Finding the right formula

The University of Sheffield Mechanical Engineering Department are competing in Formula Student 2015, held at Silverstone this year. Among the challenges they faced was material selection for the braking system, which was overcome with help from Wallwork Cambridge.

Team Principal, Thomas Bloomfield said: "The competition exposes students to a raft of real-life engineering problems. A key design objective was to achieve good power to weight ratio for race advantage, so titanium alloy was selected for brake components, but this created a new technical challenge."

Nathaniel Wellicome, a final year student who led the chassis and vehicle dynamics team, explained: "Unfortunately, relative to heavier alternative materials such as steel alloys, titanium is a soft material, so it can bind when under load in metal-to-metal contact."

Dr Jonathan Housden, project leader at Wallwork, continued: "The parts were delivered to us with the mating surfaces machine cut to overcome the typical surface roughness that is common in 3D printing. This gave a smooth surface for the coating, but applying a hard coating to this machined surface on its own would be insufficient since the titanium substrate alone is too soft and the coating would break up under load.

"The answer was to use Nitron O, a duplex process that first infuses nitrogen compounds into the metal surface to produce a hard layer to support the subsequent titanium nitride surface coating. This permits the alloy to be used in high-load sliding wear applications, giving endurance and the required frictional properties, without binding."

Wallwork claim their Nitron O treatment is the first commercial duplex process for titanium alloys where the heat treatment and coating phases are administered in one single cycle within the same chamber. Normally the material of choice would be steel, however with Nitron O, Titanium alloys can be substituted providing comparable mechanical performance to Fe while weighing 50% less.

Silverstone will host around 100 international teams from leading UK and overseas universities for the race and technical judging between July 9 and 12. In addition to the race, a team of expert judges will score the cars on factors such as endurance, cost and sustainability.

Tom Austin-Morgan

This material is protected by MA Business copyright
See Terms and Conditions.
One-off usage is permitted but bulk copying is not.
For multiple copies contact the sales team.


Do you have any comments about this article?

Your comments/feedback may be edited prior to publishing. Not all entries will be published.
Please view our Terms and Conditions before leaving a comment.

© MA Business Ltd (a Mark Allen Group Company) 2021