Cluster carburizing. Progress report, June 1, 1977--May 31, 1978

Technical Report · Wed Feb 01 00:00:00 EST 1978

DOI:https://doi.org/10.2172/5056319· OSTI ID:5056319

Morral, J E

When aging quenched Ta-27% Hf alloys at 685/sup 0/C, excess thermal vacancies were found to condense into vacancy loops. The loops are responsible for the first age-hardening peak observed during heat treatment. In a study of binary alloys formed by two monocarbides, a miscibility gap was found in the NbC-HfC system with a critical temperature between 1100--1200/sup 0/C, while homogeneous solutions were formed by TaC-HfC down to 1000/sup 0/C. An investigation of solid phase carburizing of Ta-Hf and Nb-Hf alloys indicated that this technique results in a higher carbon activity, but slower kinetics than was obtained by gas carburizing. Work continues on improving this technique and on preparing cluster carburized specimens for study by transmission electron microscopy.

• Research Organization: Connecticut Univ., Storrs (USA)
• DOE Contract Number: EY-76-S-02-2354
• OSTI ID: 5056319
• Report Number(s): COO-2354-5
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
HAFNIUM ALLOYS
CARBURIZATION
TANTALUM BASE ALLOYS
NIOBIUM BASE ALLOYS
AGE HARDENING
HIGH TEMPERATURE
PHASE TRANSFORMATIONS
VACANCIES
VERY HIGH TEMPERATURE
ALLOYS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
HARDENING
NIOBIUM ALLOYS
POINT DEFECTS
SURFACE HARDENING
SURFACE TREATMENTS
TANTALUM ALLOYS
360105* - Metals & Alloys- Corrosion & Erosion