Aluminum oxide plasma

Aluminum oxide Plasma flame spray used for extreme abrasion resistance used on steel dies but usually limited to small dies because of expansion problems works best on 18-8 stainless... 

After removal of the native aluminum oxide layer, molecular chlorine (CI2) can etch pure, clean aluminum without a plasma (84,52), Indeed, CI2 may be the primary etchant species for aluminum in a glow discharge, perhaps due to a higher concentration of CI2 than chlorine atoms in the discharge (74). 

Ingested aluminum is poorly absorbed, and there appears to be no retention of aluminum from nutritional sources in individuals with normal kidneys. Dusts of metallic aluminum and aluminum oxide are not significantly absorbed systemically, although fume from welding aluminum is absorbed through the lungs, producing a rise in aluminum levels in plasma and urine. 

Spherical alumina can also be formed from commercial, low cost aluminum-oxides or even from aluminum-hydroxides. In the latter case energy of the plasma should provide not only the enthalpy of melting but that of dehydration and subsequent phase transformations of alumina as well. Under the aforementioned conditions particles below 45 pm have a good chance to be spherodized. Presumably the wide particle size distribution of starting gibbsite powder accounts for the less spheroidization rate of 70%. 

The different PEC VD film/substrate systems are schematically presented in Figure 6a. The substrates correspond to 99.99% pure Al, mechanically polished with a 0.3 pm alumina powder, then finally electrolytically in a 70% methanol-30% nitric acid solution. When exposed to air, a native aluminum oxide of about 3 nm is produced. The substrates were coated with a dielectric film of a passivation material either SijN or Si02 4.5 wt.% P. These systems are, respectively, denoted as system A and system C. The SijN films were produced by plasma enhanced chemical vapor deposition at a temperature of 360°C, while the SiO 4.5 wt.% P films were chemically vapor deposited at a temperature of 420°C. For both passivation materials, the thickness of the films was 0.8 pm. 

Most of these discussions regarding fluorine contamination of aluminum surfaces have focused on the conversion of aluminum oxide to fluoride or oxyfluoride. Evidence for similar conversions was included, and in extreme cases conversion to aluminum bonding quite similar to that in AIF3 was found. However, the poor adhesion of the samples skipping the O2 plasma treatment is related not to the fluorine contamination as such, but rather to the carbonaceous nature of the adsorbed materials, which is subjected to the plasma polymerization of TMS. Oxygen plasma cleaning removes this carbonaceous component, while the surface fluorine concentration is enhanced. 

Cathodic plasma polymerization or LCVD of trimethylsilane (TMS) applied to an appropriately prepared aluminum alloy surface yields a roughly 50-nm-thick layer of amorphous Si C H network, which is covalently bonded to aluminum oxide at the interface [7], The XPS cross-sectional profiles given in Figure 28.10 show the conspicuous shifts in O Is and Si 2p at the interface that indicate the changes of chemical bonds. 

Tercero, J.E., Namin, S., Lahiri, D., Balani, K., Tsoukias, N., and Agarwal, A. (2009) Effect of carbon nanotube and aluminum oxide addition to plasma-sprayed hydroxyapatite coating s mechanical properties and biocompatibility. Mater. Sci. Eng. C, 29 (7), 2195-2202. 

Aluminum is used as a metallization material in current microelectronic devices. It can be etched by chlorine containing plasmas, provided that the native aluminum oxide is removed. This is accomplished with oxide scavengers such as BCI3 added to the plasma. Aluminum etching is isotropic in fact a clean aluminum surface reacts with atomic and molecular chlorine even in the absence of a plasma [225]. Anisotropy is achieved by the wall passivation mechanism (Fig. 16d). 

Flo. 47. Extinction ncheme for catecholnraines iiroin tissue or plasma using aluminum oxide. 

Ceramic coatings include a large group of subspecies, such as CVD-SiC, plasma spray deposited aluminum oxide, and plasma spray deposited... 

Polymer surfaces are modified by plasma techniques for interfacial enhancement [4-10], Au, Ag, Pd, Cu and Ni were coated on poly (methylmethacrylate) (PMMA) by barrel technique [11]. Coating of A1 alloys on PET was compared with Ti layer under A1 alloys [12]. Thin Aluminum oxide coatings have been deposited on various uncoated papers, polymer-coated papers and plain polymer films using atomic layer deposition technique [13]. The isotactic polypropylene (iPP) and A1 composite is widely used as television cable electromagnetic shielding materials [14], The reflection of infrared light depends on geometry of the surface of alumi-... 

Physical approaches are also used for synthesis of metal oxide nanoparticles. In physical vapour synthesis, a plasma is used to heat a precursor metal. The metal atoms boil off, creating a vapour. A gas is introduced to cool the vapour, which condenses into liquid molecular clusters. As the cooling process continues, the molecular clusters are frozen into solid nanoparticles. The metal atoms in the molecular clusters mix with oxygen atoms, forming metal oxides, such as aluminum oxide, smaller than 100 nm. 

Fig. 8. Aluminum oxide extraction tor brain and plasma catecholamines. Brain extraction derived from Keller et al. (1976) and Mefford (1981). Plasma extraction based on MacDonald and Falconer (unpublished).

Fig. 10. Measurement of norepinephrine and epinephrine in human plasma. Explanation of traces from left to right. A (1) Norepinephrine standard (10 pmol injected) (2) epinephrine standard (10 pmol injected) (3) dopamine standard (10 pmol injected). B (1) Plasma (1.1 ml) collected during a normoglycemic baseline period. Dopamine (10 pmol) added as internal standard prior to aluminum oxide adsorption. Sensitivity changes from 100 nA to 1 nA full scale deflection immediately after elution of the solvent front. Note the small norepinephrine (0.57 nmol/liter) and epinephrine (0.74 nmol/liter) peaks (2) plasma (1.1 ml) from the same subject, insulin-induced hypoglycemia. Note the marked increase in the epinephrine (5.16 nmol/liter) peak and the small rise in norepinephrine (0.75 nmol/liter). Dopamine (10 pmol) added as internal standard. Chromatographic conditions column, Nucleosil (10 [x), 30 cm X 2.1 mm mobile phase, acetate/citrate, 0.1 M, pH 5.2 flow rate, 1.2 ml/min electrode potential, +0.65 V (carbon paste) volume injected, 100 xl plasma extraction, alumina adsorption (Fig. 8).

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