Aluminum casting & mold design services

Driven by the global trend toward decarbonization, the automotive industry is undergoing a historic transition from internal combustion engine vehicles to electric vehicles (EVs). One of the biggest challenges for EVs is “extending cruising range,” making “lightweighting” of the vehicle body essential. However, simply reducing weight can compromise “rigidity” (resistance to deformation) and “strength,” which directly impact safety and driving performance.

In this article, we provide a thorough explanation of the latest trends in aluminum components, for which demand is skyrocketing as the EV market expands. We cover everything from “Giga Casting,” an ultra-large integrated molding technology, to technical trends in new alloys that balance high strength with lightweighting, and cost optimization strategies through overseas procurement—essential information for management and procurement heads in the Japanese manufacturing industry. Through this article, you will find insights for diversifying your supply chain and strengthening your competitive advantage.

Compared to conventional engine vehicles, EVs tend to be approximately 200kg to 300kg heavier due to the inclusion of heavy lithium-ion batteries. To offset this weight increase and improve electricity consumption (equivalent to fuel efficiency in gasoline cars), the replacement of steel with aluminum is rapidly progressing.

In the past, aluminum usage in gasoline vehicles was around 150kg per unit, centered on engine blocks and wheels. However, in next-generation EVs, its adoption is expanding to the vehicle structure (Body-in-White), battery cases, and motor housings. It is predicted that aluminum usage per vehicle will reach 250kg by 2025, making its importance as a material greater than ever before.

In recent years, attention has shifted from mere weight reduction to high strengthening through “nano-level structural control.” By refining the aluminum grain size from the conventional 10μm (micrometer) range to approximately 100–500nm (nanometers), it has become possible to improve tensile strength from 300MPa to over 350MPa without changing the specific gravity. This enables thinner-walled components, achieving both further lightweighting and enhanced safety.

Reference: Aluminum Market Trends, Size, Share, and Forecast, 2025–2032

Currently, the hottest topic in the aluminum component manufacturing field is “Giga Casting.” This technology uses massive die-casting machines (ranging from 6,000 to over 10,000 tons) to integrally mold a vehicle structure—which previously required welding dozens of steel plate parts—as a single, massive aluminum casting.

The primary benefit of Giga Casting is the dramatic improvement in production efficiency. For example, in cases promoted by Tesla and Toyota, the number of parts in the rear underbody has been reduced by more than 80, nearly eliminating complex assembly processes involving welding robots. This not only reduces the factory footprint but also improves the “fit” precision between parts, resulting in the secondary benefit of increased overall vehicle rigidity.

On the other hand, mold costs for Giga Casting-class large components can reach hundreds of millions of yen, and the risk of loss during manufacturing trouble is significant. Therefore, for Japanese procurement managers, a “Multi-Material Mix” perspective is becoming vital—not necessarily integrating everything into one, but using high-precision die casting for critical areas and combining it with cost-efficient overseas aluminum castings for peripheral parts.

For the Japanese manufacturing industry, maintaining quality while controlling costs is an eternal challenge. In particular, the surge in aluminum demand due to the EV shift can easily lead to spikes in ingot prices, highlighting the risks of relying solely on domestic procurement.

Southeast Asia, and Vietnam in particular, is drawing attention not only as a top “China Plus One” candidate but also as a strategic hub for aluminum casting. Many companies in the Vietnamese aluminum industry have received technical guidance from Japan and are establishing high-quality production systems compliant with JIS standards. Furthermore, in addition to advantages in electricity and labor costs, the tariff benefits under the Economic Partnership Agreement (EPA) with Japan are significant, often resulting in total cost reductions of 20% to 30% compared to domestic production.

The greatest concerns in overseas procurement are “quality variation” and “delivery delays.” To resolve these, it is essential to partner with a local entity that is not just an outsourcing contractor, but one that practices thorough Japanese-style Quality Control (QC) and is capable of detailed technical communication in Japanese. Utilizing a factory that practices Japanese-standard “Visualization” (Mieruka), such as Daiwa Aluminum Vietnam, directly leads to supply chain stabilization.

Trends in aluminum components for EVs have evolved beyond mere “material replacement” into a “revolution of manufacturing structures” represented by Giga Casting. The balance between lightweighting and high strength has become a reality through new alloy technologies and structural control, serving as a pillar that supports EV cruising range and safety.

What is required of Japanese procurement and purchasing heads is a “hybrid procurement strategy” that keeps a close watch on the latest technical trends while optimally combining advanced domestic technology with overseas cost competitiveness. Incorporating a rapidly growing hub like Vietnam is an extremely effective means of achieving cost reduction, BCP (Business Continuity Planning), and global competitiveness.