Titanium Coil Springs for Automotive Suspension Systems

Titanium is a strong, lightweight metal which is used extensively in aerospace applications. By virtue of these properties plus low elastic moduli it is particularly suitable as a spring material. Compared to steel springs of equivalent performance, titanium springs weigh less than half as much and can be designed to be more compact. The current need to reduce vehicle weight to improve fuel economy has led to a prototype development program to assess the weight saving potential of suspension springs. Front suspension springs made of β-titanium alloy were designed, fabricated and tested. The results indicate that such springs could serve as direct replacements for steel springs with a weight saving of 53%, while satisfying fatigue life, spring rate and design load requirements. Suggestions for improvements in the processing of the spring wire and fabrication have been identified which could result in even greater weight saving and lower cost. While these results demonstrate attractive advantages offered by Titanium springs, vehicle durability tests and manufacturing feasibility studies are needed to more fully assess their costs and benefits.