Chevrolet is going to debut a brand new lightweight “Smart Material” on the Corvette model. In particular this is a heat-activated shape memory alloy which is going to replace heavier motorized parts.
Since its first appearance in 1953, the Corvette has a six-decade track record for introducing lightweight materials that improve cars performance. Now, the trend is continued, with the new 2014 Chevrolet Corvette Stingray weighing in 99 pounds lighter than its predecessor.
The latter model is the first vehicle to use the “smart material” – lightweight shape memory alloy wire in place of a heavier motorized actuator to open and close the hatch vent that releases air from the trunk. This allows the trunk lid to close more easily.
But, what exactly are the shape memory alloys? They are usually made of copper-aluminum-nickel or nickel-titanium and can change their shape, strength, and/or stiffness when activated by heat, stress, a magnetic field or electrical voltage. Shape memory alloys “remember” their original shape and return to it when de-activated.
In the latest seventh generation Corvette, a shape memory alloy wire opens the hatch vent whenever the deck lid is opened. It utilizes heat from an electrical current in a similar manner to the trunk lights.
When it is activated the lever arm is moved and opens the vent, allowing the trunk lid to close. When the latter is closed, the electrical current switches off. This allows he wire to cool and return to its normal shape. Unwanted mass is also removed by shape memory alloy. This of course enhances performance and fuel economy.