Polycarbonate offers engineering flexibility in creating sleek curves and modern designs. It's impact-resistant properties improve vehicle safety. It is a light-weight material, reducing the weight of vehicle components by up to 50%. For example, sunroofs have increased in size, offering panoramic views. But, they are much lighter as a result of polycarbonate replacing glass. The weight reduction also reduces fuel consumption and CO2 emissions.
In addition to bumpers, plastics (polymer-based materials) are used in a variety of car lights, including headlights, fog lights, tail lights, signal lights, and back-up lights. In fact, plastics have all but replaced glass, becoming the dominant material for car lights. And, why not? Plastics are heat and shatter-resistant, capable of being moulded into almost any shape. This gives designers and engineers ultimate creativity in their styling and placement. Supported by oil prices and regulations, plastics are expected to shift from petroleum based to organic sources (bio-materials) in the future.
Bake Hardened Steel
Bake hardening is an advanced processing technique that produces low carbon steels with a higher strength than milder steel. Prone to impact, car doors are typically made of bake hardened steel.
High-strength low-alloy steel (HSLA) is a low carbon steel that provides better mechanical properties and greater resistance to corrosion than milder steel. Unlike other steels, HSLA is made to meet specific mechanical properties instead of a specific chemical composition. Various alloying elements are added to achieve these properties, HSLA steels are 20-30% lighter than a carbon steel with the same strength. They are also more resistant to rust than most carbon steels.
Where will you find HSLA? Look under the hood. HSLA steel is used in the engine cradle and motor compartment rail.
Dual Phase Steel
Dual Phase Steel (DP Steel) is a high-strength steel produced from low or medium carbon steel that are quenched. DP steels are ideal for automotive-related sheet forming operations.
Where will you find DP steel? It is used in bumpers, front fenders, and occasionally in wheels.
Hot Formed Steel
Rolling involves creating sheets of steel by using large rolls to reduce its thickness, similar to stretching dough with a rolling pin. Sheet steel can be eithr hot-rolled or cold-rolled. Hot formed steel (HF Steel) is heated above the recrystallization temperature. Cold rolling involves temperatures below the metal's recrystallization temperature. It results in a thinner product but the process is costlier. Due to its strength and durability, hot formed steel is used in chassis and wheel systems, in addition to the A-pillar.
Aluminum is used in hoods, bumpers, vehicles body frames, transmissions, engine parts, wheels, and foot pedals. When blended with stronger alloys, aluminum is remarkably strong yet very light. It is also malleable, offering engineering design flexibility while improving fuel efficiency for car owners. Aluminum alloys may even improve safety because vehicle parts can flex under impact, absorbing energy during a crash. Vehicle aerodynamics is also improved, translating to better acceleration, braking, and handling.
The need for lighter vehicle weights and better fuel efficiency will result in more aluminum components in the next 10-15 years.
Mild steel makes up a large portion (approximately 80%) of the vehicle. It contains less carbon (typically between 0.05 to 0.25%) than a higher carbon steel (0.30% to 2.0%). This makes it more ductile, machinable, and weldable than higher carbon steels. However, it has less tensile strength than high carbon and alloy steels. And, it is subject to oxidation (rust) if not properly coated.
Not as strong and prone to rusting... why is mild steel used so extensively in cars? Perhaps because it is relatively affordable since it does not contain alloys.