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 the USP process is more advantageous than CSP process regarding the good repeatability and controlled of the process.
Particularly for maintenance, repair and overhaul (MRO), the control of media provides the capability to complete repairs located in areas with complex geometry or on parts too large to fit into a Conventional Shot Peening (CSP) booth. This will provide a shot peening capability at or near the field location that could significantly reduce aircraft downtime, reduce supply and distribution requirements, decrease stock forecast, and increase flight readiness.
And for both, MRO and lean manufacturing production the control of the amplitude of the vibration of the sonotrode allows to inscrease productivity by reducing the shot peening cycle time and the risk of human error via real-time control of parameters.
“Following the SAE AMS 2580* & SAE AMS 2585**, the amplitude of vibration is controlled in real time.
The tolerance is +/- 4µm/pv.
AMS 2580A
Table 1 – Parameters for ultrasonically activiated shot peening
| Paragraph | Parameter | Units | Process Tolerance Plus or Minus |
|---|---|---|---|
| 3.2.3.1 | Sonotrode vibration amplitude | Inch (millimeter) | 0.00016 (0.004) |
Figure.32. AMS 2580 specification
The result on Almen Intyensity is less than +/-1.8mmA compared to the AMS Standard +/-3.8mmA
Table 1. Effect of amplitude
| Amplitude (µm/pv) | Intensity (A) | Intensity (FA) |
|---|---|---|
| 60 | 8.3 | 21.1 |
| 65 | 9 | 22.9 |
| 70 | 9.7 | 24.6 |
| 75 | 10.4 | 26.4 |
| 80 | 10.9 | 27.7 |
On USP, the quantity of the media inside the tooling could also affected the result on Almen Intensity. But the effect is really low. This test was made with the following conditions : direction shot peening, 70µm of amplitude.
Table 2. Effect of amount of media
| %Lost | Mass (g) | Approx #Beads | Intensity (A) | Intensity (FA) |
|---|---|---|---|---|
| 0% | 4.6 | 460 | 9.7 | 24.6 |
| -5% | 4.37 | 437 | 9.7 | 24.6 |
| -10% | 4.14 | 414 | 9.8 | 24.9 |
| -20% | 3.68 | 368 | 9.9 | 25.1 |
Remark : The treatment time must be adjusted following the coverage required by the customer.”
Ultrasonic Shot Peeing, SONATS, 12/09/2019, p17
*SAE/AME – AMS 2580 Shot peening, ultrasonically activated
**SAE/AME – AMS 2585 Shot Peening media – ultrasonically activated
