Our surface treatment expertise


Reinforce your simple or complex geometry metal parts using our ultrasonic activated shot peening process (standard and customized machines, shot peening and conventional sanding accessories, outsourcing service). Learn more

  • Ultrasonic shot peening - work hardening and cold working process
    What is shot peening ?
  • Ex-situ Subcontract shot peening - SONATS
    Shot peening equipment
  • Automated shot peening equipment
  • Shot peening service


Modify the geometry of your sheets and metal parts using our portable ultrasonic needle peening and peen forming system. This system is easy to set-up and use as well as being approved by many prime contractors. Learn more

  • Aerospace peen forming equipment
    STRESSVOYAGER® UNS* - Portable ultrasonic shot peen forming equipment for aerospace SONATS has developed a portable, compact and lightweight equipment: the STRESSVOYAGER® UNS*. This equipment is ideal for improving the productivity of your factories by allowing straightening or forming directly on the jig. This equipment is particularly used in the aerospace industry for forming wing and fuselage panels. Moreover, thanks to the optimised design of the treatment head, its accessibility and its portability, the STRESSVOYAGER® UNS can be used to straighten complex geometry parts, with or without stiffeners, and of varying thickness (from 4 to 60mm). The portable equipment allows to precisely adjust the shape of the metal parts during the controls-measurements which are particularly important for the aeronautical industry. Download our dedicated brochure on our handheld equipment - STRESSVOYAGER® - Peen forming ultrasonic system   Download REDUCTION OF MUSCULOSKELETAL DISORDER RISKS The STRESSVOYAGER® UNS facilitates efficient and safe operations for both the operator and the work piece. Straightening and forming operations are very fast and yet the vibrations of the treatment head are very weak, and there is no transfer of vibrations to the operator. Ultrasonic straightening operations will greatly reduce musculoskeletal disorders (MSDs) compared to conventional impact methods such as boiler making. Moreover, set-up by the operator is much improved by a simplified touch human-machine interface and a plug and play system. *Ultrasonic Needle Straightening/Shot Peen Forming STRESSVOYAGER® UNS - Ultrasonic shot peen forming equipment on mobile carriage Close Examples of applications using our portable ultrasonic needle straightening and shot peen forming equipment in the aerospace industry Forming a complex geometry aeronautical part For optimum processing of a complex geometry stiffeners, the STRESSVOYAGER® UNS was equipped with an angled treatment head with an angle of up to 30°. There are other types of treatment heads and interchangeable end pieces (peening head) depending on the intensity and accessibility conditions. Machined parts forming operation Following machining, particularly at the edge of its pockets, the frame was significantly deformed. To improve access to the areas to be treated, a specific treatment head was developed by SONATS. In the case of an aero-structure piece machined in a hard material such as a titanium alloy, the treatment head may be equipped with a specific end-piece (width of the end-piece, number and diameter of the impactors) for better efficiency. Peen forming/needle straightening a stiffener directly oh the final part The straightening/forming action on the stiffener achieves the final shape and its adjustment directly on the final part. (photo above: before straightening/photo below: after straightening Forming operation at one of our customer's premises Use of STRESSVOYAGER® UNS equipment by Airbus to finalise the shape of the work piece after forming. The operator measures the deformation and carries out the straightening operation until the desired final shape is achieved. SPECIFICATIONS - REFERENCES Our forming technique has been used for many years by the main prime contractors and equipment manufacturers of the military and commercial aeronautic sector. Our process has obtained qualifications and is described by dedicated internal specifications: SAE/AMS 2588 Ultrasonically Activated Needle Peen Forming AIRBUS AIPI 03-10-001 Rectification of metallic materials by shot peening AIRBUS AIPS 03-10-001 Hard Metal Forming - General Requirements DASSAULT DGQT 4 2 0152 Mechanically machined aluminium alloy part finish DASSAULT DGQT0 8 3 0181 Ultrasonically activated forming ©AIRBUS SAS 2016 – Tous droits réservés / All rights reserved
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  • FShot peen forming aerospace - SONATS
    Peen forming
    Peen forming process Mechanical needle peening and peen forming operations generally means finishing the shape of a component or a metal structure. Following large deformations, these straightening or forming operations can be performed using a high-load press to exert mechanical pressure. For finishing, or where deformation occurs after chemical or mechanical treatment, the most common way to precisely adjust the curvature of a work piece is to use a simple boilermaker hammer. The use of the hammer involves a significant treatment time and can cause musculoskeletal disorders to the operator. A pneumatic hammer may also be used. PRINCIPLE OF THE ULTRASONIC PEEN FORMING OR NEEDLE PEENING PROCESS Our cold impact mechanical treatment process is a reliable and proven alternative to a hammer or pneumatic hammer, with less impact on operator health. With efficient process control combined with quick and easy tooling, this solution is increasingly becoming popular throughout the industry. The forming and straightening operation changes the geometry of a metal piece to progressively reach the desired shape. This mechanical peen forming and needle peening process uses STRESSONIC® technology. The impactors located in the treatment head pick up velocity in contact with the vibrating sonotrode and impact the metal to be treated. They act like a network of tiny hammers striking the surface at high frequency, and independently of each other. This creates superficial compressive stresses. The difference in stress between the surface and the core of the metal plate causes a change in the plate curvature. By treating the appropriate surface, it is possible to adjust the shape of the part to the specified geometry. The shot peen forming treatment is applied on the part with our portable peen forming equipment : STRESSVOYAGER®. STANDARDS AND SPECIFICATIONS SAE/AMS 2588 Ultrasonically activated Needle Peen Forming AIRBUS AIPI 03-10-001 Rectification of metal materials by shot peening AIPS 03-10-011 Hard Metal Forming - General Requirements DASSAULT DGQT 4 2 0152 Finishing of mechanically machined aluminium alloy parts DASSAULT DGQT0 8 3 0181 Ultrasonic activated shaping Download our dedicated brochure on peening forming process Download Learn more information on our equipment to apply shot peen forming / needle peening treatment on your metal parts ! Portable ultrasonic shot peen forming equipment Progressive effect of the ultrasonic mechanical peen forming process on an aluminium part Ultrasonic needle peening - mechanical peen forming treatment peening head end-piece SCIENTIFIC AND TECHNICAL PUBLICATIONS - Read our publications about ultrasonic shot peen forming and straightening process. Photo header © AIRBUS SAS 2016 – Tous droits réservés / All rights reserved
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Improve the fatigue resistance of welded assemblies by modifying the geometry of the weld toe with our ultrasonic impact treatment process, an embedded process on a portable or automated equipment. Learn more

  • Parachèvement de soudure par ultrasons - SONATS
    Ultrasonic impact treatment
    Ultrasonic weld impact treatment - HFMI/UIT Improved fatigue resistance HFMI (High Frequency Mechanical Impact), also known as UIT (Ultrasonic Impact Treatment), is a high-frequency weld impact treatment designed to improve the fatigue resistance of welded structures. It is a cold mechanical treatment that involves striking the weld toe with a needle (or striker) to create an enlargement of its radius and to introduce residual compressive stresses. The new recommendation published by the IIW proposes a gain of 4 to 8 fatigue classes depending on the yield strength of the treated steels. The improvements actually noted in the study with our equipment show even more significant improvements. To know more about our ultrasonic impact treatment, download our flyer, section ultrasonic impact treatment I download! Principle of ultrasonic weld impact treatment Improvement of the lifetime of a part after ultrasonic weld impact treatment Increase in stress corrosion cracking (SCC) resistance The creation of superficial compression, by peening, due to the impact of the needles on the material also makes it possible to improve the resistance for stress corrosion cracking. As this phenomenon occurs on structures and assemblies exposed to corrosive environments, the HFMI/UIT process helps to delay or even eliminate the appearance of cracks. Correction of distorsions due to welding The stresses created by welding processes cause distortions in the welds between the panels. These well-known distortions occur during the cooling phase of the weld, when the molten metal shrinks, resulting in plastic deformation of the welded metals. In order to eliminate tensile stress, conventional stress relieving processes are currently applied locally (heating, TIG dressing, etc.). These processes restore a stress level close to 0 MPa at the surface and at a depth but do not correct the defect created by the weld. Correction of distortions due to welding Close Browse the tabs below to explore in detail the objective, applications, studies and recommendations of ultrasonic impact treatment. ObjectiveApplicationsStudies and recommendationsObjective Objective - Ultrasonic impact treatment The ultrasonic impact treatment (HFMI / UIT) process not only allows to create residual compressive stresses, which are much more beneficial than stress relief but also allows to straighten the deformations caused by welding. The 2 in 1 effect of ultrasonic impact treatment (HFMI / UIT) is particularly valuable when the aim is to improve the fatigue strength of steels, aluminium and other metal alloys while correcting geometrical defects. Why should I use it? To increase the fatigue life To increase the fatigue limit To reduce the weight To reduce or compensate the distortions induced by the welding When should I use it? 1In the design calculations 2On new parts production 3For maintenance and repair 4To extend the fatigue life of service parts Applications Fatigue resistance technologies, such as NOMAD (ultrasonic weld impact treatment equipment), are regularly and successfully used in many sectors: aerospace, energy, automotive, defence, transportation and infrastructure. Agricultural machinery Handling and transport Industrial equipments Infrastructures Naval / Marine Power Generation When producing a part or making and assembling a structure, the first step in controlling fatigue resistance is to assess the most critical areas where cracks may appear. Then the best process to apply must be determined. The key to this choice is to assess whether a method of improving fatigue resistance is needed before the onset of major damage. A preventative rather than a corrective approach is much better in order to minimise costs and maximise profits. Ultrasonic impact treatment is one of the best preventive treatments to improve the fatigue resistance of welded structures. Studies and recommendations The effectiveness of the process has been demonstrated in numerous international research studies. Do you notice cracks on your mechanically welded parts and sub-assemblies? The characterisation of your materials and the measurement of residual stresses after welding will enable you to improve the design of your parts and your welding processes. Download the brochure of our laboratory dedicated to residual stress and material characterisation.  I Download!
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  • Opération manuelle de parachèvement de soudure - SONATS
    Ultrasonic impact treatment equipment
    NOMAD - Portable ultrasonic impact treatment equipment Our NOMAD equipment is designed and built to guaranty weld impact treatment requirements and needs on site but also in the production workshop. Its strong design, protected by a transport wheelcase and its STRESSONIC® ultrasonic technology ensure easy access to the areas to be treated combined with an optimal quality of treatment. Our lightweight and portable NOMAD HFMI/UIT equipment is used directly on-site for the treatment of your welded structures (examples: road or rail infrastructure, heavy machinery). This solution reduces: the resources required for treatment, the infrastructure downtime and the maintenance costs. Our equipment is designed to be strong enough to withstand outdoor use. Moreover, our international network, our reliability and our responsiveness mean that we can offer you quality services anywhere in the world. Download our dedicated flyer to discover NOMAD's advantages and accessories Download ! SONATS provides distance learning of our ultrasonic impact treamtment equipment NOMAD. From equipment presentation to first level maintenance. Get safely trained ! Contact-us for more information. Weld impact treatment applications Convex welding Heat affected area Flat and concave welding Examples of portable ultrasonic weld impact treatment equipment applications STRENGTHENING DEFENCE VEHICLES For defence vehicles such as forward crossing vehicles need require optimum quality of the welds and the structure is vital. This is why the NOMAD portable device equipped with specific end-pieces (standard and multi-impact) was used for preventive treatment of weld impact treatments and peening of flat surfaces. The aim is to improve resistance to stress corrosion cracking for aluminium alloy defence vehicles. ROAD INFRASTRUCTURES REPAIRS Faced with the increase of traffic and the increase of the transported loads, mechanically welded assemblies of road infrastructures are subjected to considerable tensile stresses. SONATS supplied the NOMAD portable device for curative treatment of platforms on welded steel metal bridges, aiming to repair and improve the lifetime of welds. NOMAD was also been used on new bridges in the USA, Canada, Europe and Asia for crack prevention treatment. REPAIR OF MARINE STRUCTURES Marine structures are subject to cyclic stress due to variable loading and the aggressive environment. Equipped with a NOMAD fitted with an angled end-piece for hard-to-reach areas, operators applied a curative peening treatment to an aluminium patrol boat that had suffered corrosive and mechanical damage. RAILWAY TRACK REPAIRS The frequency of trains and their associated weight are very variable and subject the railway tracks to high compression which cracks the welds of the rails at certain junction points. The railway company worked with SONATS to develop a new repair procedure with the NOMAD portable equipment, equipped with a treatment head specifically designed for the work and an inclined end-piece for treatment in the field to access difficult to reach areas. Learn more about our range of customized accessories and peening head
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  • Ultrasonic impact treatment services
    Ultrasonic impact treatment services With more than 20 years of experience in ultrasonic surface impact treatments for the improvement of fatigue performance, SONATS proposes weld impact treatment services for your welded structures. Thanks to the simplicity of our portable equipment, SONATS can send a team of technicians to your site within one to three weeks whether it be in France or around the world. SONATS performs preventive treatment where fatigue cracks have initiated or curative treatment where there is propagation of cracks. SONATS is also open to partnerships with companies wishing to offer such services using our portable ultrasonic weld impact treatment system, the NOMAD. Download our white paper on ultrasonic needle peening Download Examples of ultrasonic impact treatment services (HFMI-UIT) on customer sites PREVENTIVE TREATMENT FOLLOWING THE DISCOVERY OF FATIGUE CRACK INITIATION Following a study commissioned by the port authority of DOVER, the consulting firm warned about crack initiation. After analysis, it was decided to apply a high-frequency mechanical impact treatment (HFMI-UIT) on all critical areas of each bridge to avoid the spread of cracks (about 4km of weld toe). Two devices were rented for 1 month, for use 7 days a week and 10 hours a day. This solution was used to extend the fatigue lifetime by at least two times that of the initial life cycle before HFMI. PEENING OF ROAD INFRASTRUCTURES Cracks on the weld toe of the upper deck of the George Washington Bridge (NY) were observed. A preventive and curative treatment was then applied by the American Bridge team over a period of one year using 4 devices. The cracking preventive treatment on the weld bead of the zones concerned made it possible to extend the fatigue lifetime of the bridge. TREATMENT OF CIRCUMFERENTIAL WELDING ON A HEAVY PLANT FRONT LOADER To increase the fatigue lifetime of a circumferential weld of a front loader lift arm, SONATS technicians, equipped with two NOMAD devices, went to the customer site to apply a preventive treatment on all welds. This treatment made it possible to increase the number of lifting cycles from 200,000 to 5 billion TREATMENT OF AN ALUMINUM SUPER STRUCTURE OF A WAR VESSEL Several categories of US Navy vessels were built with a 5XXX series aluminium chosen for its mechanical properties (AA5456 and AA5083). However, high temperatures and the saline environment sensitise the surface and cause cracking due to stress corrosion. SONATS technicians, equipped with our portable NOMAD system, intervened on several vessels to apply an impact treatment to weld toes in critical areas.  The ultrasonic impact treatment process is approved by the US Navy. Scientific and technical publications Read technical and scientific publications discussing about ultrasonic weld impact treatment such as our white paper (Fatigue life improvement of welded structures by ultrasonic needle peening) gathering SONATS' experiences.
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The stress and materials characterisation laboratory provides services including measurement and analysis at the laboratory itself but also at your production site when needed. Learn more

  • Contour method - residual stress measurement - SONATS
    Contour method for residual stress measurements
  • Eddy current testing for residual stress measurements
  • hole drilling method -residual stresses - SONATS
    Hole drilling for residual stress measurement
  • Metallurgical testing
  • Residual stress measurement
  • Ring core method residual stress measurement
    Ring Core Method
  • Surface and dimensional metrology
  • X-ray diffraction services

Our history

For more than 25 years, SONATS has been providing impact surface treatment solutions and laboratory services :

SONATS is an innovative industrial company specialised in cold impact mechanical surface treatment, the main process being ultrasonic shot peening (STRESSONIC® Technology).

Based on its specialist knowledge, SONATS designs and manufactures a complete range of products, from portable equipment to customized machines, as well as providing training, outsourcing and residual stresses analysis services, both on and off site.

Renowned, qualified and certified, SONATS is committed to providing the best technology via our dedication to R&D to perfectly fulfil the continuously evolving needs of our customers.

Our customers

News & Events

Read our latest news, dates of participation to regional and international shows, articles and job advertisement. 

International conference on residual stresses – ICRS11

The 11th international conference on Residual Stresses will take a place in Nancy from march 28 to 30, 2022. The conference will be punctuated by breaks during which you will…

[WEBINAR] Shot peening innovations for high-performance transmission parts

Watch the replay I would like to be recalled to discuss about my project.I want more information. I download flyers in the shot peening section. Join this webinar to find…

Ultrasonic Shot Peening vs Conventionnel Shot Peening – The importance of key parameters

SONATS’ expert demonstrated in a study that STRESSONIC® Ultrasonic Shot Peening (USP) process could replicate Conventional Shot Peening (CSP) process. Amongst this study they have been able to highlight that…