Al-Co system

NiAl can be alloyed with further elements in order to form ternary phases with a B2 structure which is then known as an L2o structure, too, or to obtain additional phases in equilibrium with NiAl. Fe, as well as Co, can substitute for Ni in NiAl completely without affecting the B2 structure, as is expected in view of the binary B2 phases FeAl and CoAl. Correspondingly, the ternary Ni-Fe-Al phase diagram, which is of importance with respect to conventional high temperature alloys, shows the extended B2 phase field and the respective equilibria with NijAl and Al-rich phases on the one hand and with disordered b.c.c. Fe and f.c.c. Fe on the other (Bradley and Taylor, 1938 Dannohl, 1942 Bradley, 1951 Hao et al., 1984). The Ni-Al-Co system behaves in an analogous way (Hao et al., 1984 Ishida et al., 1991 a, 1993). Other ternary systems have been re-... 

Table 5.1 Total driving force per atom for the formation of intermetallic phases in the Al-Co system.

Thus, it turns out that the curvature parameter required for the numerical calculation to obtain critical gradients in the order of the experiment is quite reasonable and corresponds to the thermodynamic situation of the Al-Co system. Especially, for the polymorphic nucleation mode without shape optimization, we find almost exact agreement. The value of a = 8 x 10 J/atom for the polymorphic mode without... 

For construction of suitable samples molecular beam epitaxy was selected, the method of choice for the production of complicated epitaxial layer systems with different materials. As substrates Si wafer material (about 20x20 mm-, thickness 1 mm) and SiO, discs (diameter 30 mm, thickness 3 mm) were used. Eight layered structures (one, two and three layers) were built up with Al, Co, and Ni, with an indicated thickness of 70 nm, each. 

For alkali modified noble and sp-metals (e.g. Cu, Al, Ag and Au), where the CO adsorption bond is rather weak, due to negligible backdonation of electronic density from the metal, the presence of an alkali metal has a weaker effect on CO adsorption. A promotional effect in CO adsorption (increase in the initial sticking coefficient and strengthening of the chemisorptive CO bond) has been observed for K- or Cs-modified Cu surfaces as well as for the CO-K(or Na)/Al(100) system.6,43 In the latter system dissociative adsorption of CO is induced in the presence of alkali species.43... 

Cr-Al, Mn-Al, and Ti-Al alloys can be obtained from acidic melt solutions containing Cr(II), Mn(II), or Ti(II), respectively, only if the deposition potential is held very close to or slightly negative of the thermodynamic potential for the electrodeposition of aluminum, i.e., 0 V. From these observations it can be concluded that the formal potentials of the Cr(II)/Cr, Mn(II)/Mn, and Ti(II)/Ti couples may be equal to or less than E0 for the A1(III)/A1 couple. Unlike the Ag-Al, Co-Al, Cu-Al, Fe-Al, and Ni-Al alloys discussed above, bulk electrodeposits of Cr-Al, Mn-Al, and Ti-Al that contain substantial amounts of A1 can often be prepared because problems associated with the thermodynamic instability of these alloys in the plating solution are absent. The details of each of the alloy systems are discussed below. 

Although the activity obtained by the MA route was not the highest in this case, the effectiveness of MA was still much higher than that of conventional catalyst. In some cases, MA is more effective than rapid solidification for making supersaturated precursors. An example is the Al-Co-Cu ternary system (11). The ranking of effectiveness of these methods may in general depend on the alloy system. 

Ni and Co are immiscible elements with Ag or Cu. Especially Ag is not miscible with Ni or Co even in liquid state. Therefore, there were no previous attempts to make Raney Ni or Co with dissolved Ag and no studies on their catalytic properties, ffere, we will show an approach to make Raney Ni or Co with Cu or Ag. In the case of Al-Co-Cu system precursor, MA was an effective process to prepare a supersaturated single solid solution as shown in Fig.9 (11). The crystallographic structure after leaching of this specimen showed a broad fee phase and no other phases were observed. To examine the as-leached state, the variation of magnetization was measured with the temperature (12). Figure 10 shows the result. The magnetization... 

In the case of Al-Co-Ag, rapid solidification was effective to make a supersaturated solid solution (13). In this system, the magnetization also increased with increase of temperature and the diffraction lines of fee Co appeared upon annealing at 1073K for 3.8ks as shown in Fig. 11 (14). 

The process is not material specific, since a wide variety of materials have already been deposited such as metal powders, ceramics, glasses, and polymers (Van der Biest and Vandeperre, 1999). In general, the only shape limitation is the feasibility to remove the deposit from the electrode after deposition. Continuously graded materials in the Al203/Zr02 (Vleugels et al., 2003), Zr02/WC (Put et al., 2002), and WC/Co (Put et al., 2001) system have already been explored by means of EPD. 

Malingre MM, Beijnen JH, Rosing H, et al. Co-administration of GF120918 significantlyincreases the systemic exposure to oral paclitaxel in cancer patients. Br J Cancer 2001 84 42-47. 

POSTER TITLE STRUCTURAL EVOLUTION OF COLD COMPACTED Al-Co ALLOY SYSTEM... 

Examples of oxidative-reductive reactions under mechanical activation of systems containing hydrated oxides and any reducing agents are reported in a series of works [18-20]. For the activation of Al+Co(OH)2 mixture, divalent Co ions are partially reduced to metal state and metallic aluminium is oxidized. This is confirmed by the data obtained by means of Co NMR reported in [20]. The reduction can be represented by the equation ... 

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