Using M-2000 tribology machine, under non-lubrication, water-lubrication and oil-lubrication test situation, the tribology properties of three kinds of C/C composites were studied with the 40Cr steel as couple part. The results show that among the three kinds of test situation, the samples tested under non-lubrication situation own the highest friction coefficient and the least bulk worn loss under the same loading, and among the three kinds of composites tested under the non-lubrication test situation, the resin carbon matrix sample exhibits the highest friction coefficient that is between 0.141 and 0.205. The samples friction coefficient under water-lubrication test situation is the least that is between 0.05 and 0.10, but their bulk worn loss is the highest that can be 7.75 mm~3 under 150 N loading. Both friction coefficient and bulk worn loss of the samples under oil-lubrication test situation are the midst. The samples friction coefficient under non-lubrication test situation decreases slowly with increasing load, while those of the samples under water-lubrication or oil-lubrication test situation increase at first but decrease at last. SEM shows that the integrity friction film is only formed on the non-lubrication tested sample. The wear mechanism under all test situations is abrasion wear and plough wear.
This paper surveys the current study and the development of the network data measurements through the introduction of the research background of network data measurement,the detailed classification,summarization and analysis on the current research from the important aspects of the main technology in the field and the presentation of various data measurement technology to provide a perspective to some potential future research.
The corrosion thickness loss of a Ni-containing weathering steel and a common low-alloy steel Q420 was comparatively studied, by means of a dry- wet cyclic immersion test, which aims to simulate the atmospheric environment at coastal area. SEM and Raman spectroscopy were used to characterize the morphology, microstructure and phase composition of the formed rust scales. The results show that Ni has an important impact on the structure of weathering steel rust scale; the rust scale on weathering steel exhibits layered structure with an inner layer consisted mainly of α- Fe OOH, which seems to be stacked with small clusters resulting in a compact layer with good continuity and protectiveness. Besides the formed rust scale is strongly adhesive to the steel substrate so that to ensure the integrity of the rust scale during exposure in coastal environment with high salt content. In the contrast, the rust oxide scale on Q420 steel is so loose and porous with large sized grains of γ-Fe2O3 and Fe3O4hence its corrosion resistance is very poor. Furthermore, a relatively flat interface may not be favorable to the adhesion between the rust layer and Q420 steel substrate.
Fe-2Cu-0.6C powder metallurgy material was researched on microwave sintering.The properties and microstructure of microwave sintered sample were studied at different sintering temperatures,and microwave sintered samples were compared with conventional sintered samples under the same conditions.The results show that compared with the conventional sintering,microwave sintering samples have higher sintering density,higher tensile strength,greater elongation and equal Rockwell hardness.The optimum performance is obtained for microwave sintered samples sintered at 1150 ℃ for 10 min soaking,the sintered density is 7.20 g/cm3 which is the maximum density.The tensile strength is 413.90 MPa and hardness HRB is 75.Microwave sintered sample has finer microstructures,i.e.,small,rounded and uniformly distributed pores,which is advantageous to obtain the tiny crystal grain and high density.There are more flaky and granular pearlite than the conventional sintered samples,so microwave sintering can significantly improve the samples' performance.
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