Against the backdrop of global warming countermeasures and stricter fuel efficiency regulations, the automotive industry faces the urgent challenge of achieving both weight reduction and increased strength. Vehicle weight reduction contributes not only to improved fuel efficiency and reduced CO2 emissions but also to enhanced athletic performance and handling stability. Furthermore, increased strength is essential for improving collision safety and durability.
Aluminum castings are gaining attention as materials that meet these requirements. Aluminum castings are about 1/3 the weight of iron and steel, yet they combine high strength and excellent formability. Therefore, they are used in various automotive parts such as engine blocks, cylinder heads, and transmission cases.
This article introduces success stories of weight reduction and increased strength of automotive parts using aluminum castings. For each case, we will explain in detail the specific weight reduction rate, strength improvement rate, type of aluminum alloy used, manufacturing method, technical challenges, etc. Through these examples, we will explore how aluminum castings are contributing to the evolution of automobiles and their potential.
Basic Knowledge of Aluminum Cast Automotive Parts
Aluminum castings play an important role in automotive parts. Their properties meet the needs of the automotive industry in terms of weight reduction, increased strength, corrosion resistance, and recyclability.
Role and Importance of Aluminum Castings in Automotive Parts
Weight reduction of automobiles is an indispensable factor for improving fuel efficiency and reducing CO2 emissions. Aluminum castings are significantly lighter than iron and steel, and greatly contribute to the overall weight reduction of the vehicle. Furthermore, high-strength aluminum alloys developed in recent years are lightweight while having strength equivalent to or higher than conventional materials, so weight reduction can be achieved without compromising safety.
Also, aluminum has excellent corrosion resistance and is resistant to rust, which can extend the life of automotive parts. Furthermore, aluminum is a highly recyclable material, contributing to the reduction of environmental impact.
Due to these properties, aluminum castings are becoming increasingly important as a material that contributes to solving the challenges faced by the automotive industry, such as improving fuel efficiency, reducing CO2 emissions, improving athletic performance, and reducing environmental impact.
Benefits of Using Aluminum Castings
The main benefits of using aluminum castings are as follows.
- Weight Reduction: Aluminum is about 1/3 the weight of iron, which contributes to improved fuel efficiency and athletic performance by reducing the weight of automotive parts. For example, by using aluminum castings for engine parts, weight reduction of 20-30% is possible.
- Increased Strength: By using high-strength aluminum alloys, high strength can be ensured at the same time as weight reduction. This can improve collision safety and durability.
- Cost Reduction: Aluminum castings contribute to cost reduction by leading to improved efficiency in the manufacturing process and reduction in material costs. Furthermore, improved fuel efficiency due to weight reduction also leads to reduction in fuel costs.
Types of Aluminum Castings and Application Examples for Automotive Parts
There are mainly three types of aluminum castings.
- Sand Mold Casting: A casting method that uses sand as a mold material, suitable for manufacturing parts with complex shapes. Used for engine blocks and cylinder heads.
- Die Casting: A casting method in which molten aluminum is injected into a metal mold at high speed and high pressure, suitable for mass production of high-precision parts. Used for transmission cases and wheels.
- Other Casting Methods: Lost wax casting, continuous casting, etc. Lost wax casting is suitable for manufacturing parts with precise shapes, and continuous casting is suitable for mass production of parts with constant shapes.
By properly using these casting methods, various types of automotive parts can be manufactured efficiently.
Success Stories of Aluminum Cast Automotive Parts
Based on Perplexity’s search results, we will divide the application examples of aluminum alloys to automotive parts into three categories, and introduce specific examples.
1. Steering Parts
Tie rod ends, steering parts that traditionally used iron for strength, are increasingly being replaced by aluminum due to advances in high-strength aluminum forging technology. High-strength aluminum forging is a technology that improves strength by proprietary high-speed constant-temperature forging, achieving strength comparable to iron. This makes it possible to reduce the weight of steering parts while ensuring the necessary strength. As the world’s first mass-produced aluminum tie rod end for automobiles, it contributes to improving the fuel efficiency and cruising range of EVs [1].
2. Vehicle Body Structure
Tesla has achieved significant weight reduction of the vehicle body by introducing an ultra-large die-casting machine called “Giga Press” and manufacturing large automotive parts from aluminum [2]. Die casting is a casting method in which molten metal is injected into a mold under pressure, and is attracting attention as a technology that contributes to vehicle weight reduction. Aluminum alloys are often used as die-casting materials because of their low density, excellent corrosion resistance, and workability. In die-casting, parts without joints can be manufactured, making it possible to reduce weight while maintaining high part rigidity. Furthermore, even parts with complex shapes can be formed with high precision by injecting metal into a mold [2].
3. Housings
Magnesium die casting is used for the housing of the unit part of electrically power assisted bicycles [2]. Magnesium alloys, which have a higher specific gravity and higher rigidity than aluminum, are used for parts that require strength, achieving both weight reduction and strength retention.
As these examples show, aluminum alloys are applied to various automotive parts, contributing to weight reduction. Especially in EVs, aluminum plays an important role in suppressing weight increase due to battery mounting and extending cruising range [1, 3].
Source:
[1] High-Strength Aluminum Forged Tie Rod End – NEDO: https://www.nedo.go.jp/
[2] Why Tesla builds car bodies with “Giga Press”? The forefront of EV parts weight reduction: https://xtech.nikkei.com/
[3] The forefront of “aluminum material” technology that holds the key to EV proliferation: https://tech.nikkeibp.co.jp/
1 https://www.t-turret.co.jp/forging/product/aluminum/ev/
2 https://diecasting.atryz.co.jp/knowledge/knowledge_9/
3 https://www.shisaku.com/blog/anatomy/post-100.html
Technological Trends in Aluminum Cast Automotive Parts
Aluminum casting technology, which leads the way in reducing the weight and increasing the strength of automotive parts, continues to evolve. The following are some of the technological trends that have attracted particular attention in recent years.
Development of High-Strength Alloys
The development of new alloy components and composite materials is active in order to achieve further weight reduction and higher strength of automotive parts. For example, alloys with improved strength and heat resistance have been developed by adding silicon, magnesium, etc. to aluminum. Composite materials such as carbon fiber reinforced aluminum (CFRA) are also being studied, and it is expected to achieve both weight reduction and high strength. These high-strength alloys are being applied to parts used in more severe environments, such as engine parts and vehicle body structural members.
Evolution of Casting Technology
Casting technology is also evolving to produce higher quality and more complex shaped parts. Mold production using 3D printing technology enables the manufacture of parts with complex shapes that were difficult with conventional manufacturing methods, more quickly and at lower cost. Precision casting technology and wall thinning technology contribute to weight reduction and performance improvement of parts. Furthermore, quality control systems utilizing smart factories and IoT (Internet of Things) have been introduced, and automation and quality stabilization of the casting process are progressing.
Evolution of Joining Technology
Joining with other parts is essential for incorporating aluminum cast parts into automobiles. Joining technology is also evolving, and various technologies such as friction stir welding (FSW), adhesive joining, and dissimilar material joining have been developed. FSW is a method of joining metals using frictional heat, and can achieve high-strength and highly airtight joints. Adhesive joining is a method of joining parts using an adhesive, and contributes to weight reduction. Dissimilar material joining is a method of joining aluminum with other materials (e.g., iron or resin) and improves the functionality of parts.
Future Outlook
Aluminum cast automotive parts technology is expected to evolve in the following directions in the future.
- Further Weight Reduction and Higher Strength: Further weight reduction and higher strength of automotive parts will be achieved through the development of new alloys and composite materials, the evolution of casting technology, and the sophistication of joining technology.
- Parts Development Compatible with Electrification and Autonomous Driving: With the spread of electric vehicles and autonomous vehicles, the development of new parts such as battery cases, motor housings, and sensor parts is required. Aluminum casting technology is expected to contribute to the weight reduction and higher strength of these parts.
- Efforts to Reduce Environmental Impact: Efforts to reduce environmental impact, such as reducing energy consumption in the aluminum casting manufacturing process and developing recycling technology, will accelerate.
Based on these technology development trends, Daiwa Keikinzoku will leverage its strengths such as cost reduction through production in Vietnam, high quality through Japanese-style management, and local procurement in Vietnam to provide high-quality aluminum cast parts that meet the needs of the automotive industry.
Aluminum Cast Automotive Parts Manufacturers
Introduction of Major Manufacturers
There are many manufacturers of aluminum cast automotive parts both domestically and internationally. The following are representative manufacturers, their strengths, specialties, and major customers.
- Alcoa: A major American aluminum manufacturer that provides aluminum products to a wide range of industries such as aerospace, automotive, and packaging. In the automotive sector, it has strengths in the development of high-strength aluminum alloys, die-casting technology, and joining technology. Major customers include Ford, GM, and Toyota.
- Lynden: A Canadian automotive parts manufacturer that specializes in die-cast parts. It offers a wide range of products such as engine blocks, transmission cases, and chassis parts, and mainly trades with North American automakers.
- UACJ: A Japanese aluminum rolling and processing manufacturer that provides aluminum products to a wide range of fields such as automobiles, aircraft, and electronic equipment. In the automotive sector, it has strengths in heat exchangers and structural materials, and mainly trades with Japanese automakers.
- Ahresty: A Japanese die-casting manufacturer that provides a wide range of products such as automotive parts, motorcycle parts, and industrial machinery parts. It has strengths in manufacturing high-quality die-cast products and trades with domestic and international automakers.
Manufacturer Contribution Examples
Aluminum cast parts manufacturers are engaged in various technology development and initiatives to contribute to the weight reduction, increased strength, and reduced environmental impact of automobiles.
- Technology Development Examples Contributing to Weight Reduction and Increased Strength:
- Development of High-Strength Aluminum Alloys: By developing alloys with higher strength than conventional aluminum alloys, it is possible to reduce the weight of parts.
- Evolution of Die-Casting Technology: By developing die-casting technology that can manufacture parts with more complex shapes, it contributes to weight reduction and improved functionality of parts.
- Development of Joining Technology: By developing technology to join aluminum with other materials, it enables improved part strength and diverse functionality.
- Initiatives Contributing to Reduced Environmental Impact:
- Use of Recycled Materials: By actively using recycled aluminum materials, it contributes to effective use of resources and reduction of CO2 emissions.
- Reduction of Environmental Impact in the Manufacturing Process: It promotes initiatives to reduce environmental impact, such as reducing energy consumption and waste in the manufacturing process.
Through these technology development and initiatives, aluminum cast parts manufacturers are greatly contributing to the development of the automotive industry.
Summary
Weight reduction and increased strength of aluminum cast automotive parts are indispensable for improving automobile fuel efficiency, reducing CO2 emissions, and improving athletic performance. Automakers such as Toyota and Ford are actively adopting aluminum castings and enjoying various benefits from weight reduction and increased strength.
Aluminum casting technology is constantly evolving, including the development of high-strength alloys, the evolution of casting technology, and the sophistication of joining technology. In the future, it will continue to contribute to solving problems such as further weight reduction and higher strength, compatibility with electrification and autonomous driving, and reduction of environmental impact.
Aluminum castings will further expand their potential as an important material that supports the sustainable development of the automotive industry.
