Effect of nanocrystallization on tribological behaviors of ingot iron

Tribological behaviors of bulk nanocrystalline ingot iron (BNII) resulting from severe rolling with/without annealing have been compared with those of conventional polycrystalline ingot iron (CPII). The results reveal that in dry sliding the wear loss of BNII is higher than that of CPII, although its hardness is significantly enhanced. The wear loss of annealed BNII is the highest due to its lower hardness and the remains of sandwich structure as BNII. In lubricating sliding, the wear loss of BNII is obviously less than that of CPII, while the wear loss of annealed BNII is close to that of CPII. The frictional coefficient of BNII decreases at elevated temperature of the lubricant with additives, but CPII shows the contrary tendency. The reason for variation of tribological behaviors of tested samples is discussed preliminarily.