Recently, the "Japan Mobility Show (JMS)" was held at Tokyo Big Sight, rebranded from the Tokyo Motor Show. The last Tokyo Motor Show was held in November 2019, just before the COVID pandemic began, and for four years since then, no international motor show had been held in Tokyo. With the transformation to JMS this time, German manufacturers, who had not participated in the last Tokyo Motor Show, made their return, and the event was very successful with 1.3 million visitors.

Our company also thoroughly inspected each company's booths, and we felt that the social positioning of automobiles as a mode of transportation had significantly changed over these four years. Of course, this was due to the major shift from internal combustion engines to electrification, which has dramatically changed the positioning of mobility. The visitors to JMS were predominantly families with children, rather than the photography enthusiasts and car enthusiasts who were often the behind-the-scenes protagonists of the Tokyo Motor Show. How will automobiles relate to lifestyles and society itself over the next 40 to 50 years? JMS was a very vibrant event that firmly focused on such major themes.

■The Impact of Giga Casting
Let me highlight one impressive topic from the show. It was the aluminum cast parts created through "Giga Casting" displayed at the Toyota Motor booth. The photo at the beginning shows the rear wheel structural component of an automobile formed as a single piece by a giga casting machine. The actual product was larger than imagined and precisely molded with complex structures.

By molding such large and complex components in a single casting process, there is potential to significantly reduce the number of parts compared to previous methods. Naturally, this poses a major threat to existing related parts manufacturers. As is well known, this method was first introduced in earnest by Tesla and achieved great success. Now, Toyota and other companies are also rapidly advancing research and development to adopt this method, particularly for EV chassis.

■Elon Musk Got the Idea from a Child's Toy Car
In a recently published biography of Elon Musk (by Walter Isaacson), the inspiration behind Musk's concept of giga casting is described. Musk reportedly raised the question "Why can't this be done?" while looking at a toy car owned by his son X (formal name: X Æ A-12). Most toy cars have their bodies molded as a single piece. Musk's thinking was that real cars should be able to do the same. However, this was far removed from the conventional wisdom of automotive parts manufacturing.

■The Difference Between Casting and Forging
In automotive parts manufacturing, two methods are commonly employed: casting and forging. The differences between these two lie deeply in their manufacturing methods and product characteristics. Casting is a process where metal is melted into liquid form and poured into pre-designed molds. This method is suitable for efficiently producing parts with complex shapes and unique designs. It is commonly used for manufacturing parts suitable for large-scale production, such as automotive engine blocks and gearbox housings. However, cast parts may contain microscopic bubbles or impurities internally compared to forged parts, which can affect strength and durability. In other words, creating ultra-large parts with giga casting primarily faces strength-related challenges.

On the other hand, forging is a process where metal is heated to high temperatures and pressure is applied to change its shape. This method improves the internal structure of the metal, enhancing the strength and durability of parts. Forging is particularly preferred for heavily loaded parts such as axles and connecting rods. While forging is suitable for parts where safety is critical or high performance is required, it is more expensive and involves more complex manufacturing processes compared to casting.

■Overturning Conventional Wisdom: Successfully Molding One-Third of the Chassis as a Single Piece
Overturning this conventional wisdom, Tesla successfully achieved single-piece molding (giga casting) of ultra-large aluminum chassis. In electric vehicles, batteries are extremely heavy, so the key is how light the vehicle body itself can be made. Aluminum is a very important material for electric vehicles due to its lightweight properties, and it is also an excellent material with very high processability and recyclability.

■However, Repairs Become Difficult, Potentially Causing Maintenance Costs to Skyrocket
On the other hand, when using such large aluminum chassis, other concerns are also anticipated. For example, suppose this aluminum die-cast component cracks or becomes deformed or warped in an accident. Repairs would likely be extremely difficult. If the die-cast chassis itself needs to be replaced, repair costs could potentially be as high as the price of an entire vehicle. EVs are inherently very difficult to repair once an accident occurs. They are developed in integration with software, and the number of mechanics who can handle them is limited. Additionally, continuing to use EVs powered by lithium-ion batteries with high fire risk without proper repairs carries significant dangers. Giga casting may have the potential to manifest such risks in the future.
 

■The Threat of Further Reduction in Already Decreasing Part Counts
However, as is well known, electric vehicles replace complex internal combustion engines with motors, resulting in considerable reduction in part counts just from engine-related components. In addition to this, if the chassis itself is molded as a single piece through giga casting, parts other than the engine that have traditionally been manufactured through combinations of individual components would also see considerable reduction in part counts. Despite the risks of breakdowns and repairs, witnessing the size and precision of giga cast parts firsthand, I feel this could have an extremely significant impact, particularly on Tier 2 and Tier 3 suppliers. Whether they can achieve business remodeling, including expansion into new fields, over the next few years—the Japan Mobility Show left me feeling that many suppliers do not have much time remaining.