Gas carburized steel pretreated with shot peening, fine particle peening, and electrochemical polishing was subjected to rotating bending fatigue tests to investigate the effects of surface texture formed by peening on the fatigue properties. The results showed that the fatigue limit of carburized steel tended to decrease with increasing particle diameter used for peening. Furthermore, the fatigue limit of the carburized steels was proportional to the arithmetical mean waviness.

In this study, we investigated the structure and composition of amorphous carbon nitride films prepared using graphitic carbon nitride (g-C₃N₄) pellets and mixed pellets of g-C₃N₄ and hexamethylenetetramine (HMT) as the evaporation source for ion beam-assisted deposition. The amorphous carbon nitride films were deposited at acceleration voltages of 10 and 15 kV. In comparison with the g-C₃N₄ pellets, the ratio of nitrogen to carbon in the film was increased by using pellets of g-C₃N₄ mixed with 20 wt.% HMT. The main chemical bonding in the carbon nitride film changed from C-N=C to C-C by varying the acceleration voltage of the nitrogen ion beam. However, this change in chemical bonding was inhibited by the mixed pellets. The films prepared using g-C₃N₄ pellets with ion the beam at an acceleration voltage of 10 kV showed a low friction coefficient of 0.04 in friction testing under a nitrogen atmosphere.