Axiom was called in by Shoreham-based Ricardo Engineering, one of the world’s leading automotive consultancies, which was working on behalf of a major car company. The unnamed car company had appointed Ricardo to discover why crankshafts were failing in one of its engine families.
The problem was traced to minute cracks in the crankshaft journals and Axiom was tasked with determining the cause. Metallurgist Dr Rene Hoyle, who founded Axiom with fellow engineer Adam Potter in 2003, explained: “The design and production of automotive components is driven by the need for low cost, low weight and better efficiency.
“Designs which use higher strength materials, smaller diameters/sizes and lighter weight deliver lower frictional losses, greater efficiency, smoother running and lower operational costs. However, such developments don’t come without their own issues.”
He added: “Higher strength materials tend to be more notch-sensitive and more susceptible to fatigue cracking issues.In the case of crankshafts, the change of section at the edges of journals are a prime site for fatigue to initiate.”
Axiom sectioned the broken crankshafts so it could examine the actual machined radius profiles of the journals, which can be a factor in the initiation of fatigue issues.
Dr Hoyle said: “Manufacturers go to great lengths to make sure their latest designs are suitable for the intended application, but if things go wrong and cracking is found, they need to understand what is causing the problem.
“Axiom is ideally positioned to investigate the defects, categorise the cracks and determine whether they are due to overstress, fatigue, a manufacturing defect, material deficiency or something else.”
As a result of Axiom’s analysis the problem was pinpointed and changes made to the manufacturing process.
