Mo powder

Ellem (Ref 7) reports the. synthesis of W and Mo powder (both of which are insoluble in Zn) by mixing their oxides with a large excess of Zn dust. The powder mixt is compressed and heated to 500°, after which the process commences and completes within a few minutes. Admixture of Mg, as was done in the above Argonne National Laboratory studies, may obviate the need for high preheat temps... 

Mo blue was prepared via a modified literature procedure [14]. To a dispersion of 0.5 g Mo powder in 20 ml water was added 1 ml aqueous 35 % H2O2. After overnight stirring, and removal of residual Mo metal by filtration, the blue compound was isolated by lyophilisation of the solution. For immobilization of Mo blue on the LDH, the compound was dissolved in a minimal amount of water (e.g. 0.075 g Mo blue in 0.4 ml water), and 100 ml isopropanol was added. The LDH (1.5 g) was suspended in this solution. Visual inspection shows that after 30 minutes, uptake of the Mo blue by the LDH is essentially complete. The LDH was isolated by centrifugation and lyophilized. 

V. Ucakar, F. Chevire, F.Tessier, N. Krendelsberger, R. Marchand, W. Lengauer. Formation of molybdenum nitrides by ammonia nitridation of Mo powder and sheet // Defect Diffusion Forum.- 2001.- V.194-199.- P.1607-1612. 

Besides hydrocarbon-soluble metal complexes, solid catalysts are also employed (Mo powder, in the presence of hydroperoxides, some of this solid... 

Hydrotreating of carbon to liquid fuel Porous tubes from Ni and Mo powders, sulfided by HjS 673 129... 

Tie and Mo powders were sprayed by the plasma twin-torch process to form an FGM layer over a substrate to be used as an emitter in a thermoionic energy converter. The sprayed TiC coatings showed high absorptance for solar radiation. As compared to Tie monolayer coating and Tie/Mo two-layer coating formed on Mo substrate, FGM coatings performed better in a thermal cycling test. 

Both TiC and Mo powder feeding rates were controlled for the formation of TiC/Mo composition graded coatings. 

Formation of graded coatings (FGM) was carried out with the plasma twin torch spraying method in air. TiC and Mo powder (particle size 10 to 44 jj. m) were sprayed onto Mo substrate to obtain coatings with high thermal absorptance in order to improve the performance of the thermal energy conversion system. 

In both reactions, a molybdennm Knndsen cell was used, inside which a rough thoria cell was made by firm tamping of Th02 powder. Additional material (Th(cr) for the first reaction, and MoSi2, Th and Th02, with or without Mo powder, for the second reaction) were then added to this crade Th02 cracible. 

Rad] studied the effect of added molybdenum powder on properties of sintered fine-grained Cu-Fe alloys. The mechanical alloying was used for the preparation of the powder mixtures. The specimens were sintered in the range 600 to 1130°C. Additions of Mo powder accelerated flic sintering process. 

FIGURE 17.5 Structural changes during mechanical alloying of A1 17 at.% Mo powder in tumbler ball mill (a) crystallite size, d (b) lattice parameter of aluminum, aai (c) amorphous volume fraction, /am-... 

Mechanochemical treatment, as already emphasized, produces nanocrystalline/amorphous phases. Such pronounced metastable states readily react at elevated temperatures, thereby related equilibrium phases can be obtained relatively easily. For instance, high-temperature intermetallic compound AlgMos (melting point 2123 K), which, due to significantly different melting points of A1 and Mo is otherwise difficult to prepare from liquid phase, was obtained by continuous heating up to 1400 K of the mechanically alloyed Al-27 at.% Mo powder [46]. 

FIGURE 17.11 DSC traces of Al-lOat.% Mo powders mechanically alloyed for various milling times continuously heated at a heating rate of 20 K min . (From [75], with permission from Elsevier Science.)... 

FICU RE 17.12 Temperature (o) and enthalpy ( ) of the formation of AI12M0 intermetallic compound in mechanically alloyed Al-10 at.% Mo powders as a function of milling time. 

Peroxide. Cold 10-M H2O2 dissolves Mo powder, then forms a yellow solid, perhaps Mo02(02) H20. It also dissolves W powder, perhaps as [W203(02)4 (H20)2] -. 

---