Table 1.
Physical properties of study powders.
| Dphys (μm)a | Lphys (μm) | Lphys/Dphys | Dae (μm) | Mass (%)b | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Powder | Density (g/cm3) | SSA (m2/g) | AM ± SD | GM (GSD) | AM ± SD | GM (GSD) | GM | AM ± SD | GM (GSD) | I | F |
| WO3 | 7.2 ± 0.0 | 0.75 ± 0.03 | 36.2 ± 20.4 | 31.1 (1.8) | --c | -- | -- | 94 ± 53 | 80.4 (1.8) | 100 | 0 |
| WO2.98 | 7.0 ± 0.0 | 11.10 ± 0.76 | 37.5 ± 26.0 | 29.8 (2.0) | -- | -- | -- | 95 ± 66 | 75.8 (2.0) | 100 | 0 |
| WO2.81 | 7.1 ± 0.0 | 2.85 ± 0.02 | 0.3 ± 0.3 | 0.2 (2.0) | 8.8 ± 5.6 | 7.8 (1.6) | 38 | 1.7 ± 1.4 | 1.4 (1.8) | 21 | 79 |
| WO2.66 | 8.2 ± 0.0 | 1.50 ± 0.07 | 0.5 ± 0.1 | 0.5 (1.1) | 6.3 ± 0.7 | 6.3 (1.1) | 12 | 3.1 ± 0.3 | 3.1 (1.1) | 62 | 38 |
| WO2.51 | 7.7 ± 0.1 | 2.10 ± 0.02 | 0.5 ± 0.2 | 0.5 (1.5) | 7.6 ± 3.0 | 7.2 (1.4) | 15 | 3.0 ± 0.9 | 2.9 (1.4) | 21 | 79 |
| W | 19.2 ± 0.1 | 0.68 ± 0.09 | 2.5 ± 1.9 | 2.0 (2.0) | -- | -- | -- | 11.1 ± 8.1 | 8.8 (2.0) | 100 | 0 |
| Co | 8.2 ± 0.1 | 7.30 ± 0.24 | 2.4 ± 1.7 | 1.9 (1.9) | -- | -- | -- | 6.8 ± 4.9 | 5.5 (1.9) | 100 | 0 |
a Dphys = physical diameter; Lphys = physical length; Dae = aerodynamic diameter. Dae values in the Table are orientation-averaged values for the fiber-shaped fractions of the WO2.81, WO2.66, and WO2.51 powders). Calculated Dae values for the isometric-shaped particle fraction of the WO2.81, WO2.66, and WO2.51 powders are 2.5 ± 1.5, 7.5 ± 6.0, and 3.7 ± 1.8 μm, respectively.
b Particles having isometric (I)- or fiber (F)-shaped morphology
c -- Not applicable for materials of isometric morphology only