Effect of nanoparticles on the tribo-layers and the tribology of a steel-on-steel couple

The tribological behavior and tribo-layers of AISI 1045 steel sliding against 52100 steel were investigated in the case of supplying MoS2, Fe2O3, and their mixtures onto the sliding interface. When nanoparticles were supplied, tribo-layers were formed on the worn surfaces. The tribological behavior of the sliding pair depended on the characteristics of tribo-layers, which were decided by different nanoparticles. As the additives—especially the ones containing MoS2—were supplied onto the sliding interface, the wear rates and friction coefficients of both 1045 steel and 52100 steel were markedly decreased to extremely low values, approaching zero and marginally undulated with the increase in load. Single-component Fe2O3 nanoparticles markedly reduced the wear rate of 1045 steel with slightly increased friction coefficient, but its decreased extent was merely half of that of the additives containing MoS2. The improvement of the tribological performance of steels was attributed to the formation of protective tribo-layers. The addition of pure Fe2O3 resulted in the formation of insert-type tribo-layers, while cover-type tribo-layers were formed by the addition of the mixture additives of Fe2O3+MoS2 and pure MoS2. The cover-type tribo-layers provided more protective and lubricative functions than that of the insert-types.

Crystallization of Cordierite-Based Glass-Ceramics Adding with Fe2O3-TiO2

The effect of Fe2O3-TiO2 mixture additives on the crystallization behaviour of a parent glass with composition located in the primary field of cordierite within the MgO-Al2O3-SiO2 system has been examined. The crystallization behaviour of the glass was determined by differential thermal analysis (DTA) and X-ray diffraction (XRD). The microstructure was characterized by scanning electron microscopy (SEM). The results show that additives of Fe2O3-TiO2 can lower the temperature of the crystallization peak (Tp) and promote crystallization of the parent glass. By controlled thermal treatment, the main crystal phase obtained was Fe2+substituted α-cordierite. The approach outlined in this paper to obtain heterogeneous ion substituted cordierite glass-ceramics is useful to develop infrared radiation material with good properties.