The development of the crystallographic texture in copper subjected to severe plastic deformation (SPD) by means of high pressure torsion (HPT) and equal-channel angular pressing (ECAP) was experimentally investigated and analyzed by means of computer modelling. It was demonstrated, that the texture developed in HPT and ECAP Cu is characterized by significant inhomogeneity. Therefore, the analysis focused on the study of the texture distribution and its inhomogeneity in sample space. The detailed texture analysis, based on the X-ray diffraction technique, led to important observations concerning the localization of the maximum texture gradient and the regularity of its changes related to the parameters of the applied deformation. The obtained results provided the basis for certain conclusions concerning complex texture changes in SPD Cu.
This paper presents methods of separating the plateau part for various types of two-process profiles, having the traces of two processes. The traditional method based on the plateau-valley threshold, according to the ISO 13565-3 standard, is not always sufficient, since the valley portion can include plateau roughness. Starting and finishing points of each plateau in the measured profiles should be determined. The procedure found in the technical literature depends on setting not only the plateau-valley threshold but also a lower threshold. This approach was a little modified for profiles that contain both random and deterministic topography components. A new procedure of determination of the lower threshold was proposed for stratified profiles containing two deterministic parts. The valleys can be characterized by their widths and the distance between them. In addition, a description of the material probability curve is proposed.
In this paper, an analysis of various factors affecting machined surface texture is presented. The investigation was focused on ball end mill inclination against the work piece (defined by surface inclination angle a. Surface roughness was investigated in a 3D array, and measurements were conducted parallel to the feed motion direction. The analysis of machined surface irregularities as a function of frequency (wavelength A), on the basis of the Power Density Spectrum - PDS was also carried out. This kind of analysis is aimed at valuation of primary factors influencing surface roughness generation as well as its randomness. Subsequently, a surface roughness model including cutter displacements was developed. It was found that plain cutting with ball end mill (surface inclination angle a= 0°) is unfavorable from the point of view of surface roughness, because in cutter’s axis the cutting speed vc ~ 0 m/min. This means that a cutting process does not occur, whereas on the machined surface some characteristics marks can be found. These marks do not appear in case of a* 0°, because the cutting speed vc * 0 on the fill I length of the active cutting edge and as a result, the machined surface texture is more homogenous. Surface roughness parameters determined on the basis of the model including cutter displacements are closer to experimental data for cases with inclination angles a* 0°, in comparison with those determined for plain cutting (a= 0°). It is probably caused by higher contribution in surface irregularities generation of plastic and elastic deformations cumulated near the cutter’s free end than kinematic and geometric parameters, as well as cutter displacements.
The paper presents theoretical analysis and simulation results of the process of regular surface texture generation by grinding with the wheel shaped in a special way. Simple variant of the method consists in grinding with the wheel having single helical groove. Non-uniform load of abrasive grains located in different zones of the wheel circumference was described. Two models (deterministic and probabilistic) of the wheel active surface were developed, assuming different grain arrangement. Results of two models were compared and differences were explained.
To obtain anti-corrosive thermo-diffusion zinc coatings, the authors use highly effective zinc saturating mixtures. This technology makes it possible to obtain coatings with a high zinc content in the δ-phase as well as a zinc-rich phase of FeZn13 (ζ-phase) on the coating surface. As a result of long-term studies into the corrosion properties of thermo-diffusion zinc (TDZ) coatings conducted by the authors, a number of features of their corrosive behavior have been established. The corrosion rate of those coatings in desalted and chloride-containing media is lower than those of galvanic or hot-dip zinc coatings. The corrosion behavior depends on the content of zinc on the surface and the texture features of the coating. The results showed that on the surface of thermo-diffusion coatings in the corrosion on media containing chloride ions, zinc hydroxychloride (simonkolleite – Zn5Cl2[OH]8[H2O]) has been formed. Compared to coatings obtained by other methods, the rate of simonkolleite formation was higher on TDZ coatings, which might have a positive effect on their resistance in aggressive atmospheres.
Activated tungsten inert gas (ATIG) welding has a good depth of penetration (DOP) as compared to the conventional tungsten inert gas (TIG) welding. This paper is mainly focused on ATIG characterization and mechanical behavior of aluminum alloy (AA) 6063-T6 using SiO2 flux. The characterization of the base material (BM), fusion zone (FZ), heat affected zone (HAZ) and, partially melted zone is carried out using the suitable characterization methods. The weld quality is characterized using ultrasonic-assisted non-destructive evaluation. A-scan result confirms that the ATIG welded samples have more DOP and less bead width as compared to conventional TIG. The recorded tensile strength of ATIG with SiO2 is better than the conventional TIG welding. The failure mode is ductile for ATIG welding with larger fracture edges and is brittle in the case of conventional TIG welding.
This paper presents a deep learning-based image texture recognition system. The methodology taken in this solution is formed in a bottom-up manner. It means we swipe a moving window through the image in order to categorize if a given region belongs to one of the classes seen in the training process. This categorization is done based on the Deep Neural Network (DNN) of fixed architecture. The training process is fully automated regarding the training data preparation, investigation of the best training algorithm, and its hyper-parameters. The only human input to the system is the definition of the categories for further recognition and generation of the samples (region markings) in the external application chosen by the user. The system is tested on road surface images where its task is to categorize image regions to a different road category (e.g. curb, road surface damage, etc.) and is featured with 90% and above accuracy.
The Goss texture is a characteristic feature of grain-oriented transformer steel sheets. Generator sheets, which are produced as non-oriented steel sheets, should have isotropic features. However, measurement results of generator sheets, confirmed by crystallographic studies, indicate that these sheets are characterized by certain, quite significant anisotropy. The first purpose of this paper is to present the influence of textures of generator and transformer steel sheets on their magnetization characteristics. The second aim is to propose a method which takes into account the sheet textures in the calculations of magnetization curves. In calculations of magnetization processes in electrical steel sheets, models in which the plane of a sheet sample is divided into an assumed number of specified directions are used. To each direction a certain hysteresis loop, the so-called direction hysteresis, is assigned. The parameters of these direction hystereses depend, among other things, on the texture type in these steel sheets. This paper discusses the method which calculates the parameters of these direction hystereses taking into account the given sheet texture. The proposed method gives a possibility of determining the magnetization characteristics for any direction of the field intensity changes.
The results of surface texture measurements obtained with the stylus equipment, white light interferometer
and confocal profilometer of the same samples were compared. Machined isotropic and anisotropic surfaces,
of symmetric and asymmetric ordinate distribution were measured. Forms were removed using polynomials.
Sampling intervals and measuring areas during computations of parameters were the same. Discrepancies
between the results obtained with various methods were observed and discussed. It was found that errors of
surface texture measurement with the optical methods depend on the type of surface topography.
The orientations of recrystallization nuclei and their adjacent as-deformed regions have been characterised in deformed single crystals of different metals (Ag, Cu, Cu-2%wt.Al and Cu-8%wt.Al) in which twinning and/or shear banding occur. {112}<111> oriented crystals of these metals have been compressed to different strains, then lightly annealed, and the crystallographic aspects of the recrystallization process along shear bands examined by local orientation measurement in TEM and SEM. The results clearly show the existence of a well-defined crystallographic relation between the local deformation substructure and the first recrystallized areas of uniform orientation. The first-formed nuclei always exhibit near 25–400(<111>–<112>) type misorientations, in the direction of highest growth, with respect to one of the two main groups of the deformation texture components. The rotation axes can be correlated with the slip plane normal of highest activity. As recrystallization proceeds, recrystallization twinning develops strongly and facilitates rapid growth; the first and higher generations of twins then tend to obscure the initial primary crystallographic relation between the shear bands and recrystallization nuclei .
Celem pracy była wstępna charakterystyka (mineralogiczna, chemiczna, teksturalna) odpadów poflotacyjnych, stanowiących surowiec uboczny (odpadowy) przy uzyskiwaniu koncentratów cynkowo-ołowiowych, pod kątem dalszych analiz nad możliwością ich perspektywicznego (eksperymentalnego) wykorzystania jako sorbentów gazów kwaśnych (SO2 i CO2). Składowisko tych odpadów jest własnością ZGH 'Bolesław' w Bukownie. Materiał badawczy stanowiła próbka odpadów poflotacyjnych pobrana ze stawu osadowego nr 1, leżącego w południowej części Stawu Zachodniego. Charakterystyka wytypowanych do badań materiałów obejmowała podstawowe badania mineralogiczne (XRD, SEM-EDS), analizy chemiczne (oznaczenie zawartości wilgoci analitycznej, zawartości strat prażenia, podstawowego składu chemicznego, jak też pierwiastków śladowych) oraz wyznaczenie podstawowych parametrów teksturalnych (powierzchnia właściwa BET, rozkład i wielkość porów). Badania mineralogiczne wykazały, że materiał odpadowy stanowią głównie minerały węglanowe (w przewadze kalcyt, dolomit, ankeryt) oraz minerały stanowiące pozostałość po niewyflotowanych kruszcach (w przewadze galena, sfaleryt). Analiza chemiczna pozwoliła stwierdzić, iż w analizowanej próbce dominują związki wapnia, magnezu i żelaza uwarunkowane przewagą minerałów węglanowych w badanych odpadach. Wśród pierwiastków śladowych przeważa arsen, następnie mangan i bar, występujące jednak w ilości nie przekraczającej 1%. Analiza teksturalna wykazała, że materiał badawczy charakteryzuje się niską powierzchnią właściwą i dużymi rozmiarami cząstek. Przeprowadzone badania sugerują, że analizowany materiał charakteryzuje się ubogimi właściwościami adsorpcyjnymi, aczkolwiek mógłby on znaleźć zastosowanie w metodach odsiarczania, jak też neutralizacji dwutlenku węgla (karbonizacja). Należałoby jednak w tym celu przeprowadzić dodatkowe badania wymywalności metali ciężkich w środowisku kwasowym, jak też zastosować domieszki innych składników, takich jak cement czy zeolity, w celu immobilizacji niebezpiecznych składników odpadów.
The objective of the study was to assess the potential use of optical measuring instruments to determine the minimum chip thickness in face milling. Images of scanned surfaces were analyzed using mother wavelets. Filtration of optical signals helped identify the characteristic zones observed on the workpiece surface at the beginning of the cutting process. The measurement data were analyzed statistically. The results were then used to estimate how accurate each measuring system was to determine the minimum uncut chip thickness. Also, experimental verification was carried out for each mother wavelet to assess their suitability for analyzing surface images.
We present a prototype of a simple, low-cost setup for a fast scatterometric surface texture measurements. We used a total integrated scatter method (TIS) with a semiconductor laser (λ = 638 nm) and a Si photodiode. Using our setup, we estimated the roughness parameters Rq for two reference surfaces (Al mirrors with flatness λ/10) and seven equal steel plates to compare. The setup is easily adaptable for a fast, preliminary manufacturing quality control. We show is possible to construct a low-cost measurement system with nanometric precision.
The objective of this research is to determine the impact of waves on the segregation of sediment within the area of its supply in the context of meteorological conditions. The research was conducted on a 4 km section of the shore of Calypsostranda (Bellsund, West Spitsbergen), shaped by waves such as swell, wind waves, and tides. Particular attention was paid to the diversity and variability of the surface texture within the intertidal zone. Meteorological measurements, recording of wave climate, as well as analysis of the grain-size distribution of the beach sediments were performed. Nearshore bathymetry, longshore drifts, episodic sediment delivery from land, as well as resistance of the shore to coastal erosion and direction of transport of sediments in the shore zone are important factors controlling shore development. Data show that wind waves contribute to erosion and discharge of material from the nearshore and intertidal zone. The research also shows that oceanic swell, altered by diffraction, reaching the shore of Calypsostranda contributes to better sorting of sediment deposited on the shore through washing it out from among gravels, and longshore transport of its finest fraction. The grain size distribution of shore sediments is significantly changed already during one tidal cycle. The degree of this modification depends not only on wave height and period but on the direction of wave impact. The shore of Calypsostranda can be regarded as transitional between high and low energy coasts.