Research Article
Sintering Behavior, Microstructure, and Mechanical Properties: A Comparison among Pressureless Sintered Ultra-Refractory Carbides
Table 1
Characteristics of the starting powders and lattice parameter “a’’ calculated by x-ray diffraction.
| | Powder | Crystal structure | Supplier | M. g. s. (μm) | Particle size range (μm) | BET (m2/g) | Purity (%) | Impurities (wt%) | C/M ratio | “a’’ from PDFC
Å | “a’’ from XRD
Å |
| | MoSi2 | Tetragonal | Aldrich, Milwaukee, USA | 2.8 | 0.3–5.0 | 1.6 | >99 | O : 1 | — | — | — |
| | ZrC | Cubic | Grade B, H.C. Starck, Karlsruhe, Germany | 3.8 | 0.8–8.0 | — | >99 | Cfree: 1.5
O : 0.6
N : 0.8
Fe : 0.05
Hf : 2 | 0.78 (min) | 4.692
#65-0973 | 4.698 |
| | HfC | Cubic | Cerac Inc., Milwaukee, WI, USA | 1.41 | 0.2–1.5 | 1.19 | 99.5 | U: 0.0002
Zr: <0.6 | 0.92 | 4.637
#65-0975 | 4.641 |
| | TaC | Cubic | Cerac Inc., Milwaukee, WI, USA | 1.21 | 0.2–1.5 | 0.78 | 99.5 | Ca : 0.01
Fe : 0.02
Na : 0.03
Nb : 0.03
Ti : 0.04 | 0.98 | 4.460
#65-0282 | 4.461 |
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