Alloys aluminum-containing

The uses of aluminum are similar to those of the light metals, some of which have previously been discussed under magnesium. Aluminum is also used in fabricating wire cables for electric-power transmission lines in the manufacture of kitchen utensils, furniture, and paint and in producing a wide variety of other useful articles. In connection with the general topic of alloys, attention is called to several important alloys containing aluminum. 

ASTM G 37 (Practice for Use of Mattsson s Solution of pH 7.2 to Evaluate the Stress Corrosion Cracking Susceptibility of Copper-Zinc AUoys) is an accelerated stress corrosion cracking test environment for brasses (copper-zinc alloys). The use of this test environment is not recommended for other copper alloys since the results may be erroneous, providing completely misleading rankings. This is particularly true of alloys containing aluminum or nickel as deliberate alloying additions. 

Alloy 270 is a high-purity, low-inclusion version of alloy 200. Alloy 301 (also referred to by tradename Duranickel) is a precipitation-hardenable alloy containing aluminum and titanium. Alloy 300 (also called by the tradename Permanickel) is a moderately precipitation-hardenable alloy containing titanium and magnesium that also possesses higher thermal and electrical conductivity. 

Aluminiim is the canonical a-stabiliz-ing addition against which other such additives may be compared. According to Rosenberg [Ros70], the equivalent aluminum content of an alloy containing aluminum, zirconium, tin, and oxygen is ... 

Ueh] Uehara, S., Kajiwara, S., Kikuchi, T., Origin of Abnormally Large Tetragonality of Martensite in High Carbon Iron Alloys Containing Aluminum , Mater. Trans., JIM, 33(3), 220-228 (1992) (Crys. Stmcture, Experimental, 34)... 

Lead—Calcium—Aluminum Alloys. Lead—calcium alloys can be protected against loss of calcium by addition of aluminum. Aluminum provides a protective oxide skin on molten lead—calcium alloys. Even when scrap is remelted, calcium content is maintained by the presence of 0.02 wt % aluminum. Alloys without aluminum rapidly lose calcium, whereas those that contain 0.03 wt % aluminum exhibit negligible calcium losses, as shown in Figure 8 (10). Even with less than optimum aluminum levels, the rate of oxidation is lower than that of aluminum-free alloys. 

Lead alloys containing 0.09—0.15 wt % calcium and 0.015—0.03 wt % aluminum are used for the negative battery grids of virtually all lead—acid batteries in the United States and are also used in Japan, Canada, and Europe. If the molten alloy is held at too low a temperature, the aluminum precipitates from solution, rises to the surface of the molten alloy as finely divided aluminum particles, and enters the dross layer atop the melt. 

Commercial-grade nitroparaftins are shipped and stored ia ordinary carbon steel. However, wet nitroparaftins containing more than 0.1—0.2% water may become discolored when stored ia steel for long periods, even though corrosion is not excessive. Aluminum and stainless steel are completely resistant to corrosion by wet nitroparaftins. Storage ia contact with lead (qv), copper, or alloys containing these metals should be avoided. Polymeric materials for gaskets, hoses, and connections should be tested for thek suitabiHty before exposure to nitroparaftins. 

Al—Fe. The Al—Fe system (Fig. 10), is important because virtually all commercial aluminum alloys contain some iron [7439-89-6] Fe. The system has a eutectic at 1.9% Fe, but soHd solubiHty of only 0.05% Fe. Consider an alloy containing 0.3% Fe. During solidification, most of the Fe remains ia the Hquid phase until a eutectic of soHd solution plus Al Fe constituent particles free2es. Alternatively, constituents of the metastable Al Fe phase [12005-28-6]... 

AJ—Cu. Many stmctural aluminum alloys contain significant amounts of copper [7440-50-8] Cu. There is a eutectic ia the Al—Cu system at 33.2% Cu and 548°C, but the important feature (Fig. 12) is the maximum solubiHty of 5.7% Cu at 548°C which decreases drastically at lower temperatures. 

ALkylamines are corrosive to copper, copper-containing alloys (brass), aluminum, 2inc, 2inc alloy, and galvani2ed surfaces. Aqueous solutions of aLkylamines slowly etch glass as a consequence of the basic properties of the amines in water. Carbon or stainless steel vessels and piping have been used satisfactorily for handling aLkylamines and, as noted above, some aLkylamines can act as corrosion inhibitors in boiler appHcations. 

Calcium—Silicon. Calcium—silicon and calcium—barium—siUcon are made in the submerged-arc electric furnace by carbon reduction of lime, sihca rock, and barites. Commercial calcium—silicon contains 28—32% calcium, 60—65% siUcon, and 3% iron (max). Barium-bearing alloys contains 16—20% calcium, 9—12% barium, and 53—59% sihcon. Calcium can also be added as an ahoy containing 10—13% calcium, 14—18% barium, 19—21% aluminum, and 38—40% shicon These ahoys are used to deoxidize and degasify steel. They produce complex calcium shicate inclusions that are minimally harm fill to physical properties and prevent the formation of alumina-type inclusions, a principal source of fatigue failure in highly stressed ahoy steels. As a sulfide former, they promote random distribution of sulfides, thereby minimizing chain-type inclusions. In cast iron, they are used as an inoculant. 

Sodium does not form alloys with aluminum but is used to modify the grain stmcture of aluminum—silicon alloys and aluminum—copper alloys for improved machinabiUty. Sodium—gold alloy is photoelectricaHy sensitive and may be used ia photoelectric cells. A sodium—2iac alloy, containing 2 wt % sodium and 98 wt % 2iac, is used to deoxidi2e other metals. 

The first iron—nickel martensitic alloys contained ca 0.01% carbon, 20 or 25% nickel, and 1.5—2.5% aluminum and titanium. Later an 18% nickel steel containing cobalt, molybdenum, and titanium was developed, and still more recentiy a senes of 12% nickel steels containing chromium and molybdenum came on the market. 

Compared to that prepared by cirect electron-beam melting of vanadium alloy containing 15 wt % aluminum. 

Alloys containing nickel and/or aluminum have high strength and the impact data may exhibit scatter if the cooling rate or composition has not been closely controlled. 

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