High silicon aluminum alloys

Diamond-coated tools are primarily used in the machining of nonferrous metals, alloys, and composite materials that are inherently very difficult to cut or machine. The range of materials that are suitable for machining by diamond-coated tools include aluminum and its alloys (in particular high-silicon aluminum alloys) magnesium audits alloys copper, lead, and manganese alloys graphite carbon plastics ... 

SEAWATERa Many aluminum alleys have been show n (o resist seawater in both labwatmy controlled field tests and in service. These include alumtnum magnesium alloys 5052, 5154, 5053, 5086, and 5456 and aluminum-magneaum-silicon alloys 6061 and 6063. The high strength aluminum alloys 2219, 2024, and 7075 require protective measures when used in seawater. 

SAE 780 tin, silicon, and copper alloy, and SAE 770 using tin, copper, and nickel are aluminum alloys which have been widely used in medium- and heavy-duty diesels (6). With siUcon and cadmium incorporated for improved compatibiUty, both SAE 781 and 782 are used as an 0.5 mm to 3.0 mm overlay on a steel backing with a thin electroplated babbitt overlay. Traditional 6% tin—aluminum is also used as the SAE 780 alloy with an overlay. Eleven percent siUcon alloys are used for highly loaded diesel bearings in Europe. 

Calcium—Silicon. Calcium—silicon and calcium—barium—silicon are made in the submerged-arc electric furnace by carbon reduction of lime, silica rock, and barites. Commercial calcium—silicon contains 28—32% calcium, 60—65% silicon, and 3% iron (max). Barium-bearing alloys contains 16—20% calcium, 9—12% barium, and 53—59% silicon. Calcium can also be added as an alloy containing 10—13% calcium, 14—18% barium, 19—21% aluminum, and 38—40% silicon These alloys are used to deoxidize and degasify steel. They produce complex calcium silicate inclusions that are minimally harmfiil to physical properties and prevent the formation of alumina-type inclusions, a principal source of fatigue failure in highly stressed alloy 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. 

Clad Alloys. The heat-treatable alloys, in which copper or zinc are major alloying constituents, are less resistant to corrosive attack than a majority of the non-heat-treatable alloys. To increase the corrosion resistance of these alloys in sheet and plate form, they are often clad with a high-purity aluminum, a low-magnesium-silicon alloy, or an aluminum alloy containing 1% zinc. 

In 1925 and 1927 Raney patented a new method of preparation of an active catalyst from an alloy of a catalytic metal with a substance that may be dissolved by a solvent that will not attack the catalytic metal. First a nickel-silicon alloy was treated with aqueous sodium hydroxide to produce a pyrophoric nickel catalyst. Soon later, in 1927, the method was improved by treating a nickel-aluminum alloy with sodium hydroxide solution because the preparation and the pulverization of the aluminum alloy were easier. Some of most commonly used proportions of nickel and aluminum for the alloy are 50% Ni-50% Al, 42% Ni-58% Al, and 30% Ni-70% Al. The nickel catalyst thus prepared is highly active and now widely known as Raney Nickel, which is today probably the most commonly used nickel catalyst not only for laboratory uses but also for industrial applications.46... 

Design of cathodic protection for marine structures in both fresh and salt water require special techniques. Galvanic systems usually employ zinc or aluminum alloy anodes. Impressed current systems frequently use high silicon, chromium bearing iron, platinized niobium, or mixed-metal oxide/titanium anodes. The structure being protected affects the design. Stationary facihties such as bulkheads and support piles require different techniques from ship hulls [55]. 

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