The effect of an additive 0.5 wt. % zirconium oxide on the spark plasma sintering (SPS) kinetics alumina powders has been studied. Ceramics were obtained by mixing in a planetary mill with grinding media from stabilized oxide. activation energy SPS was estimated using Young-Cutler model. It shown that density and average grain size ceramics submicron are significantly affected nonequilibrium st...

Grinding is finishing process aimed at achieving surface quality and dimensional accuracy in workpieces with tight tolerances especially from materials with a high degree of hardness and strength. The grinding process of superalloys is faced with problems and challenges caused by the generation of excessiveheatas well as the adhesion of workpiecematerialon the grinding tool. Therefore, in-depth...

Two of the important parameters in grinding operation are surface roughness of the workpiece and the amount of consumed energy. These parameters are strongly affected by the condition of grinding wheel surface which is dependent on the dressing parameters. Predicting the roughness of the grinding wheel surface after dressing with known dressing parameters can improve the grinding process. Resea...

The grinding process consists of an abrasive contact between a moving workpiece and a wheel in rotation [1]. Because of the grinding power converted into heat at the interface, high temperatures can appear that can lead to thermal, mechanical or metallurgical consequences. Each of these effects has been fully related in literature by authors. Guo presents a good review of surface layers (dark, ...

The purpose of this study was to evaluate grinding efficiency in abutment teeth comprising both dentin and core composite resin in the axial plane. Grinding was performed over 5 runs at two loads (0.5 or 0.25 N) and two feed rates (1 or 2 mm/sec). The grinding surface was observed with a 3-D laser microscope. Tomographic images of the grinding surfaces captured perpendicular to the feed directi...

Kinetics and mechanism of hydrogen adsorption in as-obtained ground nuclear graphite Wendelstein 7-X are examined. In the first time interval process is determined by dissociation molecule, occurring at outer surface open micropores particles. However, second interval, slowest step inter-granular inter-crystallite diffusion nanopores graphite. The X-ray analysis shows, that grinding results fin...

A family of Ce-doped LaCoO 3 perovskites are presented as possible catalysts for Cl–VOCs elimination. These materials with different contents Ce were obtained through the citrate and reactive grinding methods. The insertion in original perovskite structure favours presence Co 2+ /Co 3+ /Ce 4+ redox pairs a higher content oxygen vacancies that enhances catalytic performance chlorobenzene combust...

The purpose of our study is to investigate the heat distribution and the occurring temperatures during grinding. Therefore, we did both experimental and numerical investigations. In the first part, we present the integration of an infrared thermopile array in a steel workpiece. Experiments are done by acquiring data from the thermopile array during grinding of a groove in a workpiece made of st...

Semi-Autogenous Grinding mills can be optimized for maximum ore throughput or maximum grinding energy efficiency. In both cases, precise control of the mill weight is critical. Model predictive control provides an additional tool to improve the control of Semi-Autogenous Grinding mills and is often able to reduce process variability beyond the best performance that can be obtained with proporti...

The objective of this study was to determine the effect of different sugar beet pulp (SBP) pretreatments on biogas yield from anaerobic digestion. SBP was subjected to grinding, thermal-pressure processing, enzymatic hydrolysis, or combination of these pretreatments. It was observed that grinding of SBP to 2.5-mm particles resulted in the cumulative biogas productivity of 617.2 mL/g volatile so...