9

Source: Aluminum Association [5, 6].

Note: This table does not include all clad products registered with The Aluminum Association.

©Cladding composition is applicable only to the aluminum or aluminum alloy bonded to the alloy ingot or slab preparatory to processing to the specified composite product. The composition of the cladding may be subsequently altered by diffusion between the core and cladding due to thermal treatment. ©Average thickness per side as determined by averaging cladding thickness measurements taken at a magnification of 100 diameters on the cross-section of a transverse sample polished and etched for microscopic examination. ©Applicable for thickness of 0.500 in. and greater.

©The cladding component, in lieu of 4343 alloy, may be 5% lxxx Clad4343.

While the Aluminum Association cast alloy designation system uses four digits like the wrought alloy system, most similarities end there. The cast alloy designation system has three digits, followed by a decimal point, followed by another digit. The first digit indicates the primary alloying element. The second two digits designate the alloy, or in the case of commercially pure casting alloys, the level of purity. The last digit indicates the product form—1 or 2 for ingot (depending on impurity levels) and 0 for castings. A modification of the original alloy is designated by a letter prefix (A, B, C, etc.) to the alloy number. The primary alloying elements are:

lxx.x These are the commercially pure aluminum cast alloys; an example of their use is cast motor rotors. 2xx.x The use of copper as the primary alloying element produces the strongest cast alloys. Alloys of this group are used for machine tools, aircraft, and engine parts. Alloy 203.0 has the highest strength at elevated temperatures and is suitable for service at 400°F (200°C). 3xx.x Silicon, with copper and/or magnesium, are used in this series. These alloys have excellent fluidity and strength and are the most widely used aluminum cast alloys. Alloy 356.0 and its modifications are very popular and used in many different applications. High silicon alloys have good wear resistance and are used for automotive engine blocks and pistons. 4xx.x The use of silicon in this series provides excellent fluidity in cast alloys as it does for wrought alloys, and so these are well suited to intricate castings such as typewriter frames and they have good general corrosion resistance. Alloy A444.0 has modest strength but good ductility. 5xx.x Cast alloys with magnesium have good corrosion resistance, especially in marine environments (e.g., 514.0), good machinability, and can be attractively finished. They are more difficult to cast than the 200, 300, and 400 series, however. 6xx.x This series is unused.

7xx.x Primarily alloyed with zinc, this series is difficult to cast and so is used where its finishing characteristics or machinability is important. These alloys have moderate or better strengths and good general corrosion resistance, but are not suitable for elevated temperatures. 8xx.x This series is alloyed with about 6% tin and primarily used for bearings, being superior to most other materials for this purpose. These alloys are used for large rolling mill bearings and connecting rods and crankcase bearings for diesel engines.

9xx.x This series is reserved for castings alloyed with elements other than those used in the other series.

The chemical composition limits for common cast alloys are given in Table 9.5.

9.1.3.3 Tempers

Aluminum alloys are tempered by heat-treating or strain-hardening to further increase strength beyond the strengthening effect of adding alloying elements.

TABLE 9.5 Chemical Composition Limits for Commonly Used Sand and Permanent Mold Casting Alloys®®

TABLE 9.5 Chemical Composition Limits for Commonly Used Sand and Permanent Mold Casting Alloys®®

Alloy

Product©

Silicon

Iron

Copper

Manganese

Magnesium

Chromium

Nickel

Zinc

Titanium

Others

Each

Total®

0 0

Post a comment