The importance of the material in die casting directly affects the product quality, die casting performance, and production cost of the casting.

In the die casting process, different materials have different performance characteristics. It directly affect the quality of die-casting parts, production efficiency, and the application areas of the final products.First of all, non-ferrous metals such as aluminum, zinc, and copper alloys are commonly used in die casting. Because these materials have a lower melting point and are suitable for injection into molds under high pressure.

These materials not only provide good mechanical properties but also enable high precision and complex geometries. The selection and optimization of die casting materials not only affects product quality and production efficiency. But also has great significance for environmental protection and sustainable development.

Light metal materials such as aluminum alloy and magnesium alloy have the advantages of recyclability and reuse. And meet the requirements of energy conservation and environmental protection in modern manufacturing industry.  Die casting materials play a vital role in modern manufacturing. It not only affects he quality and performance of products, but also relates to the realization of sustainable development and environmental protection goals of the industry.

• Die Casting Material Determines Mechanical Properties
• Affects Die Cast Products Accuracy and Surface Quality
• Die Casting Material Choice Affects Mold Life
• How to choose important materials for die casting
• Improve the formulation of die casting materials

Die Casting Material Determines Mechanical Properties

The chemical composition and microstructure of die casting materials directly decides casting strength, hardness, toughness, and wear resistance.

Tensile Strength and Yield Strength

• Aluminum ADC12 reaches 300-320MPa tensile strength, suitable for general structural parts
• Aluminum A356 after T6 heat treatment reaches 280MPa with 5% elongation, suitable for dynamic loads
• Zinc Zamak 3 has about 280MPa tensile strength, suitable for small to medium precision parts
• Magnesium AZ91D has high specific strength with density only 1.8g/cm³, significant lightweight effect

Hardness and Wear Resistance

• Hypereutectic aluminum A390 contains 16-18% silicon, hardness HB120, excellent wear resistance
• Copper alloy castings have thermal conductivity 380W/(m·K), suitable for heat dissipation and wear parts
• Material hardness directly affects machinability and surface treatment results

Elongation and Toughness

• Aluminum A356 has 5% elongation, suitable for impact loads
• Zinc ZA series with high aluminum content have better toughness than Zamak serries
• Brittle materials easily crack, avoid for impact parts

Affects Die Cast Products Accuracy and Surface Quality

Different alloys have different shrinkage rates, fluidity, and oxidation tendencies. These directly affect casting dimensional stability and surface finish.

Shrinkage Control

• Aluminum linear shrinkage about 0.5-0.8%, mold design needs shrinkage allowance
• Zinc shrinkage about 0.3-0.5%, good dimensional stability for precise parts
• Uneven shrinkage causes deformation, need optimized mold cooling

Fluidity Determines Forming Ability

• Aluminum-silicon alloys have best fluidity, minimum wall thickness 0.8mm
• Aluminum-magnesium alloys have poorer fluidity, need higher injection temperature and speed
• Poor fluidity causes cold shuts and incomplete filling

Surface Oxidation and Defects

• Aluminum-magnesium alloys easily oxidize, need controlled melting temperature and time
• Zinc alloys have good surface finish, direct plating possible
• Material purity affects porosity and inclusion formation

Die Casting Material Choice Affects Mold Life

Die casting materials affect mold life and production cost through thermal shock, corrosion, and wear.

Thermal Shock and Thermal Fatigue

• Aluminum casting temperature about 660-700°C, high thermal shock on molds
• Zinc casting temperature only 380-420°C, mold life up to 500,000-1,000,000 cycles
• Copper casting temperature up to 900-1000°C need special mold steels

Chemical Corrosion

• Molten aluminum erodes mold steel, iron dissolves in aluminum
• Zinc alloys have low corrosive, long mold life
• Magnesium easily react with mold steel, need surface protection

Wear and Sticking

• Hypereutectic aluminum-silicon alloys have primary silicon particles that increase mold wear
• Aluminum-magnesium alloys have high sticking tendency, need effective release agents
• Mold material must match casting material, like H13 steel for aluminum

How to choose important materials for die casting

In the die casting process, the choice of material is crucial. Because it directly affects the performance, quality, and production cost of the final product.

Here is a detailed analysis of the importance of materials in die casting:

The mechanical properties of die casting materials

Such as strength, hardness, and corrosion resistance, are key factors in determining the performance of a product.

For example, aluminum, zinc and copper alloys are often used in the die casting process. Due to the low melting point and good mechanical properties.

These materials are not only able to withstand high-pressure injection, but also provide high surface finish and dimensional accuracy.

Melting point and thermal behavior 

The melting point and thermal behavior of a material have a significant impact on the mould design and production process.

Die casting moulds are typically made of tool steel with high hardness and high temperature resistance to withstand high temperature and high pressure environments.

For example, die-casting moulds for aluminum, magnesium, and zinc alloys require the use of high-quality H13 tool steel. It can ensure mould life and product quality.

Cost-benefit analysis

The choice of materials also involves a cost-benefit analysis. For high-volume production, die casting is a cost-effective process because it reduces the need for post-processing and increases productivity.

However, for low-volume production, the high fixed cost of the mould can make die casting uneconomical. Therefore, when choosing a material, its cost-benefit ratio must be taken into account.

Different application scenarios

Different die casting materials are suitable for different industry application scenarios. For example, aluminum casting and zinc alloys are often used in the manufacture of large and small die castings due to their low cost and good flowability.

For example, like Haichen machinery in Industry application of aluminium die casting, HAICHEN engineers recommend 6063 aluminum with thermal to produce aluminum battery housing. Haichen chooses Chose Zamak 3 to produce zinc alloy door locks.

Whereas, copper alloys are suitable for applications that require higher strength and corrosion resistance due to their higher melting point and mechanical properties.

Environmental impact

The choice of materials should also take into account their environmental impact. For example, cadmium contained in zinc alloys needs to be separated and treated through a specific process to reduce environmental hazards.

Therefore, when choosing a die casting material, its environmental performance should be considered.

The processability of the material is also an important basis for selection. Die casting materials need to have good casting properties in order to smoothly fill the mould under high pressure and form high-quality castings.

For example, aluminum alloys have good casting properties and are suitable material for manufacturing cold die casting parts with complex shapes.

Improve the formulation of die casting materials

Haichen has improved its die casting material formulations to improve production efficiency and reduce costs by taking the following approaches:

Optimizing material ratios

By changing the proportions of different materials and adding other metal elements, Haichen can improve the physical and chemical properties of materials.

For example, adding small amounts of silicon and magnesium to aluminum alloys can improve the strength and toughness of the material.  

Use magnesium alloys

Magnesium alloys have lower production costs when produced in large quantities because their mould life is typically 2 to 3 times longer than that of aluminum alloys.

In addition, magnesium alloys can improve the metallurgical density and mechanical properties of parts through processes such as vacuum die casting, oxygenated die casting, semi-solid die casting and high-pressure die casting.   

Haichen adopts integrated die-casting technology

the integrated die-casting mode highly integrates multiple parts, which reduces the construction cost of the production line, the improvement of material utilization rate and the reduction of labor cost.

At the same time, the process flow is simplified and the production efficiency is significantly improved.

HAICHEN Machinery helps customers choose the best material for product needs. Through optimized injection parameters and mold design, we turn material advantages into practical productivity. Choosing HAICHEN means selecting a complete solution from material selection to process optimization.