Let’s look at some of the fundamental aspects you need to know about Zamak 7 alloy.
- What Is The Composition Of Zamak 7?
- What Are The Properties For Zamak 7?
- Where Is Zamak 7 Material Applied?
- How Does Zamak 7 Compare To Zamak 3?
- What Are The Benefits Of The Zamak 7?
- How Can You Check Quality Of Zamak 7?
- Is Zamak 7 Suitable For Die Casting?
- What Are Limitations Of Zamak 7?
- How Strong Is Zamak 7?
- How Does Zamak 7 Compare To Aluminum Alloys?
What Is The Composition Of Zamak 7?
Zamak 7
Zamak 7 also known as Zinc alloy 7 is a combination of aluminum, magnesium and copper with zinc acting as base material.
It derives its name from its material’s set composition range; Zinc (Z), Aluminum (A), Magnesium (MA), Kupfer (Copper).
Zamak 7 alloy contains less quantities of magnesium with better ductility than Zamak 3 thus is considered a high-purity alloy. The added alloys impurities are controlled by adding small quantities of nickel which also reduces inter-granular corrosion.
The elements which make up Zamak 7 material include the following and in a given quantity as follows:
Element | Quantity in percentage (%) | Element Properties |
Aluminum (Al) | 3.5-4.3 | |
Copper (Cu) | 0.25 | |
Iron (Fe) | 0.075 max | |
Nickel (Ni) | 0.005-0.02 | Controls impurities |
Magnesium (Mg) | 0.005-0.02 | Low Mg Increases fluidity |
Lead (Pb) | 0.003 max | |
Cadmium(Cd) | 0.002 max | |
Tin (Sn) | 0.002 max | |
Zinc (Zn) | Balance |
What Are The Properties For Zamak 7?
Zamak 7 possesses physical, chemical and mechanical properties due to its element composition.
Physical properties of Zamak 7 are as follows measured in metric and imperial values;
Physical property | Metric value | Imperial value |
Melting range | 381—387 °C | 718—729 °F |
Coefficient of thermal expansion | 27.4 μm/m-°C | 15.2 μin/in-°F |
Thermal conductivity | 113 W/m-K | 784 BTU-in/hr-ft2-°F |
Electrical resistivity | 6.4 μΩ-cm | 2.5 μΩ-in |
Specific heat capacity | 419 J/kg-°C | 0.100 BTU/lb-°F |
Casting temperature | 395—425 °C | 743—797 °F |
The chemical properties of Zamak 7 include the individual elements which make up zinc alloy 7 unique. Each element possesses a unique property that affects the final property of Zamak 7.
Mechanical properties of Zamak 7 contribute to its application in different areas such as in manufacturing of appliances, die cast toys, etc.
Some of those properties include:
Mechanical property | Metric value | Imperial value |
Brinell hardness | 80 | 80 |
Shear strength | 214MPa | 31,000 psi |
Elongation at fracture | 13-14% | |
Comprehensive yield strength | 221MPa | 32Psi |
Impact strength | 58.0 J | 42.8ft-lbf |
Fatigue strength (reverse bending 5×108 cycles) 47.0 MPa | 6,820psi | |
Yield strength | 285 MPa | 41,300 psi |
Ultimate Tensile strength | 285MPa | 41,300 psi |
Where Is Zamak 7 Material Applied?
Zamak 7 is highly ductile, fluid and with improved surface finish as a result of the strictly controlled alloy impurities.
It is therefore applied in different areas such as:
- Die casting for making thin walled components necessary for good surface finish.
- Manufacture of some firearms
- Used for damping and vibration attenuation
- Making of appliances such as door locks, handle, key chains, etc.
How Does Zamak 7 Compare To Zamak 3?
Zamak 7 and Zamak 3 are both zinc alloys composed of different alloy components with zinc as the base metal.
Zamak 7 however has low content of magnesium (0.02) element thus making it more fluid compared to Zamak 3 (0.05).
Both Zamak 7 and Zamak 3 have aluminum content of 4% with the other elements contents varying.
Zamak 3 is the standard zinc alloy due to its balanced element composition, physical and mechanical properties. As a result, Zamak 3 is widely used in die casting due to stability and longevity compared to Zamak 7.
What Are The Benefits Of The Zamak 7?
Zamak 7 boost of several advantages due to its mechanical and physical properties such as rigidity, strength and toughness. All this combined property contributes to better performance and economical castability.
- Strength and ductility
Zamak 7 is highly strong and with superior elongation properties thus making it formidable for use in designs and bending operations.
- Rigidity
Zinc alloys are rigid and equally elastic in characteristic just like other materials. However, their level of rigidity is far superior than other die cast.
- Toughness
Zamak 7 is highly resistance to impact and strong compared to other materials like plastics, aluminum alloys and grey cast iron.
- Anti-sparking
Zinc alloy is non-sparking making Zamak 7 ideal for use in hazardous areas such as coal miners, refineries, etc.
- Easy finishing
Zamak 7 casting material can be easily polished, chromate or anodized or plate painted for decorative purposes.
- Long shelf-life
Zamak 7 has low casting temperature making it experience less thermal shock when working with it. This extends the casting life of zinc alloys compared to aluminum alloy.
- Thin wall castability
Thin wall castings can be made on zinc due to high-casting fluidity of Zamak 7.
- Machinability
Due to trouble free mechanization of zinc material without wear and tear during use, makes it a great tool.
- Recyclable
Zinc alloy are known to have clean melting points which is toxic free making it a recyclable and reusable material.
How Can You Check Quality Of Zamak 7?
One of the ways to confirm the quality of Zamak 7 is by checking its elements quantities.
Excessive presence of impurities will interfere with the corrosive property hence making it loose this characteristic.
Zamak 7
Is Zamak 7 Suitable For Die Casting?
Yes, it is.
This is because Zamak 7 is has high fluidity thus allowing thin wall casting regardless of the process.
What Are Limitations Of Zamak 7?
- Zamak 7 is heavy in weight hence it is not applicable in lightweight operations.
- Very high temperature can easily damage zinc casting tensile strength making it fragile.
- The impact strength of Zamak 7 decreases significantly with a drop in temperature.
- Other elements in excess quantities such as lead and tin decreases its corrosive property.
How Strong Is Zamak 7?
Zamak 7 has an ultimate tensile strength of 41,300 psi which makes using it during bending, elongation operations possible.
Besides, they have an impact resistance of 58.0 J making them tougher than other alloys such as aluminum alloys.
How Does Zamak 7 Compare To Aluminum Alloys?
- Zamak 7 is made from zinc alloys classification and other elements in different quantities with zinc as base material. Aluminum alloys is derived from aluminum alloy classifications and other elements.
- Zamak 7 die casting is easier to achieve without additional machining compared to aluminum alloy casting.
- Zamak 7 has excellent corrosion resistance compared to aluminum alloy.
- Zamak 7 has better mechanical properties than aluminum alloy.
- Zamak 7 has better fluidity than aluminum alloy thus can be used to make thinner parts of die casting.
- Zamak 7 is a heavy weight material and durable whereas aluminum alloy is light weighted structural material.
For any questions or inquiry about zinc die casting, contact u snow.