Generic Almen Fixtures for Intensity Measurement in Shot Peening

Author:  David Pacciolla
Source:  The Shot Peener magazine, Vol 22 / Issue 1, Winter 2008
Doc ID:  2008003
Year of Publication:  2008
Abstract:  
Applying the shot peening process on aerospace parts can be a tough challenge as geometries can get complicated and requirements quite strict. Documented cases of aerospace component failures also remind us of the value of all processes involved in the production of a part, as every operation is important in order to achieve expected mechanical properties. In order to be as precise and flexible as possible, the use of CNC or robotic machines is often the logical way to deal with a wide variety of parts, complicated geometries and short turn-around times. As specifications are also evolving with more precise requirements in terms of intensity and coverage control, the new generations of CNC and robotic shot peening machines are often the only option that will allow meeting those requirements. However, when working with CNC machines, it doesn't take long to recognize that many current specifications were first issued when the only available methods for shot peening were manual, centrifugal wheels and simple automated nozzle machines. Requirements like the eight hours interval between intensity verifications and media analysis remind us that the new generations of precise and highly controlled machines were not available a few years ago. As specifications are evolving, it can be interesting to make them more applicable to CNC or robotic gun manipulator machines while enhancing control and quality.