Aluminum Technical Information
Aluminum Technical Information and Alloy Specs
Aluminum Die Casting has evolved from the original low pressure injection method to modern techniques which include high pressure die casting. Some of the earliest examples of aluminum die casting by pressure injection occurred in the mid 1800’s. The first patent for a die casting machine was awarded to Sturges in 1849. By 1892, other commercial applications were introduced, including cash registers and the newly invented phonograph. By the early 1900’s several mass production parts were being produced.
Aluminum die casting alloys are lightweight, offer good corrosion resistance, ease of coating, and have good mechanical properties and dimensional stability.
Aluminum castings are best used as cast or with an anodized coating and/or powder coating.
|A380||Aluminum A380 offers the best combination of casting, mechanical and thermal properties. A380 is one of the most common type of specified aluminum alloys. Aluminum 380 alloy offers very good fluidity, pressure tightness and resistance to hot cracking. Its not common to heat treat pressure die castings because of the possibility of blistering, due to sub-surface porosity when heated to elevated temperatures. There is a way to improve the properties which would be by giving castings a T2 or T5 temper. In most cases the properties of castings given a T5 temper will approach those of T6. Castings that are treated in this manner have excellent internal soundness. The machinability of A380 alloy is considered to be good.||A380: Aluminum A380 offers the best combination of casting, mechanical and thermal properties. A380 has good machinability. Good resistance to hot cracking and offers good fluidity and pressure tightness.|
One of the most common types of Aluminum alloys used.
|A384||A384 alloy is a modification of 380. Provides better die filling which improves overall cosmetics.This is particularly important where thin walls or more intricate details exist in the part design. Although it provides better filling it comes with a moderate sacrifice in mechanical properties, such as toughness.||A384: Aluminum 384 is a modification of the A380. A384 provides superior die filling capabilities which improves cosmetics.|
Chemical Composition Chart
|* Single value indicates maximum|
|** All values are percentage by weight|
lb / in³(g/cm³)
BTU / lb °F
|Coefficient of Thermal Expansion |
µ in / in°F
µ m / m°K
|Thermal Conductivity BTU / ft hr°F|
(W / m °K)
Specific Aluminum Alloy Strengths
360 – Selected for best corrosion resistance. Special alloys for special applications are available, but their use usually entails significant cost premiums.
380 – An alloy which provides the best combination of utility and cost. Approximately 95% of aluminum die castings are produced from 380 Aluminum.
383 & 384 – These alloys are a modification of 380. Both provide better die filling, but with a moderate sacrifice in mechanical properties, such as toughness.
413 (A13) – Used for maximum pressure tightness and fluidity.
|Ultimate Tensile Strength ksi (MPa)||44 (303)||46 (317)||48 (330)||43 (300)|
|25 (170)||23 (160)||24 (165)||21 (140)|
% in 2in. (51mm)
|Shear Strength |
|28 (190)||28 (190)||29(200)||25 (170)|
|Fatigue Strength |
|20 (140)||20 (140)||20 (140)||19 (130)|
|Young’s Modulus |
psi x 10 6(GPa)
|10.3 (71)||10.3 (71)||-||10.3 (71)|
|Resistance to Hot Cracking (a)||1||2||2||1|
|Die-Filling Capacity (b)||3||2||1||1|
|Corrosion Resistance (d)||2||4||5||2|
|Machining Ease & Quality (e)||3||3||3||4|
|Polishing Ease & Quality (f)||3||3||3||5|
|Electroplating Ease & Quality (g)||2||1||2||3|
|Anodizing Appearance (h)||3||3||4||5|
|Chemical Oxide Protective Coating (i)||3||4||5||3|
|Strength at Elevated Temp (j)||1||3||2||3|
(a) Ability of alloy to withstand stresses from contraction while cooling through hot-short or brittle temperature ranges.
(b) Ability of molten alloy to flow readily in die and fill thin sections.
(c) Ability of molten alloy to flow without sticking to the die surfaces. Ratings given for anti-soldering are based on nominal iron compositions of approximately 1%.
(d) Based on resistance of alloy in standard type slat spray test.
(e) Composite rating based on ease of cutting, chip characteristics, quality of finish, and tool life.
(f) Composite rating based on ease and speed of polishing and quality of finish provided by typical polishing procedure.
(g) Ability of the die casting to take and hold an electroplate applied by present standard.
(h) Rated on lightness of color, brightness, and uniformity of clear anodized coating applied in sulphuric acid electrolyte.
(i) Rated on combined resistance of coating and prolonged heating at testing temperature.
1= Most Desirable
5 = Least Desirable