Tungsten composites

A platinum-rhenium composite catalyst supported on the granular activated carbon (Pt-Re/C, 5 wt-Pt%, mixed molar ratio of Pt/Re = 2) [10] was prepared by a "dry-migration method" [33,34] as follows (1) The Pt/C catalyst prepared earlier (5 wt-metal%) was evacuated at 180°C for 1 h (2) The mixture (molar ratio of Pt/Re = 2) of the Pt/C catalyst and a cyclopentadienylrhenium tricarbonyl complex (Re(Cp)(CO)3) were stirred under nitrogen atmosphere at room temperature for 1 h and then heated at 100° for 1 h, with the temperature kept at a constant (3) This mixture was further stirred under hydrogen atmosphere at 240°C for 3 h and finally (4) the Pt-Re/C composite catalyst was evacuated at 180°C for 1 h. A platinum-tungsten composite catalyst supported on the granular activated carbon (Pt-W/C, 5 wt-Pt%, mixed molar ratio of Pt/W = 1) [5,6] was also prepared similarly by the dry-migration method. All the catalysts were evacuated inside the reactor at 150°C for 1 h before use. 

Manufacturing Methods for the Production of Infiltrated Tungsten Composite Rocket Nozzle Inserts , AMFL-TR-66-316 (1966) (AD 803450) 5) O. Svejka J. Kozeca, Solid Fuels for Jet, Aircraft and Ship Models , CzechP 123107... 

Palladium and tungsten composite films were prepared by simultaneous condensation of the metals and the fullerenes. The strong interaction between the metal and the fullerene led not only to charge transfer from the metal to the fullerene at the interface but also to new nanostructures in the silver and copper films. Hou et al. [113] recorded the Raman spectra of the latter as well as of a pristine fullerene film. Evidently, the metals produced new compounds with new structures, thereby reducing the symmetry of the pristine film. Unfortunately, Hou et al. did not provide information on the peak heights. It would have been interesting to note a surface enhancement of the Raman band by virtue of the metal-fullerene contact. 

Fiocchi s EMB non-toxic full-bore slugs are designed as expanding copper with elements of tungsten composite. Its two new 12-gauge slugs are 2 M at 1 oz. and 3-inch at 1 1/8 oz. 

In these expressions, E and V denote the elastic modulus and volume fraction, respectively, and the subscripts c, m, and p represent composite, matrix, and particulate phases, respectively. Figure 16.3 plots upper- and lower-bound c-versus-Vp curves for a copper-tungsten composite, in which tungsten is the particulate phase experimental data points fall between the two curves. Equations analogous to 16.1 and 16.2 for fiber-reinforced composites are derived in Section 16.5. 

Carbide Particle-Reinforced Tungsten Composites in Extreme Hazard Environments ... 

Figure 3. Schematic of the particle-reinforced tungsten composite consisting of hexagonal cylindrical cells...

Figure 5. Measured temperature curves of tungsten composites versus ablation time (a) ablated surfaces temperatures (b) backside surface temperatures...

Figure 6. Ablation properties of tungsten composites (a) linear ablation rate versus ablation time, (b) mass ablation rate versus ablation time...

Figure 7. The morphologies of tungsten composites after ablation for 120 sec...

Figure 8. Temperature fields of tungsten composite sample after heating for 1 sec (a) SOTiCAV sample, (b) 30ZrC/W sample. Temperature unit is °C.

Figure 9. Calculated temperature curves of (a) the ablated surface center and (b) backside surface center of tungsten composite samples...

The transient thermal stress field in the tungsten composite samples induced by the transient temperature field upon heating is calculated. The calculated results show the thermal stress field and the stress level of the composite sample changes seriously with heating time. It should be noted that the highest value of maximum principal stress firstly increases very fast at the heating early stage, and it appears in the sample center zone beneath the ablated surface, and then its location moves... 

The high-temperature ablation and thermal shock properties of ZrCAV and TiCAV composites are tested with an oxyacetylene equipment. Both TiC and ZrC increase remarkably tbe ablation resistance of tungsten composites. ZrCAV comoposites exhibit better ablation than TiCAV composites. 

Song, G. M., Wang, Y. J., Zhou, Y. (2003). Thermal-mechanical properties of TiC particle-reinforced tungsten composites for high temperature apphcations. International Journal of Refractory Metals Hard Materials, 27(1), 1—12. doi 10.1016/ S0263-4368(02)00105-l. 

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