VOL. 2 June ISSUE YEAR 2001


in Vol. 2 - June Issue - Year 2001
STRESSONIC, the Shot Peening of the next Millennium

Since 1997, SONATS, a French company, has been working closely with SNECMA to develop the first specific industrial Shot Peening machine based on the STRESSONIC(r) process. The target of this new surface treatment is to increase the resistance to fatigue failures of the mechanical parts under high solicitations.

The principle of this process patented by the French company is to make a small quantity of  high grade metallic shots vibrate thanks to ultrasonic waves. The shots strike the surface of the part exactly where it has to be treated. This innovative surface treatment associated with very precise measurement and testing technologies (residual stresses measurement by x-ray diffraction and prevention and detection of grinding burns by Barkhausen effect) allow SONATS to offer a full set of services: diagnosis, treatment and testing  of industrial parts on site or in our workshops. At the end of April 1999 the first ultrasonic shot-peening machine was delivered to SNECMA in order to treat fully automatically 3 parts of an aircraft engine.
In the field of surface treatment SONATS is the only company to master this original ultrasonic shot peening. The company develops and manufactures specific shot peening machines which can easily be integrated in production line. The company also does shot peening subcontracting in its workshops. Thanks to a portable shot peening equipment SONATS can also do quick and adapted field-jobs all around the world on massive parts which cannot be dismantled like in nuclear plants or in cement works.

This new shot peening technology machine developed for the customer is made of the following elements: a rotary arm to turn the part in order to treat both sides, three housings adapted to each part, an acoustic booster and an automaton. The automaton drives the whole motions of the different components of the machine as well as the ultrasonic treatment. The shots that come and strike the surface to treat have been carefully chosen (adapted hardness and perfect sphericity). The quantity of shots has been defined according to criteria of surface conditions, roughness and residual stresses profile.
The quantity of shots that treat the parts is steady in order to ensure a perfect repeatability of the treatment. All the parameters are set and controlled by an automaton which must stop the machine if there is a process drift or disorder. Only a few minutes are necessary to complete a full treatment cycle for one part.

STRESSONIC(r) Shot Peening Machine
The floor area of an ultrasonic shot peening machine is smaller than that of a conventional shot peening machine. The floor area of the machine delivered to the customer is 2,2 m2. Its height is 1,3 m and its weight 1 ton. A single phase 220 V and compressed air are requested to implement the machine. Since the balls are confined in a housing, the environment doesn't need to be protected.
The ultrasonic shot peening machine can be perfectly integrated to the production line. In comparison with the conventional shot peening, the production cycle is shorter and the production control is simplified. This technology is a clean shot peening and can be therefore used in specific field such as nuclear plants. Because of the compactness and the easy implementation of the machines as well as the perfect repeatability of the treatment STRESSONIC(r) is the shot peening technology of the future.

For Information:
Sonats (France)
Tel.: +33 251 700 494
Fax: +33 251 700 583
e-mail: sonats@sonats.com