Titanium springs for vehicle lightweighting

To reduce weight, conserve energy, and optimize space, lowering component weight is a priority for most motor vehicle manufacturers and their suppliers. Spring designs can comply with today's trends for smaller, lighter products, while still delivering optimum performance. Substituting titanium alloy springs for more conventional steel springs provides many advantages in weight, size, and performance, but also calls attention to some important considerations.

Titanium advantages

Steel alloys are the most common spring manufacturing materials. However, when it comes to lightweighting, titanium springs are up to 70% lighter. Titanium is less dense and has an approximately 2x lower shear modulus than steel, making it twice as springy. Spring deflection is also higher, meaning titanium spring designs require fewer active coils than comparable steel units. Designers can also reduce spring free-height, saving space and weight without sacrificing performance.

With lower weight and density, titanium springs require less energy to accelerate and decelerate when the spring moves. Lower mass and energy requirements reduce spring surge, resulting in smoother, more-controlled motion under load.

Springs made with larger wire diameter but fewer coils provide a spring rate equivalent to that of the steel spring being swapped-out.

Add titanium's high corrosion resistance, and the material becomes attractive for applications where weight and space are critical, especially in harsh environments.

Titanium limitations

Titanium is only about 75% as strong as steel. For heavy-duty applications, engineers can compensate, to some degree, by increasing the wire diameter of springs. The metal’s long-term wear-resistance is also not as high as steel, but methods such as anodizing increased surface durability.

The biggest drawback is cost. Traditionally, titanium costs 6x or 7x more than steel.

The good news for titanium is that today's manufacturing research is rendering ways to produce titanium wire more cost-effectively. New alloys, specific manufacturing techniques, and increases in overall production rate of titanium are steadily driving down cost.

Determining if titanium springs make sense requires a cost-benefit analysis of each application. For example, if a lightweighting program for a commercial truck employs titanium springs, and those springs lower weight and reduce vehicle operating cost, then the price premium for the lightweight material may be offset or negated.

Spring expertise

Titanium is a premium alloy worthy of consideration in various applications where size, weight, and performance are critical. Leading spring manufacturers, such as Newcomb Spring Corp., can manufacture custom springs from a variety of lightweight premium alloys, as well as offer expertise and assistance in specifying high-performance metals for specific spring designs and applications.

Newcomb Spring Corp.
www.newcombspring.com