Aluminum alloys are categorized into two groups – cast aluminum and wrought aluminum alloy. These designations are based on the type or processing used to create each. At Howard Precision Metals, we are your leader for the supply of cast aluminum alloys used in making cast aluminum plate. You can trust our knowledge, experience, and resources, to help you obtain the quality aluminum cast and wrought products you need for your commercial or industrial applications.
Cast Aluminum Alloys
Cast aluminum alloys have aluminum as the primary metal with other alloying elements added. This group of alloys can be divided into heat-treatable and non-heat treatable cast aluminum alloy. In addition, these alloys have a comparatively low tensile strength, but help create cost-efficient products. The exceptional casting characteristics of this type of aluminum alloy is due to the significant presence of silicon in its composition.
Some of the beneficial characteristics of aluminum alloys that make them ideal as cast aluminum alloys include:
- Ability to control grain structure
- Good fluidity
- Low melting point
- Ability to strengthen through heat treatment
- Low solubility of gasses
- Good surface finish
At the same time, a cast aluminum alloy has some potential negative characteristics. These alloys are susceptible to shrinkage effects due to its high shrinkage characteristics. These alloys, including cast aluminum plate, also possess low ductility and are vulnerable to heat cracking. They also have a high solubility of hydrogen gas.
Wrought Aluminum Alloys
Wrought aluminum alloys also have aluminum as the primary metal. These alloys are used mostly for shaping processes such as extrusion, forging, and rolling. They are both heat-treatable and non-heat-treatable. Wrought alloys of aluminum represents about 85% of all aluminum alloys.
The alloying elements such as silicon, copper, zinc, and magnesium provide a heat-treatable alloy’s initial strength. They can be strengthened further through heat treatment. Non-heat-treatable forms have alloying elements such as silicon, manganese, and magnesium as their initial strength. These alloys can be strengthened further through strain hardening or cold working.
Differences Between Cast and Wrought Aluminum Alloys
Cast aluminum is a type of aluminum alloy with casting characteristics. Wrought aluminum, on the other hand, is ideal for shaping and machining after heat treatment.
Additional differences between these two types of aluminum alloys include:
Percentage of Alloying Elements
Wrought aluminum is an alloy that has been worked on by processes of mechanical working. These can include extrusion, rolling, and forging. On the other hand, cast aluminum is formed by the pouring of heated, molten aluminum in dies or patterns. Cast aluminum has a larger percentage of alloying elements in its constitution. In wrought aluminum, about 85% of its make up is aluminum.
Internal and External Defects
The important difference between wrought and cast aluminum alloys is that wrought aluminum alloys are usually free of external and internal defects, whereas cast aluminum alloys have many external and internal defects.
Melting Point
The melting point of cast aluminum alloy, including cast aluminum plate, is low, which gives it high cost-effectiveness, while the melting point of wrought aluminum alloy is high, giving it low cost-effectiveness.
Tensile Strength
The tensile strength of wrought aluminum alloy is higher than that of cast aluminum alloy.
Thickness
Cast aluminum alloys are typically thicker and heavier, while wrought aluminum alloys may be obtained down to a foil thickness.
Precision
Because of its low tensile strength, cast aluminum alloys achieve high precision due to the numerous external and internal defects. The ability of wrought aluminum to be processed on the other hand, allows it to undergo drilling, milling, grinding, and more, which means it is ideal for dimensional accuracy and precision parts.
Numbering Systems
There are two numbering systems for aluminum alloys. The categorizing of aluminum alloys uses a familiar four-digit number system. This system is used for the classification of wrought aluminum alloys and also a number of cast plates.
On the other hand, the classification for alloys used for the production of cast aluminum parts is different. Although this system also uses four digits, a decimal point is included between the third and fourth digits. Sometimes cast alloys are only given three numbers for their classification because the decimal is often zero.
Cast aluminum alloys offer a wider range of shapes and have a lower price per pound, while wrought aluminum alloy is better for processing with better mechanical properties. High-end applications in the aerospace and aviation fields make use of the surface finishes possible with wrought aluminum alloy.
Due to the different performance capabilities between cast and wrought aluminum alloys, they are used in different applications. Wrought aluminum can be seen in various aspects of the construction and ship building industries, and also for airframes, impellers, engine blades, landing gear parts, and propeller blades. Cast aluminum alloys are used often in the agricultural, automotive, and construction industries, including for pistons and transmissions, cylinder heads, engine boxes, hubs, instrument housings, turbine blades, window fittings, supercharger pumps, and farm equipment.
To learn about the cast aluminum plate and extruded aluminum products and services we offer at Howard Precision Metals, call us today at 800.444.0311 or request a quote.
