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Microstructure and preparation of an ultra-fine-grained W-Al2O3 composite via hydrothermal synthesis and spark plasma sintering.
- Source :
-
International Journal of Refractory Metals & Hard Materials . Apr2018, Vol. 72, p149-156. 8p. - Publication Year :
- 2018
-
Abstract
- Metal-matrix composite powders of W with Al 2 O 3 reinforcements were synthesized by a novel hydrothermal route, which includes calcination and hydrogen reduction steps. It was found that the pH value and reactant concentration in the hydrothermal reaction had a significant influence on the morphology and particle size of the powders produced. The precursor powder particle size was the smallest for pH values of < 1.0 and a reactant concentration of 0.5 g/ml. The addition of Al 2 O 3 led to significant refinement of W particles produced via this route, and these particles gradually become more spherical with increasing Al 2 O 3 content. Subsequently, bulk Al 2 O 3 -reinforced W composites were fabricated by spark plasma sintering. The Al 2 O 3 content was varied from 0 to 15 vol%, and sintering was performed under 30 MPa pressure for 5 min at temperatures of 1800–2100 °C. The density of the sintered samples increased with sintering temperature, reaching a value of about 97% of the theoretical value for a sintering temperature of 1900 °C. An increase in the Al 2 O 3 content from 0 to 6 vol% resulted in an increase in the micro-hardness of the sintered composite samples from 278 to 423 HV and a decrease in the W grain size from 4.25 to 2.78 μm. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 02634368
- Volume :
- 72
- Database :
- Academic Search Index
- Journal :
- International Journal of Refractory Metals & Hard Materials
- Publication Type :
- Academic Journal
- Accession number :
- 127985841
- Full Text :
- https://doi.org/10.1016/j.ijrmhm.2017.12.022