14th International Conference on Shot Peening

Controlling Surface Roughness Through Shot Media Size Distribution

David Bahr, Siavash Ghanbari

School of Materials Engineering, Purdue University, West Lafayette IN 47907

dfbahr@purdue.edu

Introduction

Controlling the compressive residual stresses and surface roughness parameters can maximize a shot peened metallic components’ lifetime, there should be interaction between. Shot peening changes a surface’s surface roughness, and is impacted by peening media size and/or time. As a result, the surface condition impacts the overall mechanical reliability, in many cases with rougher surfaces leading to decreases in lifetime. However, in some cases rougher surfaces may be desired, such as applications tied to lubrication and stick/slip contact. Dual peening has been demonstrated to provide a smoother surface while maintaining deep compressive stresses, but requires multiple processing passes.

Objectives

The goal of this study was to develop a predictive simulation tool, which could be validated, to explore the ability to control surface roughness in conjunction with residual stresses. By controlling the distribution of shot sizes, we aim to demonstrate it is possible to provide a smoother surface than would be created by large diameter shot, but yet still achieve a deep compressive stress profile similar to a larger shot diameter in a single shot peening passage.