALLOYS
SOLUTIONS
SPECTRA
SURFACE COATING
360102* - Metals & Alloys- Structure & Phase Studies
400101 - Activation
Nuclear Reaction
Radiometric & Radiochemical Procedures
656002 - Condensed Matter Physics- General Techniques in Condensed Matter- (1987-)