Papers by Keyword: Microgeometry

Abstract: The article presents physical regularities for the formation of the surface layer microgeometry of the parts while edge cutting machining of steels from the standpoint of the metal temperature strength and the dislocation-energy concept of the metals failure in the process of cutting. It is proposed to employ an approach that contemplates the use of the informative ability of the thermo-emf signal as an integrated index for the thermophysical properties of a workpiece and a tool in mathematical relations as per roughness parameter calculation.

Abstract: Technological processes have a significant influence on the properties of the metallic formed pieces during production. Due to the plastic deformation, the shape of the component is changed and the degree of the structural anisotropy is increased - the orientation of the grain boundaries in the different parts of the component. It is important to identify these changes, to analyse them and optimize the technological processes. We get an important knowledge of relationship “technological parameters – microstructure – properties”. The article presents the results of the solution of a partial task from this area. It deals with changing of the geometric shape of the component when it is deformed. Specifically, the tubes (material EN SPT 360, STN 411 353) were drawn through the dies with different reduction angles. The dimensions (length and angle), roundness, cylindricity, coaxiality and surface roughness were evaluated.

Abstract: The analysis of geometry of abrasive grains on macrogeometrical and microgeometrical indicators is carried out; charts of distribution of these indicators are submitted. The research technique based on application of photometry for obtaining digital images of abrasive grains is described. On the basis of this method we have established that abrasive grains can be devided into following form types: isometric, beam-type, and laminar. Grains sharpening and peaks rounding radii R in samples scanning plane were investigated in order to analyse abrasive grains microgeometry. Statistic analysis provided following results: average grain sharpening angle is within limits of 85° ≤ β ≤ 90°; average grain peak rounding radius is equal to 0.2 ≤ R ≤ 0.4 mm.

Abstract: In this paper the way to numerical modeling of surface details after finishing is examined. Feature of the presented model is a sequence in the simulation results: at the beginning surface is modeled after processing by grinding and only then topography is modeled after burnishing. Simulation of a burnishing tool on close to real surface but not on the perfect surface allows considering the effect of technological heredity, which is important for the engineering manufacture.

Abstract: The aim of the work is find out influence of feed rate on the quality for the machined surface, especially surface roughness. The experiment was carried out by cutting tool HURCO VMXt30 with respect to the following cutting parameter: cutting speed 250; 350; 450; 550 and 850 m^.min^-1, feed 0,1; 0,5 and 1,0 mm/tooth. For testing was used two most common materials in the steel grade 1.1191 (12 050) and 1.2343 (19 552), and we chose two ordinary parameters of surface roughness; Ra - arithmetical mean roughness deviation and Rz - the largest inequalities height profile in the transverse direction and the longitudinal direction of machining. The structural equations will be the result which can describe the character depending on the cut surface parameters.

Abstract: In the present paper the influence of the reference system with regard to the characterization of the surface finishing is analyzed. The effect of the reference systems choice on the most representative surface finishing parameters (e.g. roughness average Ra and root mean square values Rq) is studied. The study can also be applied to their equivalent parameters in waviness and primary profiles. Based on ISO and ASME standards, three different types of regression lines (center, mean and orthogonal) are theoretically and experimentally analyzed, identifying the validity and applicability fields of each one depending on profiles geometry.

Abstract: Quality standards of polygraphic production are raising at the market. Hereupon a role of the surface of paper quality becomes more important and its ability of image reproduction. Particularly color reproduction quality is highly required. Samples of paper with different surface texture and structure were taken to investigation. Techniques of an estimation of properties of a surface of materials are presented. By results of work it is possible to track character of dependence between indicators of quality of a surface and a material color rendition. In this work presents investigation of microgeometry of paper and influence of this factor on color coverage area of printing system.

Abstract: The need for new cutting tool technologies is driven by the constantly increasing performance of machine tools and the rising market competition. Current research results show that an improved combination of the cutting edge macro- and microgeometry, together with an appropriate substrate and coating, leads to a significant enhancement of cutting tool performance. Furthermore, inappropriate cutting edge microgeometries cause, in addition to the higher production costs, a reduction of the tool life. Hence, it is essential to produce tailored cutting edge microgeometries with high precision and process reliability. This paper presents the influence of brushing process parameters on the size and the form of produced cutting edges of indexable inserts. This leads to a better understanding and higher quality of the cutting edge preparation process by means of abrasive brushes. Furthermore, the process reliability of 5-axes brushing is analyzed. An example of a tool life map presents the significantly enhanced tool performance through cutting edge preparation and its sensitivity towards varying the cutting edge microgeometry.