Iranian Journal of Materials Science and Engineering

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Surface smoothness of ceramic glazes is always an important characteristic of ceramic glazes as a point of surface engineering studies. Surface roughness affects chemical resistivity, glossiness and stainabiliy of glazes. In fact, less surface roughness improves cleanability of the surface by the least usage amount of detergents. In this investigation, surface topography of two common opaque glazes, zirconia and titania-based, has been investigated. Crystallinity of the surface has been studied from SEM images, and comparison of EDS elemental results with phase analysis results of XRD. Surface roughness profile measured by Marsurf M300, shows that titania-based glaze is almost 24% percentage more smooth than zirconia based glaze. Surface smoothness is in relation with crystallinity of glaze surface, crystal type and crystal distribution in amorphous matrix phase

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A full factorial design of experiment was applied running 36 experiments to investigate the effects of milling parameters including cutting speed with three levels of 62.83, 94.24 and 125.66 m/min, feed rate with three levels of 0.1, 0.2 and 0.3 mm/tooth, cutting depth with two levels of 0.5 and 1 mm and machining media with two levels, on surface integration properties of magnesium AZ91C alloy such as grain size, secondary phase percent, surface microhardness and surface roughness. In all cases, a fine grained surface with higher secondary phase sediment and microhardness obtained comparing the raw material. According to analysis of variance results, the most effective parameter on grain size, secondary phase percent and microhardness was cutting depth and the most effective parameter on surface roughness was feed rate. although the grain size in all machined samples was smaller than that of the raw material but due to the dual effect of cryogenic conditions, which both cool and lubricate and reduce the temperature and strain rate at the same time, the direct effect of this parameter on grain size was not significant. Also, the all interaction effects of parameters on grain size and microhardness were significant.

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Fluorinated graphene is an up-rising member of the graphene family and attracts significant attention since it is a 2D layer-structure, is self-lubricating, has wide bandgap and high thermal and chemical stability. By adjusting the C–F bonding character and F/C ratios through controlled fluorination processes, fluorinated graphene can be utilized for a wide range of applications including energy conversion, storage devices, bio- and electrochemical sensors. Herein, monolayer CVD graphene/Cu was fluorinated via SF₆ plasma with time and power sequence trial. Structural, morphological, roughness, adhesive forces, and wettability of fluorinated graphene was explored. Insight was gained by Raman spectroscopy, SEM and EDS, surface roughness and adhesive force measurements via AFM on different samples. Fluorination produced p-doped structure, blue shift in the 2D peak and red shift in D peak of the Raman spectra of graphene. Increase in plasma time increased the defects and weakened C-C bonds much more rapidly at higher plasma power (40W) while lower plasma power (15W) retained more of graphene properties (having high L_a, L_D and low n_D) confirmed by Raman, SEM and EDS analyses. Surface roughness and adhesive forces on graphene surface were mostly increased with the increase in plasma time at a certain power. Higher plasma power resulted in more hydrophobic surfaces and even the wettability tuning occurred in the hydrophobic regime while lower plasma power demonstrated tuning in the hydrophilic regime. Influence of the underlying surface and π -electron pairs were shown to play more significant roles in tuning the wettability at higher plasma power.