Making something lighter is a never ending quest. If a vehicle is lighter, it exerts fewer loads on the engine which in turn contributes to improved fuel efficiency, less CO2 emissions and pollutants. Weight reduction can also improve key performance characteristics including acceleration, steering and braking. However, on the other hand, the addition of safety and convenience features generally adds weight making the vehicle heavier. The unstoppable transition toward electrification requires a large battery and electric motor which makes vehicles heavier. At the same time, fuel efficiency and environmental regulations in the European and North American market are strengthening bringing additional challenges.
All these changes are increasing the need for lightweight materials which can defy the rules of tradeoff between weight and strength, so that the joy of driving can be preserved while complying with regulations. This is why it is crucial to develop and employ lightweight materials tailored for different parts of the vehicle. The key obstacle to this approach is the high cost of high-strength lightweight composite materials. HMG is already developing third generation ultrahigh strength steels, aluminum, composite plastics and Carbon Fiber Reinforced Plastics, which is regarded as the ultimate lightweight material, with a focus on cost reduction and in-house capacity building.
In-House Developed Lightweight
Materials; A Key to
Competitiveness
Lightweight materials technology has an important role to play in the fast-changing automobile business, which is currently facing an exciting transition to a new type of mobility. The development of new lightweight materials and technologies and processes for production will serve as the foundation for product competitiveness. The polymer materials research lab is working to secure in-house production capacity of new lightweight materials to prepare HMG for the future mobility market.
Q. There is an increasing focus on lightweight materials. What is the significance of lightweight materials in today’s automobile industry?
Lightweight technology directly affects product competitiveness because weight reduction contributes to improvement of both vehicle performance and fuel efficiency. Lightweight materials can serve as the foundation for achieving weight reduction.
It is difficult to achieve strong performance with a heavy car. Increasingly stringent emission standards are also another reason why weight reduction is becoming more important. Companies cannot sell cars if they do not meet regulatory standards. Reductions in vehicle weight allow the engine to work less which in turn leads to a reduction in emissions. Lightweight is the key to survival.
It is also important to emphasize that reduction in weight of one part leads to more reduction. For example, trunk lids made using lighter steel allow for a downsizing of the electric motor for the liftgate because less power is required for operation. The same is true for other parts such as the trunk hinge because it needs to support less weight. The importance of lightweight materials will only continue to increase over time.
Q. The number of parts in a car is expected to decrease significantly as internal combustion engines are phased out. Doesn’t it make lightweight technology less important?
The number of parts is less in EVs but they are heavier than in conventional cars because EVs are equipped with heavy battery packs. Also, overall automobile weight has been on the rise as they are increasingly equipped with components for new advanced features, sensors are a key example of this. This makes weight reduction increasingly more important.
Q. Do you think lightweight technology has the same level of importance as other mobility products?
There are many types of future mobility solutions ranging from automobiles, ships and air transport solutions which are currently referred to as Personal Air Vehicles (PAVs). They are all expected to be completely electrified and to no longer be run by internal combustion engines. This means all of them will be equipped with large battery packs and could benefit from lightweight technology, giving them a longer range. Therefore, electrification is likely to create a greater demand for lightweight technology.
Q. What are the types of lightweight technologies employed in Hyundai – Kia vehicles?
First, we are making plastic parts as light as possible. We are making them thinner and with less plastic in the materials mix, achieving weight reduction while preserving the design specifications, whilst key requirements such as strength and reliability are still achieved. Also, many plastic fiber reinforcements such as inorganic materials and fillers are applied to plastics. Low-weight plastic materials are used for bulky exterior parts such as bumper covers and side seal moldings, and large interior parts such as crash pads.
Q. The word “carbon” comes to many when people think of lightweight materials. Is it currently employed by Hyundai or Kia?
The Kia STINGER comes with a carbon package as a part of the “Tuon” tuning options. It includes side mirror covers and a fender garnish for improved aesthetics. The limited edition version of Kia STINGER GTS also had a carbon package included and was well received in the market. Carbon package options for interior parts, bonnet, roof and so on will be made available for several models starting this year. The i30 N project C, which was unveiled at the Frankfurt Motor Show is the first example.
Q. Aren’t carbon fiber materials overly expensive for non-luxury brand models?
Carbon fiber parts are usually reserved for super cars and high performance models with six-figure prices. We were able to offer carbon fiber options for models priced around 40,000 USD thanks to the supply chain we completed earlier this year. More specifically, we were able to establish a domestic supply chain from raw materials to finished parts with a highly competitive cost structure, enabling our customers to enjoy high quality carbon fiber components at a reasonable price.
Q. How do parts made of carbon fiber materials perform in terms of safety?
If vehicle structure parts are made of carbon fibers, they are reinforced with aluminum parts for reinforcement to absorb impact. The same is true for side body parts made using carbon. Material characteristic-wise, carbon fibers are very sturdy even compared to steel materials in terms of passenger protection. If an impact was strong enough to break a vehicle body made of carbon, a steel vehicle body would have suffered the same amount of damage. Although carbon materials look like plastic, they are composite materials reinforced with fibers, making them more effective at absorbing impact energy than steel.
Q. Is there any other industry that employs composite materials such as carbon?
Carbon materials are widely employed in the wind power industry. The large blades for turbines are made with a combination of carbon and glass fibers to make them strong and light. A ship’s propeller on a large oil tanker is also made of lightweight composite materials to reduce engine load. Over 60% of materials used on airplanes are made of carbon materials by weight. The proportion is even higher for fighter jets for improved stealth capability.
Q. Is there any other promising composite materials beside carbon?
We are currently working on continuous fiber-reinforced thermoplastic, which is a composite material that contains high-performance continuous fiber that is impregnated where reinforcement is needed in a matrix of thermoplastics. The fibers become flexible when heated which makes it possible to use it with plastics during an injection molding process. It is possible to make high-strength lightweight components using plastics as the base material. The continuous fiber can withstand heavy loads and improve shock absorbing capacity. It is also less expensive compared to composites made with carbon fibers only. We plan to try using thermoplastic for some components which promises great performance at lower costs.
Q. Where do you think lightweight materials research for automobile and future mobility is headed?
We plan to create a database for materials characteristics fast and to strengthen our capacity for materials research. Our ability to tap into virtual simulation methods in materials research, which is employed in vehicle testing, is a unique strength. In the past, materials development relied on actual experiments: mixing two or more materials and testing their performance and properties. We expect to develop new lightweight materials in a more effective and speedy manner using the database and the simulation methods.