Aluminum commercially pure

Allyl alcohol, 26, 4 Allyl bromide, 25, 49 Allyl chloride, 24, 97 27, 7 Allyl cyanide, 24, 96, 97 Allyl ether, 26, 5 Allyl lactate, 26, 4 Alumina, activated, 23, 25 regeneration of, 23, 25 Aluminum, commercially pure (2S), 21, 9... 

The heavy mineral sand concentrates are scmbbed to remove any surface coatings, dried, and separated into magnetic and nonmagnetic fractions (see Separation, magnetic). Each of these fractions is further spHt into conducting and nonconducting fractions in an electrostatic separator to yield individual concentrates of ilmenite, leucoxene, monazite, mtile, xenotime, and zircon. Commercially pure zircon sand typically contains 64% zirconium oxide, 34% siUcon oxide, 1.2% hafnium oxide, and 0.8% other oxides including aluminum, iron, titanium, yttrium, lanthanides, uranium, thorium, phosphoms, scandium, and calcium. 

Atmospheric corrosion is electrochemical ia nature and depends on the flow of current between anodic and cathodic areas. The resulting attack is generally localized to particular features of the metallurgical stmcture. Features that contribute to differences ia potential iaclude the iatermetaUic particles and the electrode potentials of the matrix. The electrode potentials of some soHd solutions and iatermetaUic particles are shown ia Table 26. Iron and sUicon impurities ia commercially pure aluminum form iatermetaUic coastitueat particles that are cathodic to alumiaum. Because the oxide film over these coastitueats may be weak, they can promote electrochemical attack of the surrounding aluminum matrix. The superior resistance to corrosion of high purity aluminum is attributed to the small number of these constituents. 

Commercial tert.-butyl alcohol dried over calcium oxide is suitable for this preparation. Aluminum isopropoxide or ethoxide 2 may be used in place of the aluminum /er/.-butoxide to remove traces of water. The grade of metal known as fast cutting rods has proved most satisfactory. The checkers used turnings made from aluminum cast from melted-down kitchen utensils. Aluminum ferf.-butoxide has also been prepared successfully in another laboratory from commercially pure aluminum (2S) and from rods of the alloy 17ST (communication from L. F. Fieser). The checkers were able to obtain considerably higher yields of the butoxide from pure aluminum than from a copper-bearing alloy. 

Ondrus and Boerio also found that metallic substrates had a significant effect on the molecular structure of y-APS films cured against them [2], When y-APS films were dried against iron substrates at 110°C for 30 min, the extent of polymerization increased and the bicarbonates dissociated. Similar behavior was observed for films formed on commercially pure 1100 aluminum substrates. However, when y-APS films were dried against 2024 aluminum substrates which contain about 4.6% copper, a new band attributed to an imine formed by copper-catalyzed oxidation of the propylamine group appeared near 1660 cm 1. 

Artificial crevice electrodes have been used to study the effect of dichromate on active dissolution of aluminum. In these experiments, 50 pm thick commercially pure A1 foils were placed between thin plastic sheets and mounted in epoxy. This assembly was fixed against a square cell that accommodated counter and reference electrodes and a trap that allowed for H2 gas collection. A schematic illustration of this cell and electrode is shown in Fig. 9 (36). Crevice corrosion growth experiments were conducted in aerated 0.1 M NaCl solution with additions of either 0.01 or 0.1 M Na2Cr207. Artificial crevice growth experiments were conducted under potentiostatic polarization at potentials ranging from 0 to... 

Commercially pure aluminum has a tensile strength of 69 MPa (10,000 IbFin ), but it can be strengthened by cold working. One limitation of aluminum is that strength declines greatly above 150°C (300°F). When strength is important, 200°C (400°F) is usually considered the highest permissible safe temperature for aluminum. However, aluminum has excellent low-temperature properties it can be used at -250°C (-420°F). 

Commercially pure aluminum does not contain pure alumina but rather alumina contaminated with oxides of associated impurities, e.g. Fe, Mg, Cu, Ti, and Si, as well as oxides of alloying and modifying elements, mainly transition metals with imperfect d-shell. 

The measurement of the cavitation threshold in magnesium melts of various purity with surface protection from a flux shows the values of 0.6 to 0.8 MPa at 700 °C, which correspond well to the values of the cavitation strength of commercially pure aluminum. 

Figure 44. Electron micrograph of corroded surface of commercially pure aluminum 12 ...

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