Zamak

ZAMAK (or Zamac, formerly trademarked as MAZAK) is a family of alloys with a base metal of zinc and alloying elements of aluminum, magnesium, and copper.

Zamak alloys are part of the zinc aluminum alloy family; they are distinguished from the other ZA alloys because of their constant 4% aluminum composition.

The name zamak is an acronym of the German names for the metals of which the alloys are composed: (zinc), , , and (copper). The New Jersey Zinc Company developed zamak alloys in 1929.

The most common zamak alloy is zamak 3. Besides that, zamak 2, zamak 5, and zamak 7 are also commercially used. These alloys are most commonly die-cast. Zamak alloys (particularly #3 and #5) are frequently used in the spin-casting industry.

A large problem with early zinc-die-casting materials was zinc pest, owing to impurities in the alloys. Zamak avoided this by the use of 99.99% pure zinc metal, produced by New Jersey Zinc's use of a refluxer as part of the refining-process.

Zamak can be electroplated, wet-painted, and chromate-conversion-coated well.

Mazak In the early 1930s, Morris Ashby in Britain had licensed the New Jersey zamak alloy. The 99.99%-purity refluxer zinc was not available in Britain and so they acquired the right to manufacture the alloy using a locally-available electrolytically-refined zinc of 99.95% purity. This was given the name Mazak, partly to distinguish it from zamak and partly from the initials of Morris Ashby. In 1933, National Smelting licensed the refluxer patent with the intent of using it to produce 99.99% zinc in their plant at Avonmouth.

Standards Zinc alloy chemical composition standards are defined per country by the standard listed below:

+ Zinc alloy standards per country. Country Zinc ingot Zinc casting Europe EN1774 EN12844 US ASTM B240 ASTM B86 Japan JIS H2201 JIS H5301 Australia AS 1881 - SAA H63 AS 1881 - SAA H64 China GB 8738-88 - Canada CSA HZ3 CSA HZ11 International ISO 301 -

Zamak goes by many different names based on standard and/or country:

+ Various names for zamak alloys Traditional name Short composition name Form Common ASTM† Short European designation JIS China UK BS 1004Now defunct due to standardization of European countries under EN 1774 & EN 12844. France NFA 55-010 Germany DIN 1743-2 UNS Other Zamak 2 orKirksite ZnAl4Cu3 Ingot Alloy 2 AC 43A ZL0430 - ZX04 - Z-A4U3 Z430 Z35540 ZL2, ZA-2, ZN-002 Cast ZP0430 - Z35541 ZP2, ZA-2, ZN-002 Zamak 3 ZnAl4 Ingot Alloy 3 AG 40A ZL0400 Ingot type 2 ZX01 Alloy A Z-A4 Z400 Z35521 ZL3, ZA-3, ZN-003 Cast ZP0400 ZDC2 - Z33520 ZP3, ZA-3, ZN-003 Zamak 4 Ingot Used in Asia only ZA-4, ZN-004 Zamak 5 ZnAl4Cu1 Ingot Alloy 5 AC 41A ZL0410 Ingot type 1 ZX03 Alloy B Z-A4UI Z410 Z35530 ZL5, ZA-5, ZN-005 Cast ZP0410 ZDC1 - Z35531 ZP5, ZA-5, ZN-005 Zamak 7 ZnAl4Ni Ingot Alloy 7 AG 40B - - ZX02 - - - Z33522ZA-7, ZN-007 Cast - Z33523 †color of the cell is the color of the material designated by ASTM B908.

The short European designation code breaks down as follows (using ZL0430 as the example): Z is the material (Z=-zinc) P is the use (P=pressure-die-casting (casting), L=ingot) 04 is the percent aluminum (04=4% aluminum) 3 is the percent copper (3=3% copper)

Zamak 2 Zamak 2 has the same composition as zamak 3 with the addition of 3% copper in order to increase strength by 20%, which also increases the price. Zamak 2 has the greatest strength out of all the zamak alloys. Over time it retains its strength and hardness better than the other alloys; however, it becomes more brittle, shrinks, and is less elastic.

Zamak 2 is also known as Kirksite when gravity-cast for use as a die. It was originally designed for low volume sheet-metal-dies..Parker, Dana T. Building Victory: Aircraft Manufacturing in the Los Angeles Area in World War II, p. 86, 119, 120, Cypress, CA, 2013. . It later gained popularity for making short-run injection-molding-dies. It is also less-commonly used for non-sparking tools and mandrels for metal-spinning.

+ Zamak 2 composition per standardAlloying elementsImpurities Standard Limit Al Cu Mg Pb Cd Sn Fe Ni Si In TlASTM B240 (Ingot) min 3.9 2.6 0.025 - - - - - - - - max 4.3 2.9 0.05 0.004 0.003 0.002 0.075 - - - -ASTM B86 (Cast) min 3.5 2.6 0.025 - - - - - - - - max 4.3 2.9 0.05 0.005 0.004 0.003 0.1 - - - -EN1774 (Ingot) min 3.8 2.7 0.035 - - - - - - - - max 4.2 3.3 0.06 0.003 0.003 0.001 0.02 0.001 0.02 - -EN12844 (Cast) min 3.7 2.7 0.025 - - - - - - - - max 4.3 3.3 0.06 0.005 0.005 0.002 0.05 0.02 0.03 - -GB8738-88 min 3.9 2.6 0.03 - - - - - - - - max 4.3 3.1 0.06 0.004 0.003 0.0015 0.035 - - - -

+ Zamak 2 properties Property Metric value Imperial value Mechanical properties Ultimate tensile strength 397 MPa (331 MPa aged) 58,000 psi Yield strength (0.2% offset) 361 MPa 52,000 psi Impact strength 38 J (7 J aged) 28 ft-lbf (5 ft-lbf aged) Elongation at Fmax 3% (2% aged) Elongation at fracture 6% Shear strength 317 MPa 46,000 psi Compressive yield strength 641 MPa 93,000 psi Fatigue strength (reverse bending 5 × 108 cycles) 59 MPa 8,600 psi Hardness 130 Brinell (98 Brinell aged) Modulus of elasticity 96 GPa 14,000,000 psi Physical properties Solidification range (melting range) 379–390 °C 714–734 °F Density 6.8 kg/dm3 0.25 lb/in3 Coefficient of thermal expansion 27.8 μm/m-°C 15.4 μin/in-°F Thermal conductivity 105 W/m-K 729 BTU-in/hr-ft2-°F Electrical resistivity 6.85 μΩ-cm at 20°C 2.70 μΩ-in at 68 °F Latent heat (heat of fusion) 110 J/g 4.7 × 10−5 BTU/lb Specific heat capacity 419 J/kg-°C 0.100 BTU/lb-°F Coefficient of friction 0.08

KS The KS alloy was developed for spin casting decorative parts. It has the same composition as zamak 2, except with more magnesium in order to produce finer grains and reduce the orange peel effect.

+ KS compositionAlloying elementsImpurities Standard Limit Al Cu Mg Pb Cd Sn Fe Ni Si In TlNyrstar min 3.8 2.5 0.4 - - - - - - - - max 4.2 3.5 0.6 0.003 0.003 0.001 0.020 - - - -

+ KS properties Property Metric value Imperial value Mechanical properties Ultimate tensile strength < 200MPa < 29,000psi Yield strength (0.2% offset) < 200MPa < 29,000psi Elongation < 2% Hardness 150 Brinell max Physical properties Solidification range (melting range) 380-390°C 716-734°F Density 6.6g/cm3 0.25lb/in3 Coefficient of thermal expansion 28.0μm/m-°C 15.4μin/in-°F Thermal conductivity 105W/m-K 729BTU-in/hr-ft2-°F Electrical conductivity 25% IACS Specific heat capacity 419J/kg-°C 0.100BTU/lb-°F Coefficient of friction 0.08

Zamak 3 Zamak 3 is the de facto standard for the zamak series of zinc alloys; all other zinc alloys are compared to this. Zamak 3 has the base composition for the zamak alloys (96% zinc, 4% aluminum). It has excellent castability and long term dimensional stability. More than 70% of all North American zinc die castings are made from zamak 3.

+ Zamak 3 composition per standardAlloying elementsImpurities Standard Limit Al Cu† Mg Pb Cd Sn Fe Ni Si In TlASTM B240 (Ingot) min 3.9 - 0.025 - - - - - - - - max 4.3 0.1 0.05 0.004 0.003 0.002 0.035 - - - -ASTM B86 (Cast) min 3.5 - 0.025 - - - - - - - - max 4.3 0.25 0.05 0.005 0.004 0.003 0.1 - - - -EN1774 (Ingot) min 3.8 - 0.035 - - - - - - - - max 4.2 0.03 0.06 0.003 0.003 0.001 0.02 0.001 0.02 - -EN12844 (Cast) min 3.7 - 0.025 - - - - - - - - max 4.3 0.1 0.06 0.005 0.005 0.002 0.05 0.02 0.03 - -JIS H2201 (Ingot) min 3.9 - 0.03 - - - - - - - - max 4.3 0.03 0.06 0.003 0.002 0.001 0.075 - - - -JIS H5301 (Cast) min 3.5 - 0.02 - - - - - - - - max 4.3 0.25 0.06 0.005 0.004 0.003 0.01 - - - -AS1881 min 3.9 - 0.04 - - - - - - - - max 4.3 0.03 0.06 0.003 0.003 0.001 0.05 - 0.001 0.0005 0.001GB8738-88 min 3.9 - 0.03 - - - - - - - - max 4.3 0.1 0.06 0.004 0.003 0.0015 0.035 - - - - †Impurity

+ Zamak 3 properties Property Metric value Imperial value Mechanical properties Ultimate tensile strength 268 MPa 38,900 psi Yield strength (0.2% offset) 208 MPa 30,200 psi Impact strength 46 J (56 J aged) 34 ft-lbf (41 ft-lbf aged) Elongation at Fmax 3% Elongation at fracture 6.3% (16% aged) Shear strength 214 MPa 31,000 psi Compressive yield strength 414 MPa 60,000 psi Fatigue strength (reverse bending 5 × 108 cycles) 48 MPa 7,000 psi Hardness 97 Brinell Modulus of elasticity 96 GPa 14,000,000 psi Physical properties Solidification range (melting range) 381-387°C 718-729°F Density 6.7g/cm3 0.24lb/in3 Coefficient of thermal expansion 27.4μm/m-°C 15.2μin/in-°F Thermal conductivity 113W/mK 784BTU-in/hr-ft2-°F Electrical resistivity 6.37μΩ-cm at 20°C 2.51μΩ-in at 68°F Latent heat (heat of fusion) 110J/g 4.7 × 10−5 BTU/lb Specific heat capacity 419J/kg-°C 0.100BTU/lb-°F Coefficient of friction 0.07

Zamak 4

Zamak 4 was developed for the Asian markets to reduce the effects of die-soldering while maintaining the ductility of zamak 3. This was achieved by using half the amount of copper from the zamak 5 composition.

+ Zamak 4 composition per standardAlloying elementsImpurities Standard Limit Al Cu Mg Pb Cd Sn Fe Ni Si In TlNingbo Jinyi Alloy Material Co. min 3.9 0.3 0.03 - - - - - - - - max 4.3 0.5 0.06 0.003 0.002 0.002 0.075 - - - -

+ Zamak 4 properties Property Metric value Imperial value Mechanical properties Ultimate tensile strength 317 MPa 46,000 psi Yield strength (0.2% offset) 221-269 MPa 32,000-39,000 psi Impact strength 61 J (7 J aged) 45ft-lbf (5ft-lbf aged) Elongation 7% Shear strength 214-262 MPa 31,000-38,000 psi Compressive yield strength 414-600 MPa 60,000-87,000 psi Fatigue strength (rotary bending 5 × 108 cycles) 48-57 MPa 7,000-8,300 psi Hardness 91 Brinell Physical properties Solidification range (melting range) 380-386°C 716-727°F Density 6.6g/cm3 0.24lb/in3 Coefficient of thermal expansion 27.4 μm/m-°C 15.2 μin/in-°F Thermal conductivity 108.9-113.0W/m-K @ 100 °C 755.6-784.0 BTU-in/hr-ft2-°F @ 212°F Electrical conductivity 26-27% IACS Specific heat capacity 418.7 J/kg-°C 0.100 BTU/lb-°F

Zamak 5 Zamak 5 has the same composition as zamak 3 with the addition of 1% copper in order to increase strength (by approximately 10%), hardness and corrosive resistance, but reduces ductility. It also has less dimensional accuracy. Zamak 5 is more commonly used in Europe.

+ Zamak 5 composition per standardAlloying elementsImpurities Standard Limit Al Cu Mg Pb Cd Sn Fe Ni Si In Tl ZnASTM B240 (Ingot) min 3.9 0.75 0.03 - - - - - - - - max 4.3 1.25 0.06 0.004 0.003 0.002 0.075 - - - -ASTM B86 (Cast) min 3.5 0.75 0.03 - - - - - - - - max 4.3 1.25 0.06 0.005 0.004 0.003 0.1 - - - -EN1774 (Ingot) min 3.8 0.7 0.035 - - - - - - - - max 4.2 1.1 0.06 0.003 0.003 0.001 0.02 0.001 0.02 - -EN12844 (Cast) min 3.7 0.7 0.025 - - - - - - - - max 4.3 1.2 0.06 0.005 0.005 0.002 0.05 0.02 0.03 - -JIS H2201 (Ingot) min 3.9 0.75 0.03 - - - - - - - - max 4.3 1.25 0.06 0.003 0.002 0.001 0.075 - - - -JIS H5301 (Cast) min 3.5 0.75 0.02 - - - - - - - - max 4.3 1.25 0.06 0.005 0.004 0.003 0.01 - - - -AS1881 min 3.9 0.75 0.04 - - - - - - - - max 4.3 1.25 0.06 0.003 0.003 0.001 0.05 - 0.001 0.0005 0.001GB8738-88 min 3.9 0.7 0.03 - - - - - - - - max 4.3 1.1 0.06 0.004 0.003 0.0015 0.035 - - - -

+ Zamak 5 properties Property Metric value Imperial value Mechanical properties Ultimate tensile strength 331 MPa (270 MPa aged) 48,000 psi (39,000 psi aged) Yield strength (0.2% offset) 295 MPa 43,000 psi Impact strength 52 J (56 J aged) 38 ft-lbf (41 ft-lbf aged) Elongation at Fmax 2% Elongation at fracture 3.6% (13% aged) Shear strength 262 MPa 38,000 psi Compressive yield strength 600 MPa 87,000 psi Fatigue strength (reverse bending 5 × 108 cycles) 57 MPa 8,300 psi Hardness 91 Brinell Modulus of elasticity 96 GPa 14,000,000 psi Physical properties Solidification range (melting range) 380—386 °C 716—727 °F Density 6.6 g/cm3 0.24 lb/in3 Coefficient of thermal expansion 27.4 μm/m-°C 15.2 μin/in-°F Thermal conductivity 109 W/mK 756 BTU-in/hr-ft2-°F Electrical resistivity 6.54 μΩ-cm at 20 °C 2.57 μΩ-in at 68 °F Latent heat (heat of fusion) 110 J/g 4.7 × 10−5 BTU/lb Specific heat capacity 419 J/kg-°C 0.100 BTU/lb-°F Coefficient of friction 0.08