Microstructure dependence of abrasive wear behavior in electrodeposited nanocrystalline Ni - P alloy

Abstract

Effect of microstructure on two-body abrasive wear behavior in electrodeposited Ni -4.4 mass% P alloy was investigated to obtain a clue to development of nanocrystalline materials with high wear resistance. The as-electrodeposited nanocrystalline Ni -4.4 mass% P alloy, which was in a supersaturated solid-solution, transformed into a dual phase alloy composed of Ni and Ni₃P grains as a result of the precipitation of Ni₃P phase by annealing. The Hall-Petch relationship between the hardness and average grain size was maintained in the annealed dual phase alloy specimens with average grain size ranging from 50 nm to 1230 nm. The wear rate of the annealed specimens decreased with decreasing average grain size accompanied by hardening. The wear rate of the annealed specimens containing hard Ni₃P grains was lower than that of the as-electrodeposited specimen with the similar hardness. Although the very fine grain size induced smooth wear grooves, the conventional grain size induced rough wear grooves with turning of Ni phase. The hardness dependence of wear resistance in Ni -4.4 mass% P alloy specimens was weaker than that obtained in the case of pure metal specimens with different hardness.