Our preliminary experimental data, based on qualitative hardness testing, has shown that rotary and vibratory tumbling may result in a deeper hardening than previously understood. Further study may yield surprises with regard to hardness, hardness penetration, wear resistance and media interaction with various alloys. This study will analyze the effects of studio- and production-level burnishing on hardness, depth of hardness, and abrasive wear resistance on at least four common alloys. We will utilize macro- and micro-hardness testing of samples to determine depth of hardness and surface hardness. In an effort to fully understand our results, we may also use scanning electron microscopy, metallography, electron backscatter diffraction (EBSD) analysis, a comparison of resistance to wear of treated and untreated alloys, and a calculation of tensile strength.

Author(s): Gary Dawson, Stewart Grice, Dr. Andrew Nyce, Lanny Pease