Abrasive wear response of nanocrystalline Ni–W alloys across the Hall–Petchbreakdown

The abrasive wear of nanocrystalline Ni–W alloys with grain sizes of 5–105 nm has been studied using Taber abrasion testing. The wear resistance of the finest grain size specimen is found to be higher than would be predicted based on hardness alone. This deviation from Archard scaling is traced to mechanically-driven structural evolution, consisting of grain growth and grain boundary relaxation, which occurs during wear. Comparison of these observations with previous wear studies suggests that the extent of structural evolution during wear depends on contact stresses and material removalrates.