Electronics Incorporated - The Shot Peener - Shot Peening Library
Title: Shot Peening of Ceramics: Damage or Benefit?
Author: Frey, Pfeiffer
Source: Conf Proc: ICSP-8 Sept. 16-20, 2002 Garmisch-Partenkirchen, Germany
Publication year 2002
Document number: 2002026
Number of pages: 6
Abstract:
Authors
Tobias Frey, Wulf Pfeiffer, Fraunhofer Institute for Mechanics of Materials, Freiburg, Germany
Abstract
Non-transformation toughened ceramics show the typical brittle material behavior of failure before deformation at room temperature. Thus, strengthening of ceramics due to
deformation induced compressive residual stresses has been thought to be not possible. Nevertheless, preliminary investigations had shown that, using ceramic-specific
parameters, shot peening can introduce high compressive residual stresses into the near-surface of silicon nitride and improve the load capacity. The aim of the presented
investigation was to improve the shot peening conditions in order to extend the increase of load capacity while maintaining the surface integrity. The materials investigated
where alumina and silicon nitride, the properties determined where residual stresses, load capacity and topography. For the assessment of the surface strengthening the X-Ray
diffraction analysis (XRD) and the ball-on-plate strength test were used. Due to the low penetration depth of X-rays XRD allows to evaluate the peening-induced residual
stresses. In the ball-on-plate test, the sample is loaded with a spherical silicon nitride indenter up to failure of the sample which is detected by a high frequency
ultrasonic detector. The results show that high compressive residual stresses in the GPa-range can be introduced in silicon nitride and alumina which may boost the load
capacity of the near surface layers by a factor of up to 9. Only little effect on the surface integrity could be obtained.
Download full text pdf file
www.shotpeener.com
This page last revised: 04/24/2008