Aluminum casting & mold design services

Introduction

In Japanese manufacturing, material selection during product development is a critically important process that significantly impacts a product’s performance, quality, cost, and market competitiveness. Especially in today’s environment, where lightweighting, high strength, and cost reduction are paramount, die-cast materials have become indispensable across a wide range of industries. Among these, aluminum die casting and zinc die casting each possess distinct characteristics and advantages, requiring appropriate selection based on application.

This guide aims to comprehensively compare and explain the physical and chemical properties, costs, productivity, and specific application examples of both aluminum and zinc die casting, enabling Japanese manufacturing executives, procurement managers, and purchasing managers to make optimal decisions in material selection. Furthermore, we will introduce the benefits and challenges of overseas procurement and the value offered by Daiwa Aluminum Vietnam, with the goal of assisting your product development and supply chain strategies.

Basic Property Comparison: Aluminum Die Casting vs. Zinc Die Casting

Aluminum die casting and zinc die casting have clear differences in their material properties, which directly affect the performance of the final product. Here, we compare their main physical and chemical properties to highlight their respective advantages.

Specific Gravity and Lightweight Properties

• Aluminum Die Casting: With a specific gravity of approximately 2.7 g/cm³, it is extremely lightweight. This is about 1/3 that of iron and 2/5 that of zinc. It offers a significant advantage in fields where lightweighting is strongly required, such as automotive and aircraft components. For example, a 10% reduction in vehicle weight is said to improve fuel efficiency by 3-6%, and aluminum’s lightweight properties also contribute to CO2 emission reduction.
• Zinc Die Casting: With a specific gravity of approximately 6.7 g/cm³, it is heavier compared to aluminum. However, this sense of weight can, in certain applications, contribute to product stability or a premium feel.

Tensile Strength and Hardness

• Aluminum Die Casting: Typical tensile strength is approximately 200-300 MPa, megapascals,. Hardness is around 70-90 HB on the Brinell scale. It offers sufficient strength while being lightweight, making it suitable for structural components. Al-Si alloys, e.g., ADC12, are particularly excellent in balancing strength and castability.
• Zinc Die Casting: Tensile strength is approximately 250-350 MPa, tending to be higher than aluminum. Hardness is also high, around 90-120 HB on the Brinell scale, and it boasts excellent wear resistance. It is suitable for precision parts and components subjected to high loads.

Melting Point and Castability

• Aluminum Die Casting: The melting point is relatively high, around 550-600°C. This means higher mold temperatures during casting, leading to greater thermal load on the molds.
• Zinc Die Casting: The melting point is lower than aluminum, around 380-420°C. Due to its low melting point, the thermal load on molds during casting is reduced, extending mold life. Furthermore, its fluidity is very high, making it suitable for casting complex shapes and thin-walled parts. Minimum wall thickness can be as thin as approximately 0.5 mm.

Thermal and Electrical Conductivity

• Aluminum Die Casting: Has very high thermal conductivity, approx. 90-170 W/m·K, offering excellent heat dissipation. It is widely used in components where heat management is crucial, such as LED lighting heat sinks and electronic device housings. Its high electrical conductivity also makes it suitable for applications requiring electrical conduction.
• Zinc Die Casting: Thermal conductivity is lower than aluminum, approx. 110 W/m·K, but still good compared to other metals. While its electrical conductivity is inferior to aluminum, it offers excellent electromagnetic shielding, EMI shielding, making it effective for noise suppression in electronic devices.

Corrosion Resistance and Need for Surface Treatment

• Aluminum Die Casting: Naturally forms an oxide film on its surface, providing excellent corrosion resistance. Furthermore, surface treatments such as anodizing, anodic oxidation film treatment, and painting can be applied to enhance corrosion resistance and aesthetic appeal.
• Zinc Die Casting: Offers relatively good corrosion resistance, but tends to corrode easily in humid, acidic, or alkaline environments. Therefore, surface treatments such as chromate conversion coating, nickel plating, and painting are commonly applied.

Vibration Damping Properties

• Zinc Die Casting: Possesses high internal damping capacity, providing excellent vibration absorption. This contributes to noise reduction in mechanical parts and suppression of fatigue failure due to vibration.
• Aluminum Die Casting: Its vibration absorption is inferior compared to zinc, but vibration countermeasures can be implemented through designs that leverage its lightweight properties.

Comparison from the Perspective of Cost and Productivity

In material selection, total cost from initial investment to mass production, as well as production efficiency, are crucial decision-making criteria.

Material Cost Fluctuations and Market Prices

• Material Costs: Generally, the international market price of zinc tends to be higher than aluminum. However, LME, London Metal Exchange, prices are constantly fluctuating. Over the past year, May 2023 – April 2024, LME aluminum prices have ranged from approximately 2,100 to 2,600 USD per ton, while zinc prices have ranged from approximately 2,300 to 3,000 USD per ton, Sources: LME Aluminum Prices, LME Zinc Prices,. Considering the specific gravity of the products, zinc tends to have higher material costs for parts of the same volume.
• Recyclability: Both materials are highly recyclable, and reusing scrap material can potentially help control material costs.

Mold Life and Initial Investment

• Mold Life: Zinc die casting has a significantly longer mold life compared to aluminum die casting due to its lower melting point, which results in less thermal load on the molds. While aluminum die casting molds typically last for tens of thousands to hundreds of thousands of shots, zinc die casting molds can last for hundreds of thousands to several million shots, and in some cases, even exceed 10 million shots.
• Initial Investment: Initial investment in mold manufacturing is high for both, but zinc die casting can potentially reduce mold costs in the long run due to less frequent mold replacement.

Production Cycle Time and Production Efficiency

• Production Cycle Time: Due to its lower melting point and shorter solidification time, zinc die casting allows for production with shorter cycle times than aluminum die casting. This increases production volume per unit of time and improves production efficiency.
• Productivity: Generally, zinc die casting is considered to have higher productivity. This is attributed to its lower casting temperature and excellent fluidity.

Need for Post-Processing and Associated Costs

• Precision: Zinc die casting offers very high dimensional accuracy, allowing for precise casting even of complex shapes. This minimizes the need for post-processing such as machining and grinding, significantly reducing post-processing costs.
• Post-Processing: While aluminum die casting can also achieve high precision, it tends to require more post-processing compared to zinc die casting. The advantage of zinc die casting is particularly pronounced for parts requiring complex internal shapes or high-precision fitting.

Yield Rate and Defect Rate

• Yield Rate: Due to its excellent fluidity and low solidification shrinkage, zinc die casting tends to maintain a high yield rate even for complex shapes.
• Defect Rate: Zinc die casting is less prone to casting defects such as internal voids and shrinkage porosity, allowing for a low defect rate. This reduces waste of material and processing costs, contributing to overall manufacturing cost reduction.

Application-Specific Selection Guide: Identifying the Optimal Material

Based on the properties, costs, and productivity of both materials, we explain key points for material selection in specific product applications.

Automotive Components

• Lightweighting Needs: Aluminum Die Casting
  Aluminum die casting is widely used for components such as engine blocks, transmission cases, suspension parts, and wheels, as vehicle lightweighting directly leads to improved fuel efficiency and reduced CO2 emissions. For example, it is not uncommon for approximately 80% of engine components to be made from aluminum die casting, Source: Japan Die Casting Association,. Especially in EVs, Electric Vehicles, further demand for aluminum die casting is expected for battery cases and motor housings.
• Complex Shapes, High Strength: Zinc Die Casting
  Zinc die casting is suitable for relatively small, complex-shaped parts requiring high strength and wear resistance, such as door lock mechanisms, seat adjustment mechanisms, and wiper components.

Electronic Device Housings

• Heat Dissipation, Lightweighting: Aluminum Die Casting
  Aluminum die casting is used for housings and internal components of products where heat management is crucial and lightweighting is required, such as smartphones, laptops, communication devices, and LED lighting heat sinks. Its excellent thermal conductivity enables efficient heat dissipation.
• Electromagnetic Shielding, Precision: Zinc Die Casting
  Zinc die casting is suitable for components requiring electromagnetic shielding, EMI shielding, and high dimensional accuracy in small precision parts, such as connectors, switch housings, and sensor cases. For example, zinc die casting is sometimes used for internal components of mobile phones to counter electromagnetic noise, Source: Japan Die Casting Association,.

Architectural Hardware and Building Materials

• Strength, Corrosion Resistance, Design Aesthetics: Aluminum Die Casting
  Aluminum die casting, with its excellent corrosion resistance and versatility in surface treatments, is suitable for products used outdoors or where design is emphasized, such as window frames, door handles, handrails, and lighting fixtures.
• High Strength, Precision: Zinc Die Casting
  Zinc die casting is chosen for hardware components requiring high strength and precise operation, such as hinges, lock parts, and internal mechanisms of door closers.

Industrial Machine Parts

• Lightweighting, Corrosion Resistance: Aluminum Die Casting
  Used for components such as pump housings, motor cases, and robot arm parts, where energy-saving effects from lightweighting or corrosion resistance in specific environments are required.
• High Strength, Wear Resistance, Vibration Damping: Zinc Die Casting
  Zinc die casting is suitable for parts subjected to high loads or requiring vibration and noise countermeasures, such as gearboxes, bearing housings, and precision mechanism components.

Medical Device Components

• Lightweighting, Cleanability: Aluminum Die Casting
  Aluminum die casting is utilized for handles of surgical instruments and housings of diagnostic devices, where lightweight and easy handling are important, and surface treatments can enhance cleanability.
• Precision, Surface Treatment, Biocompatibility: Zinc Die Casting
  Zinc die casting is considered when high dimensional accuracy and biocompatibility through specific surface treatments, e.g., electroless nickel plating, are required for small, precision medical device components and internal mechanisms of analytical instruments.

The Value Offered by Daiwa Aluminum Vietnam: Benefits of Overseas Procurement and Quality Assurance

For Japanese manufacturers aiming to enhance global competitiveness, overseas component procurement has become an unavoidable option. However, challenges such as quality, delivery time, cost, and communication also exist. Daiwa Aluminum Vietnam addresses these challenges and provides optimal solutions to our customers.

Daiwa Aluminum Vietnam’s Technical Expertise and Track Record

Daiwa Aluminum Vietnam leverages its many years of experience and know-how in die casting manufacturing to provide high-quality aluminum die-cast products. We boast an extensive track record, particularly in fields requiring high reliability, such as automotive parts, motorcycle parts, and industrial machine components. Our annual production capacity for aluminum die-cast products reaches approximately 5,000 tons, enabling us to meet diverse needs.

Quality Management System and Compliance with International Standards

We have established a rigorous quality management system compliant with ISO 9001:2015, Quality Management Systems, Source: ISO 9001:2015,. Thorough quality checks are conducted at each stage, from raw material inspection to casting, post-processing, and final inspection. We consistently maintain a defect rate below our target of 0.5%, delivering products that customers can use with confidence.

Stable Supply System and On-Time Delivery

Leveraging Vietnam’s geographical advantage, we have established a stable supply system not only within Asia but also to Japan. Through optimized supply chain management and strict production planning, we achieve an on-time delivery rate of over 98%. We flexibly respond to sudden demand fluctuations, strongly supporting our customers’ production plans.

Cost Competitiveness and Exchange Rate Risk Management

We achieve high cost competitiveness through Vietnam’s competitive labor costs and efficient production system. Regarding exchange rate fluctuation risks, we propose optimal transaction conditions for our customers, such as hedging strategies and long-term contracts, and strive to provide stable pricing. This contributes to reducing procurement costs for Japanese manufacturers.

Production System Based on Japanese Quality Standards

At Daiwa Aluminum Vietnam, we have introduced Japanese quality standards and manufacturing know-how into our Vietnamese production sites. Through guidance from Japanese engineers and training of local staff, we are able to consistently supply products of the same, or even higher, quality level as those in Japan. This eliminates concerns about quality in overseas procurement.

Technical Support from the Design Stage

We work closely with customers from the product design stage, providing technical advice on optimal shape design and material selection for die casting. This contributes to shortening development periods, reducing costs, and maximizing product performance. For example, there are cases where we achieved approximately 15% cost reduction and approximately 10% strength improvement at the initial design stage.

Conclusion

Aluminum die casting and zinc die casting each possess unique and excellent properties, and the optimal choice varies depending on the product’s application, required performance, cost, and productivity. Aluminum die casting is advantageous if lightweighting, heat dissipation, and corrosion resistance are prioritized, while zinc die casting is favorable if high strength, high precision, complex shapes, mold life, and vibration damping are emphasized.

In material selection, a comprehensive perspective that considers the entire product lifecycle, not just a single property, is essential. Taking into account material costs, mold costs, post-processing costs, production efficiency, and the market competitiveness of the final product, making optimal decisions is the key to success for Japanese manufacturers.

Daiwa Aluminum Vietnam strongly supports our customers’ product development and supply chain strategies by providing high-quality aluminum die-cast products. If you have any requirements regarding quality, delivery, cost, or technical support in overseas procurement, please do not hesitate to contact Daiwa Aluminum Vietnam. We will propose optimal solutions tailored to your needs and create the future together.