Microstructure of laser-clad Ni-Cr-Al-Hf alloy on a gamma-strenghtened Ni-base superalloy

Technical Report · Mon Aug 01 04:00:00 EDT 1988

OSTI ID:6508177

Singh, J; Mazumder, J

Alloys and coatings for alloys for improved high-temperature service life under aggressive atmospheres are of great contemporary interest. There is a general consensus that the addition of materials such as Hf will provide many beneficial effects for such alloys. The laser cladding technique was used to produce Ni-Cr-Al-Hf alloys with extended solid solution of Hf. A 10-kW CO/sub 2/ laser with mixed power feed was used for laser cladding. Optical, scanning electron (SEM) and scanning transmission electron (STEM) microscopy were employed to characterize the microstructure of alloys produced during laser-cladding processes. Microstructural studies revealed grain refinement, considerable increase in solubility of Hf in the matrix, Hf-rich precipitates, and new metastable phases. The size and morphology of (Ni/sub 3/Al) phase were discussed in relation to its microchemistry and the laser-processing conditions. This paper reports the microstructural development in this laser-clad Ni-Cr-Al-Hf alloy.

• Research Organization: Illinois Univ., Urbana (USA)
• OSTI ID: 6508177
• Report Number(s): AD-A-200655/9/XAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOYS
ALUMINIUM ALLOYS
ATMOSPHERES
CHROMIUM ALLOYS
CLADDING
COATINGS
CRYSTAL STRUCTURE
DEPOSITION
DISPERSIONS
HAFNIUM ALLOYS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
LASERS
MATERIALS
MICROSCOPY
MICROSTRUCTURE
MIXING
MIXTURES
NICKEL ALLOYS
NICKEL BASE ALLOYS
PROCESSING
REFINING
SOLID SOLUTIONS
SOLUBILITY
SOLUTIONS
SURFACE COATING