Abstract.The paper overall the way and principle of how to modify activated carbon at home and abroad. Besides, the characteristics was given on physical, chemical modification respectively. The physical modification generally changed internal and external structure of the activated carbon, while chemical modification changed both its structure and surface properties. The advantages，disadvantages and the mechanism of the modifiers mentioned above are discussed，and their application are also prospected.

The impact wear resistance of the hard coating is very important in the high-temperature environment of the nuclear power plant. CrN and CrAlN coatings were prepared using multi-arc ion plating. The impact abrasive wear resistance of the coatings was investigated at varied temperatures through a controlled kinetic energy impact wear rig, and their impact mechanism was elucidated. No extensive spalling was found on the surface of the CrN and CrAlN coatings after 104 impacts under the no-sand condition. The excellent antioxidant properties of the CrN and CrAlN coatings can protect the substrate from oxidation under the no-sand condition at 500 °C. The impact mechanism of the two coatings was plastic deformation under the no-sand condition, and it was mainly material removal under the sand condition. The depth and width of wear scar were larger under the sand condition than under the no-sand condition. The impact wear region was divided into a mixed impact zone and a sand impact zone. Compared with the CrN coating, the CrAlN coating had lower impact force and shallower impact wear scar, proving that it has better anti-impact wear properties.

The impact wear property of hard coatings at elevated temperatures is of particular interest for applications in nuclear power plants. This study evaluated the impact wear behavior of two CrAlN/TiSiN coatings with and without sand. Alternately grown CrAlN and TiSiN films with modulation periods of 455 and 19 nm were formed in a columnar structure. The nanomultilayer shows better impact wear resistance than multilayer films with and without sand. The energy absorption rate has a similar trend to wear rate, leading to lower rebound velocity and peak impact force of the nanomultilayer compared with that of the multilayer. CrAlN/TiSiN coatings can protect the 308L substrate from oxidation. The dominant impact wear mechanism without sand is plastic deformation, and this wear region can be defined as the percussive zone. Peeling occurs on the multilayer surface without sand after 104 percussions, leading to rapid oxidation of the 308L substrate at 500 °C. Due to the abrasion effect, the wear rate of the sample with sand increases by an order of magnitude compared to the sample without sand. The wear scar of the sample with sand can be divided into the mixing zone and the sand−affected zone from inside to outside. Fe oxides are formed beyond the unbroken coating, which may be related to the outward diffusion of Fe.

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The aim of this study is to investigate the effect of SiC particle pretreatment, aluminum matrix particle size and sintering temperature on relative density, hardness, microstructure and wear resistance to SiC particle einforced aluminum matrix composites. To this end, the amount of 16.7 wt.% SiC with average particle sizes 20μm was used along with pure aluminum of average particle size of 75 μm and 25μm. Powder metallurgy is a method used in the fabrication of this composite in which the powders were mixed using a planetary ball mill. By analyzing SEM micrograph and the Property test, it is concluded that SiC particle pretreatment has significant effect on the morphology of pecimens. pretreatment increase the interface adhesion, improve the wettability. SiC is uniformly distributed in the matrix, with good relation to the substrate, the maximum hardness is 51.1HB, the minimum wear rate is 0.1684%, while the density is 97.3%.For the same SiC content and particle size, the smaller the particle size of aluminum matrix is, the higher wear resistance of composite materials is on condition that others are same, the higher sintering temperature and the higher the wearability of composites, the wear resistance of the composite material is significantly improved after SiC pre-processing.The relative density increases with increasing aluminum matrix particle sizes under the same pressure and the holding time. The actual density of all samples reached the theoretical density over 96%, to a maximum of 98.9%.