Papers by Keyword: Roughness

Abstract: Dressing of grinding wheel is important value, which can influence final surface. Therefore, it is necessary to address this issue some attention. Dressing is used for sharpening of clogged and blunted grinding wheel and adjustement of their geometric shape. The article deals with one of the experiments that are carried out in this area at FPTM JEPU in Ústí nad Labem. Experiments refer specifically to impact assessment of dressing size on the final selected values of surface integrity. Within the article, the assessment covered the surface roughness Ra, Rz and Rt. At the same time were also scanned using a dynamometer Kistler components of the cutting forces and even here it was possible to observe the influence of the dressing size of the grinding wheel on these values.

Abstract: This article describes the electrochemical diagnosys system of oxide films corrosion properties of the thermal power equipment heating surfaces. It was found that the formation of oxide films on carbon steel surface in boiling water includes active dissolution with subsequent thermal conversion of the dissolution products into iron oxide (II). Forming films properties such as porosity and roughness change in multi repeating way, which includes the alternation of loosening and consolidation processes.

Abstract: Thermal spraying process is one of the main methods of obtaining the protective coatings. Coating quality largely depends on the proper selection of coating materials, technology and spraying equipment and the method of substrate preparation. The article presents the problem of the effect of surface preparation process on selected properties of the coating produced by supersonic thermal spraying – HVOF. Blast cleaning and supersonic thermal spraying processes were characterized. The influence of blasting parameters on the resulting surface profile and selected properties of the coating, such as roughness, porosity and structure were determined by means of surface profilometry, light microscopy and digital image analysis.

Abstract: The tool edge preparation has a significant influence on the quality of the workpiece surface, the stability of the cutting process and the tool life. In order to investigate the effect of the tool edge preparation, the impact on the cutting force components, the roughness and the residual stress is analyzed through the response surface methodology. The paper presents experimental results of turning tests with different edge radius and changing the cutting speed, the feed amount per tooth, the axial depth, and the radial depth. The research results will put forward theoretical value and practical significance to develop the processing technology of high-speed and efficient cutting, improve the metal cutting theory and prompt the development of the manufacture industry.

Abstract: This paper presents a prediction and evaluation of surface roughness based on Taguchi’s method and the analysis of variance (ANOVA). The experiments were conducted on aluminium 6061 reinforced with 5% SiC to study the surface roughness under various cutting conditions. The objective was to establish a correlation between current, pulse on time flushing pressure with the surface roughness in the metal matrix composite (MMC). The correlation was obtained by multi-variable linear regression and compared with the experimental results.

Abstract: Swirling Fluidized Bed Polishing (SFBP) is a non–traditional alternative abrasive flow surface finishing form of Fluidized Bed Machining (FBM) in which the former has special features to overcome certain significant limitations of the latter, namely the variation of the surface roughness vertically along the component surface and the screening effect owing to the complex contours in the work piece geometry. Owing to its ability to perform machining and generate polished surface from a roughness value of Ra 1.2μ to 0.2 μ within 8 hours of processing, this new method offers greater scope in the surface modification of rough machined surfaces with complex geometry such as component with ducts and grooves. This research focus on investigating the effect of abrasive particle concentration on metal removal rate per unit area of the specimen surface. 3D surface morphology analysis investigates the quality of the polished surface and the study of circumferential uniformity and machining accuracy analysis on a complex-contoured component further investigate its scope and relevance in industrial applications.

Abstract: Water jet cutting is one of the newest techniques in non-conventional machining processes. It is a flexible technology since the same equipment can be used to cut virtually any material, such as steel stainless steel, high-nickel alloys and polymer composites (usually, for these materials, the water jet is mixed with an abrasive material, the process being known as abrasive water jet cutting - AWJC) . Compared with the classical technologies, water jet cutting presents the following advantages: very low side forces during machining, it is rapid, it is silent, no thermal distortion, a good cutting accuracy and minimal burrs. To optimize the process, it is necessary to analyze the influence of process parameters on the quality of cut. The aim of this paper is to analyze the influence of distance between the cutting head and the working sample on the quality of cut, quantified by the following parameters: width of the processed surface at the jet inlet, jet outlet, deviation from perpendicularity, inclination angle and roughness.

Abstract: For this study with high originality, a teflon bushing with outer diameter of 58 mm and 32 mm internal diameter has been turned. After inner turning with various cutting feeds, the part has been cut in half to measure roughness. The roughness parameters Ra, Rz and Rq have beeen measured with an electronic roughness tester Mitutoyo, Japan, SJ-201 P. The micro-asperity images for each of the 6 samples performed are presented in the paper. Diagrams with the variations of roughness parameters are also given in this study. The trend is the increasing of roughness values with feed increasing, but some abnormalities also appear in samples 3 and 4 for Ra and Rz. At sample 5 for Rz parameter and sample 6 for Rq parameter a decreasing of values occurs, although geometrically there should be with ascending tendencies. It follows that in teflon turning the cutting process is not uniform, although there are no marks on the blade. However, because this material is not metallic, it does not have a uniform structure, which influences the resulted roughness. This is the cause of the anomalies established by these experiments.

Abstract: Frequently, on the drawings of mechanical parts, only indications concerning the surface roughness parameter Ra and, relatively rarely, the surface roughness parameter Rz are included. However, the study of the machined surface roughness highlights the necessity to use yet other surface roughness parameters, in order to have a clearer image on the state of the machined surface. Some other surface roughness parameters possible to be used and presenting importance, without the parameters Ra and Rz, were highlighted. One took into consideration the possibility of measuring parameters Rsk and Rmr by means of the available surface roughness testers. Experimental researches of turning by applying the method of full factorial experiment were developed. As input factors in turning process, the cutting speed, the feed rate and the tool nose radius were used. The experimental results were mathematically processed, being determined empirical mathematical models that highlight the influence of certain input factors of turning process on the values of some surface roughness parameters characterized by a more restricted use

Abstract: Industrial parts with complex shapes are characterized by thin sections and complex geometries. Rapid vacuum casting is an ideal technology to manufacture complicated parts in small series production or prototypes. Contributions regarding simulation and analyzing of the parts made by rapid vacuum casting technology are presented in this study. Using dedicated software for simulating the casting process was analyzed and optimized the time of casting, the complete filling with material and also reducing the surface defects.