Initial stage hot pressing of monosized Ti and 90% Ti-10% TiC powders

Journal Article · Mon Mar 01 04:00:00 EST 1993 · Acta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-7151(93)90030-V· OSTI ID:6238316

Taylor, N; Dunand, D C; Mortensen, A ^[1]

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1. Massachusetts Institute of Technology, Cambridge, MA (United States). Dept. of Materials Science and Engineering

The kinetics of the initial stage of uniaxial vacuum-hot-pressing of commercially pure spherical titanium powders are investigated for temperatures between 730 and 870 C and applied pressures from 25 to 50 MPa. Densification kinetics are found to agree with models of Arzt, Ashby and coworkers for hot isostatic pressing by power law creep. The best fir with all data is for a creep exponent of 4.9 and a creep activation energy of 208 kJ mol[sup [minus]1]. With the addition to the titanium powder of 10 vol.% TiC powder of same size, the densification rates remain in overall agreement with the same models but become from 5 to 20 times slower. Addition of the inert ceramic particles slows hot pressing kinetics in two ways: (1) by decreasing the initial density of the compact and (2) by reducing the densification rate at interparticle contacts. It is shown that this latter effect decreases the densification rate by a factor of at most 2 in the present experiments, hence, the former accounts for the significantly larger reductions in densification kinetics observed experimentally.

• OSTI ID: 6238316
• Journal Information: Acta Metallurgica et Materialia; (United States), Journal Name: Acta Metallurgica et Materialia; (United States) Vol. 41:3; ISSN 0956-7151; ISSN AMATEB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation & Manufacture
CARBIDES
CARBON COMPOUNDS
COMPOSITE MATERIALS
CREEP
ELEMENTS
FABRICATION
HIGH PRESSURE
HOT PRESSING
KINETICS
MATERIALS
MATERIALS WORKING
MECHANICAL PROPERTIES
METALS
POWDERS
PRESSING
TEMPERATURE RANGE
TEMPERATURE RANGE 1000-4000 K
TITANIUM
TITANIUM CARBIDES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS