Introduction
In the manufacturing industry, the greatest appeal of aluminum casting lies in the multifaceted effects of its light weight. The density of aluminum is approximately 2.7 g/cm³, which is only about 34% of iron’s (approx. 7.85 g/cm³), making it possible to reduce component weight by up to 65%. For example, in a case where it was applied to automotive suspension parts, a weight reduction of about 1.5 kg per vehicle was achieved, resulting in a 1.2% improvement in fuel efficiency. In addition, it reduces energy consumption and CO₂ emissions during the logistics phase, strongly supporting sustainability management.
In terms of cost, an advantage in the total life cycle can also be expected. While the unit price of aluminum material may be about 20% higher than that of cast iron, a cost reduction of 10% or more in life cycle cost can be anticipated when including fuel cost savings from weight reduction and the shortening of downstream processes in the assembly stage. Furthermore, the naturally formed aluminum oxide film (with a thickness of about 0.01–0.1 μm) exhibits high corrosion resistance, which is another major attraction as it can suppress the additional cost of anti-rust treatment.
So, why is establishing a production base in Vietnam currently drawing particular attention? The biggest factor is the difference in wage levels. The average monthly salary for a manufacturing worker in Vietnam is about 300 USD, which is only about 10% of Japan’s approximately 3,000 USD. In addition, by taking advantage of corporate tax incentives from the local government (new investment companies are exempt from tax for the first two years and receive a 50% reduction for the following three years) and the low tariff benefits of the ASEAN Free Trade Area (FTA), it is possible to reduce overall procurement costs by about 15%. Due to these factors, Vietnam is an extremely strong option as a destination for the overseas expansion of aluminum casting.
Aluminum Casting Case Studies for Automotive Parts
Case 1: Engine Head Casting (OEM X)
OEM X switched from a conventional cast iron engine head to an A356 alloy die-cast, achieving significant improvements in both cost and delivery time. Before the switch, the component unit price was about ¥5,200 with a lead time of 21 business days. After switching to A356 alloy casting, the unit price became about ¥4,300 (a 17% reduction), and the lead time was shortened to 14 business days. With this change, the component density was reduced to 2.68g/cm³ (Si 6.5–7.5%, Mg 0.2–0.45%), making it about 35% lighter than its cast iron counterpart, achieving a weight reduction of about 2.3 kg per unit and a measured 1.5% improvement in vehicle fuel efficiency [1].
The casting conditions were a molten metal temperature of 700–720°C, a mold temperature of 160–180°C, an injection pressure of 60 MPa, and a cooling holding time of 25 seconds. After casting, a T6 heat treatment (solution treatment + artificial aging) was performed to secure a tensile strength of about 230 MPa, a Brinell hardness of HB75, and an elongation of about 4%. This resulted in quality and durability exceeding that of the conventional cast iron product [2]. In addition, an integrated production system including everything from deburring to CNC finishing was established, reducing downstream processes by 20%. Through VA/VE proposals that included dimensional optimization and gate position review, they simultaneously achieved a reduction in the defect rate and suppressed additional costs.
Case 2: EV Chassis Part Casting (Company T)
Company T began operations in Vietnam in 1997 and has now established a system with three factory die-casting lines capable of supplying parts for 4,000 vehicles per month. In response to the growing demand for EV parts, they manufacture with A357 alloy using lost-wax casting, achieving a 15% weight reduction (about 0.8 kg per part) compared to conventional products through thinning and wall thickness optimization. As a result, the total vehicle weight was reduced by about 12 kg, and the actual driving range was extended by about 4%.
By adopting a three-shift, 24-hour operation system and implementing VA/VE proposals to optimize gate positions and cooling paths, they reduced the casting defect rate by 30% and also cut processing and assembly man-hours by 10%. This initiative not only strengthens their cost competitiveness but also contributes significantly to improving EV vehicle performance.
Aluminum Casting Case Studies for Aircraft Components
Case 1: Complex-Shaped Parts via Lost-Wax Casting (Aerospace Y)
Aerospace Y mass-produces complex and high-precision aircraft components using lost-wax casting. They are fully equipped with an in-house optical emission spectrometer, Rockwell/Brinell hardness testers, and a coordinate measuring machine (CMM), and conduct non-destructive testing at each stage. By detecting minute internal defects and dimensional errors down to the micron level, they guarantee the reliability required for aircraft components [3]. Furthermore, they have obtained JIS Q 9100 (Aerospace Quality Management System) and Nadcap (Non-Destructive Testing Accreditation), and are also proceeding with preparations to obtain FAA Part 21.
Case 2: High-Heat-Resistant Alloy Casting (A357 Alloy)
The A357 alloy (approx. 7.0% Si, approx. 0.55% Mg + trace Be) used by the company achieves a tensile strength of 372 MPa, a yield strength of 317 MPa, and an elongation of 5.9% after T6 heat treatment, balancing strength and toughness in high-temperature environments [4]. By thinning and optimizing shapes through precision casting, they have reduced the proportion of machining from solid material by up to 30% and significantly compressed running costs through process consolidation. Prototype samples are delivered in as little as two weeks, and by managing lead times to within 10 weeks after transitioning to mass production, they achieve both on-time delivery and cost competitiveness.
Sources:
- CEX Casting, “A356 Aluminum,” (https://cex-casting.com/a356-aluminum/)
- eazall.com, “Mechanical Properties of A356 Alloy,” (https://www.eazall.com/a356/)
- prime.nc-net.com, “Aircraft Component Lost-Wax Casting Case Study,” (https://prime.nc-net.com/105943/ja/product/detail/246912)
- Small and Medium Enterprise Agency, “Utilization of A357 Alloy in Aircraft Components,” (https://www.chusho.meti.go.jp/keiei/sapoin/portal/seika/2007/19-29-10-3.pdf)
Aluminum Casting Case Studies for Industrial Machinery Parts
Case 1: Pump Housing Casting (Company Z)
Company Z faced technical challenges in the sand casting of large pump housings weighing over 35 kg, such as shrinkage porosity in thick sections, internal stress from cooling strains, and reduced mold life. In response, they introduced localized squeeze casting and optimized the gate position and vent design through numerical simulation¹. Furthermore, they preheated the mold to about 200°C and revised the cooling paths to control the temperature distribution, significantly reducing internal defects².
Ultimately, the housing, which underwent a heat treatment equivalent to A356-T6, achieved a tensile strength of about 255 MPa, a yield strength of about 180 MPa, and a Brinell hardness of 70–100 HB, realizing higher rigidity and durability than conventional cast iron products³.
Case 2: Gearbox Casing Casting (Company M)
Company M operates an integrated production system that spans from design and wooden pattern making in Japan to sand casting, heat treatment, and CNC machining at their Vietnam factory. This has allowed them to shorten the lead time from prototyping to mass production by about 30% compared to conventional methods⁴. They have also received customer feedback stating, “The system that allows for integrated management of quality and delivery from the design stage to mass production is highly evaluated”⁴.
Sources:
- SpringerLink, “Optimization of Large Pump Housing Casting by Local Squeeze Solidification,” (https://link.springer.com/article/10.1007/s41230-024-4061-2)
- Dongrun Casting, “Temperature Distribution Control in Large Pump Housing Casting,” (https://www.dongruncasting.com/news/How-to-Cast-Pump-Housing.html)
- AludieCasting, “Mechanical Properties of A356-T6 Material Housing,” (https://aludiecasting.com/a356-aluminum-die-casting/)
- Internal Document, “VAVE Case Study – Aluminum Casting & Machining Solutions,” L7–L12
Summary
Summary of Effects and Key Points for Each Application In the automotive parts sector, A356 alloy die-casting reduced component weight by about 2.3 kg, improving vehicle fuel efficiency by 1.5%. EV chassis parts achieved a 15% weight reduction through thinning and gate position optimization, extending the actual driving range by 4%. For aircraft components, high precision for complex-shaped parts was achieved through lost-wax casting, and a system for pressure testing and non-destructive inspection was established. For large industrial machinery parts, localized squeeze casting was adopted, achieving a tensile strength of 255 MPa and a Brinell hardness of 100 HB for A356-T6 material, significantly suppressing internal defects.
Benefits of Choosing a Vietnam Base The average monthly salary for manufacturing workers in Vietnam is low at about 300 USD (about 10% of Japan’s), and it is possible to take advantage of corporate tax incentives from the local government (tax exemption for the first two years, 50% reduction for the following three years). Furthermore, when considering the low tariff benefits from the application of the ASEAN Free Trade Area (FTA), total procurement costs can be reduced by 15–20%. Daiwa Light Alloy Vietnam has obtained IATF16949 and JIS Q 9100 certifications and, with its integrated production system, simultaneously achieves high quality, short delivery times, and low costs while maintaining Japanese quality standards.
Future Outlook and Proposals With the expected expansion of demand for EV and aerospace components, further promotion of defect rate reduction and lead time shortening can be achieved by introducing AI-driven solidification simulations and real-time quality monitoring via IoT. Additionally, customer value should be maximized by strengthening sustainability measures, such as increasing the ratio of recycled aluminum and reducing power demand in production processes.
Sources:
- Ministry of Economy, Trade and Industry, “Trade Statistics,” Export data of aluminum products to Vietnam (https://www.meti.go.jp/statistics/tyo/kougyo/result-annual.html)
- Daiwa Light Alloy Industry Vietnam Co., Ltd. Official Website (https://daiwa-vietnam.com/)
