Alloy Specifications
Aluminum Casting
Aluminum die casting alloys are lightweight, offer good corrosion resistance, ease of casting, good mechanical properties and dimensional stability. The lightweight of aluminum is ideal for keeping manufacturing costs down. Aluminum castings are best used as-cast or with an anodize coating and/or powder-coating. For nickel, chrome and gold plating, zinc castings are suggested.
Zinc Casting
Zinc base alloys are the easiest to die cast. Ductility is high and impact strength is excellent, making these alloys suitable for a wide range of products. The flow properties of zinc alloys allow for thinner walls and longer tool life. Zinc castings are ideal for metal plating or polishing. The potential drawback to zinc alloys is the weight (approx. 2.5 times the weight of aluminum).
Chemical Composition Charts
| Zamak Die Casting Alloys | ZA Die Casting Alloys | ||||
|---|---|---|---|---|---|
| Commercial ANSI/AA | No.3 | No.5 | ZA-8 | ZA-12 | |
| Detailed Composition | |||||
| Aluminum | (Al) | 3.5-4.3 | 3.5-4.3 | 8.0-8.8 | 10.5-11.5 |
| Magnesium | (Mg) | 0.02-0.05 | 0.03-0.08 | 0.015-0.030 | 0.015-0.030 |
| Copper | (Cu) | 0.25 | 0.75-1.25 | 0.8-1.3 | 0.5-1.2 |
| Iron (max) | (Fe) | 0.10 | 0.10 | 0.075 | 0.075 |
| Lead (max) | (Pb) | 0.005 | 0.005 | 0.006 | 0.006 |
| Cadmium (max) | (Cd) | 0.004 | 0.004 | 0.006 | 0.006 |
| Tin (max) | (Sn) | 0.003 | 0.003 | 0.003 | 0.003 |
| Nickel | (Ni) | – | – | – | – |
| Zinc | (Zn) | Balance | Balance | Balance | Balance |
* Single value indicates maximum
** All values are percentage by weight
Typical Material Properties
| Zamak Die Casting Alloys | ZA Die Casting Alloys | |||
|---|---|---|---|---|
| Commercial ANSI/AA | No.3 | No.5 | ZA-8 | ZA-12 |
| Mechanical Properties | ||||
| Ultimate Tensile Strength As-Cast ksi (MPa) | 41 (283) | 48 (328) | 54 (372) | 59 (400) |
| Yield Strength As-Cast ksi (MPa) | 32 (221) | 39 (269) | 41-43 (283-296) | 21 (140) |
| Compressive Yield Strength As-Cast ksi (MPa) | 60 (414) | 87 (600) | 37 (252) | 39 (269) |
| Elongation As-Cast % in 2in. (51mm) | 10 | 7 | 6-10 | 4-7 |
| Hardness As-Cast BHN | 82 | 91 | 100-106 | 95-105 |
| Shear Strength As-Cast ksi (MPa) | 31 (214) | 38 (262) | 40 (275) | 43 (296) |
| Impact Strength As-Cast ft-lb | 43 | 48 | 24-35 | 15-27 |
| Fatigue Strength (f) As-Cast ksi (MPa) | 6.9 (47.6) | 8.2 (56.5) | 15 (103) | – |
| Young’s Modulus psi x 10 6 (GPa) | – | – | 12.4 (85.5) | 12 (83) |
| Physical Properties | ||||
| Density lb / in³ (g/cm³) | 0.24 (6.6) | 0.24 (6.6) | 0.227 (6.3) | 0.218 (6.03) |
| Melting Range °F (°C) | 718-728 (381-387) | 717-727 (380-386) | 707-759 (375-404) | 710-810 (377-432) |
| Specific Heat BTU / lb °F (J/kg °C) | 0.10 (419) | 0.210 (419) | 0.104 (435) | 0.107 (450) |
| Coefficient of Thermal Expansion µ in / in°F (µ m / m°K) | 15.2 (27.4) | 15.2 (27.4) | 12.9 (23.2) | 13.4 (24.1) |
| Thermal Conductivity BTU / ft hr°F (W / m °K) | 65.3 (113) | 62.9 (109) | 66.3 (115) | 67.1 (116) |
| Electrical Conductivity µ Ω in. | 27 | 26 | 27.7 | 28.3 |
| Poisson’s Ration | 0.30 | 0.30 | 0.30 | 0.30 |
Comparison Chart
| Zamak Die Casting Alloys | ZA Die Casting Alloys | |||
|---|---|---|---|---|
| Commercial ANSI/AA | No.3 | No.5 | ZA-8 | ZA-12 |
| Resistance to Hot Cracking (a) | 1 | 2 | 2 | 3 |
| Pressure Tightness | 1 | 2 | 3 | 3 |
| Casting Ease | 1 | 1 | 2 | 3 |
| Part Complexity | 1 | 1 | 2 | 3 |
| Dimensional Accuracy | 2 | 2 | 2 | 3 |
| Dimensional Stability | 3 | 3 | 2 | 2 |
| Corrosion Resistance | 2 | 4 | 5 | 2 |
| Resistance to Cold Defects (b) | 2 | 2 | 2 | 3 |
| Machining Easy & Quality (c) | 1 | 1 | 2 | 3 |
| Polishing Ease & Quality | 1 | 1 | 2 | 3 |
| Electroplating Ease & Quality (d) | 1 | 1 | 1 | 2 |
| Anodizing (Protection) | 1 | 1 | 1 | 2 |
| Chemical Coating (Protection) | 1 | 1 | 2 | 3 |
(a) The ability of alloy to resist formation of cold defects; for example, cold shuts, cold cracks, non-fill “woody”areas, swirls, etc.
(b) Ability of alloy to withstand stresses from contraction while cooling through the hot-short or brittle temperature range.
(c) Composite rating based on ease of cutting, chip characteristics, quality of finish, and tool life.
(d) Ability of the die casting to take and hold an electroplate applied by present standard methods.
1= Most Desirable
5 = Least Desirable
Chemical Composition Charts
| Aluminum Die Casting Alloys | |||||
|---|---|---|---|---|---|
| Detailed Composition | 360 | 380 | 384 | 413 | |
| Silicon | (Si) | 9.0-10.0 | 7.5-9.5 | 10.5-12 | 11.0-13.0 |
| Iron | (Fe) | 2 | 2 | 1.3 | 2 |
| Copper | (Cu) | 0.6 | 3.0-4.0 | 3.0-4.5 | 1 |
| Magnesium | (Mg) | 0.4-0.6 | 0.1 | 0.1 | 0.1 |
| Manganese | (Mn) | 0.35 | 0.5 | 0.5 | 0.35 |
| Nickel | (Ni) | 0.5 | 0.5 | 0.5 | 0.5 |
| Zinc | (Zn) | 0.5 | 3 | 3 | 0.5 |
| Tin | (Sn) | 0.15 | 0.35 | 0.35 | 0.15 |
| Total Others | 0.25 | 0.5 | 0.5 | 0.25 | |
| Aluminum | (Al) | Balance | Balance | Balance | Balance |
* Single value indicates maximum
** All values are percentage by weight
Typical Material Properties
| Aluminum Die Casting Alloys | ||||
|---|---|---|---|---|
| Mechanical Properties | 360 | 380 | 384 | 413 |
| Ultimate Tensile Strength ksi (MPa) | 44 (303) | 46 (317) | 48 (330) | 43 (300) |
| Yield Strength ksi (MPa) | 25 (170) | 23 (160) | 24 (165) | 21 (140) |
| Elongation % in 2in. (51mm) | 2.5 | 3.5 | 2.5 | 2.5 |
| Hardness BHN | 75 | 80 | 85 | 80 |
| Shear Strength ksi (MPa) | 28 (190) | 28 (190) | 29(200) | 25 (170) |
| Impact Strength ft-lb | – | – | 3 (4) | – |
| Fatigue Strength ksi (MPa) | 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) |
| Physical Properties | ||||
| Density lb / in³(g/cm³) | 0.095 (2.63) | 0.099 (2.74) | 0.102 (2.82) | 0.096 (2.66) |
| Melting Range °F (°C) | 1035-1105 (557-596) | 1000-1100 (540-595) | 960-1080 (516-582) | 1065-1080 (574-582) |
| Specific Heat BTU / lb °F (J/kg °C) | 0.23 (963) | 0.23 (963) | 0.23 (963) | 0.23 (963) |
| Coefficient of Thermal Expansion µ in / in°F (µ m / m°K) | 11.6 (21) | 12.2 (22) | 11.6 (21) | 11.3 (20.4) |
| Thermal Conductivity BTU / ft hr°F (W / m °K) | 65.3 (113) | 55.6 (96.2) | 55.6 (96.2) | 70.1 (121) |
| Electrical Conductivity % IACS | 30 | 27 | 22 | 31 |
| Poisson’s Ration | 0.33 | 0.33 | – | – |
Comparison Chart
| Aluminum Die Casting Alloys | ||||
|---|---|---|---|---|
| 360 | 380 | 384 | 413 | |
| Resistance to Hot Cracking (a) | 1 | 2 | 2 | 1 |
| Pressure Tightness | 2 | 2 | 2 | 1 |
| Die-Filling Capacity (b) | 3 | 2 | 1 | 1 |
| Anti-Soldering to the Die (c) | 2 | 1 | 2 | 1 |
| Corrosion Resistance (d) | 2 | 4 | 5 | 2 |
| Machining Easy & 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. | 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
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.