Evaluating the Homogeneity of Surface Features Induced by Impact-Based Surface Treatments

Abstract

Impact surface treatments are well-known for their efficiency in enhancing the mechanical properties of metallic materials, especially under cyclic loadings. These processes, which encompass a wide range of surface treatments based on repetitive impacts of tools of various types, induce surface plastic deformation, compressive residual stresses, and grain refinement alter the surface roughness as a side effect. Thus, it is essential to have suitable indexes to quantify the surface features caused by the typically random nature of these treatments. Herein, we evaluated the rationality of using standard roughness parameters for describing the morphological characteristics of surfaces treated by shot peening as a representative and widely used treatment of the category. A detailed numerical model of the peening process was developed. The output data were elaborated to extract the surface roughness parameters following the standard procedures. The results revealed the validity of the surface roughness parameters to describe the topography of material treated with adequate surface coverage, also highlighting the necessity to use a set of parameters rather than the common practice of relying on single parameters. Not considering a comprehensive set of amplitude and spacing parameters can result in significant, inconsistent, and misleading results while comparing the performance of surfaces.

Adapting Shot Peening for Surface Texturing Using Customized Additive Manufactured Shots

“…It was shown for Armco iron that regardless of an inherent variation in the roughness parameters (such as Sa, Sq), due to random peening in terms of impact positions using spherical shots, the saturation occurred at coverage levels higher than 50%, with even a decrease in the parameters within the coverage range of 50–100%. [ 27 ] Comparable behavior was detected in this study for the evolution of roughness parameters upon peening ABS polymer using custom‐made shots.…”

“…The details of the code can be found in the author's previous study on classically shot peened surfaces. [ 27 ] The evolution of the roughness parameters as a function of impact number (directly related to peening coverage) at two different shot impact velocities is shown in Figure . The roughness evolution at high surface coverage levels with an impact velocity of 10 and 5 m s −1 (starting from the 30th and 24th impacts) is shown in Figure 6a,b, respectively.…”

Effect of ultrasonic rolling on the surface integrity and corrosion properties of GCr15 steel before and after quenching

“…Traditional surface strengthening techniques like shot peening [3,4], surface carburizing and nitriding have improved the surface properties of materials to some extent. But high roughness and severe deformation and stress concentration persist after shot peening [5,6]. Surface carburizing and nitriding treatment have disadvantages of the shallow compressive stress layer and high surface brittleness [7], which cannot efficiently improve the fatigue life of the material.…”