By Alain Portebois
Sales & Marketing Manager, Charleville Technology Centre, Wheelabrator
While airblast peening has been widely and successfully applied for decades in Aerospace for improving or restoring the fatigue resistance of all critical components such as jet engine parts, landing gears and aircraft structures, nowadays the highest automotive standards are involving more and more the same level of technology.
Traditionally, many shot peening requirements in the automotive industry were covered by wheelblast technology. However, in the 1980s, demand started to change. Driven by the need to reduce component size (and weight) while maintaining its mechanical strength, shot peening processes became more and more precise. They had to be designed to induce compressive stresses to a narrowly defined pattern, enabling engineers to reduce material and strategically strengthen specific areas of a part.
This trend presented us here in Charleville with an opportunity to demonstrate the superiority of airblast technology for high-precision applications to automotive customers. Using our expertise from the aerospace industry, we developed a range of airblast machines to meet automotive industry requirements: to construct engines that are more powerful yet consume less petrol, and transmission components that are lighter yet outperform their heavier predecessors.
Since the 1990s, we have been servicing most of the big car manufacturers and suppliers. Just to illustrate the change: one big car manufacturer had no airblast at all in 1994 and now has 50 machines from us worldwide. Another customer vehemently preferred wheelblast in 1990 and now also has 50 machines.
That’s not to say that wheelblast as a technology is no longer present in Automotive. Many components, especially those with straightforward geometries and surface specifications, can be shot peened faster and more cost-efficiently using wheelblast. This is an area looked after by our colleagues at Technology Centres in Germany, Switzerland, Canada, China and India (some of these Centres also provide airblast equipment, specialising in a variety of industry/applications). Together, we cover all aspects of surface technology required by the automotive industries.
Mass production as R&D booster
The introduction of airblast in Automotive has, in turn, created a challenge for equipment manufacturers to develop processes that keep pace with the fast-moving, highly efficient mass production world of car manufacturing.
An example of how shot peening applications develop along with automotive manufacturing requirements is the case of dual peening. It’s not a new development, the technology has been around for about 15 years, but interest is increasing as it becomes more widely available.
Dual peening means using two different types of blast media in the same machine with a singleof blast nozzles. Bigger media induces stresses more deeply into the material, smaller media embeds residual compressive stresses in the immediate and medium surface. This allows us to play with blast parameters and design tailor-made blast processes for the customer, all in a comparatively compact machine, that fits in with lean automotive production lines.
Automotive shot peening around the world
The triumphal march of airblast in Automotive is not all-encompassing. China and India are big automotive manufacturers nowadays, bigger than Europe and America, but only vehicles built to the highest standards need shot peened components.
Across large parts of the BRIC world and beyond, the high speeds and performance that have pushed the boundaries of automotive engineering are becoming more and more popular, and therefore applying the airblast peening techniques is also becoming a must.
Since all shot peening projects are being deeply analysed by the end users, airblast equipment has the advantage of being compact, clean, and usually easy to integrate into the manufacturing line or robotic system. That’s why we’ll keep developing at the forefront of airblast technology, anticipating new materials and requirements, enabling engineers to build ever lighter, better cars.