Wojciech Kapłonek

Analysis of Flatness Deviations for Austenitic Stainless Steel Workpieces after Efficient Surface Machining

Abstract The following work is an analysis of flatness deviations of a workpiece made of X2CrNiMo17-12-2 austenitic stainless steel. The workpiece surface was shaped using efficient machining techniques (milling, grinding, and smoothing). After the machining was completed, all surfaces underwent stylus measurements in order to obtain surface flatness and roughness parameters. For this purpose the stylus profilometer Hommel-Tester T8000 by Hommelwerke with HommelMap software was used. The research results are presented in the form of 2D surface maps, 3D surface topographies with extracted single profiles, Abbott-Firestone curves, and graphical studies of the Sk parameters. The results of these experimental tests proved the possibility of a correlation between flatness and roughness parameters, as well as enabled an analysis of changes in these parameters from shaping and rough grinding to finished machining. The main novelty of this paper is comprehensive analysis of measurement results obtained during a three-step machining process of austenitic stainless steel. Simultaneous analysis of individual machining steps (milling, grinding, and smoothing) enabled a complementary assessment of the process of shaping the workpiece surface macro- and micro-geometry, giving special consideration to minimize the flatness deviations

The Use of Focus-Variation Microscopy for the Assessment of Active Surfaces of a New Generation of Coated Abrasive Tools

Abstract In this paper, the selected results of measurements and analysis of the active surfaces of a new generation of coated abrasive tools obtained by the use of focus-variation microscopy (FVM) are presented and discussed. The origin of this technique, as well as its general metrological characteristics is briefly described. Additionally, information regarding the focus variation microscope used in the experiments - InfiniteFocus® IF G4 produced by Alicona Imaging, is also given. The measurements were carried out on microfinishing films (IMFF), abrasive portable belts with Cubitron™ II grains, and single-layer abrasive discs with Trizact™ grains. The obtained results were processed and analyzed employing TalyMap 4.0 software in the form of maps and profiles, surface microtopographies, Abbott- Firestone curves, and calculated values of selected areal parameters. This allowed us to describe the active surfaces of the coated abrasive tools, as well as to assess the possibility of applying the FVM technique in such kinds of measurements.

Coherence Correlation Interferometry in Surface Topography Measurements

Assessment of surface topography can be done by various methods, especially stylus and optical methods as well as utilising scanning tunneling microscopes and atomic force microscopes (Whitehouse, 1994, 2003; Thomas, 1999; Wieczorowski, 2009). The most accurate techniques for assessing surface topography include optical methods (Leach, 2011), especially methods of interference (Pluta, 1993; Hariharan, 2007). In the last two decades, there have been rapid developments in interferometry, as a result of the new possibilities for digital recording and analysis of interference images. The fastest growing interference methods include Phase Stepping Interferometry (PSI) (Creath, 1988; Stahl, 1990; Kujawinska, 1993; Creath & Schmit, 2004) and methods based on coherence analysis of light reflected from the test and reference surfaces (Harasaki et al., 2000; Blunt & Jiang, 2003; Schmit, 2005; Blunt, 2006; Petzing et al., 2010). This second group of methods is defined in different terms in English (Petzing et al., 2010; Leach, 2011), for example:  Coherence Correlation Interferometry (CCI),  Coherence Probe Microscopy (CPM),  Coherence Scanning Microscopy (CSM),  Coherence Radar (CR),  Coherence Scanning Interferometry (CSI),  Coherence Scanning Microscopy (CSM),  Scanning White Light Interferometry (SWLI),  Vertical Scanning Interferometry (VSI),  White Light Scanning Interferometry (WLSI).

Morphology of Near- and Semispherical Melted Chips after the Grinding Processes Using Sol-Gel Abrasives Based on SEM-Imaging and Analysis

Selected issues related to SEM-imaging and image analysis of spherical melted chips formed during the grinding process are presented and discussed. The general characteristics of this specific group of machining products are given. Chip formation phenomena, as well as their overall morphology, are presented using selected examples of near- and semispherical melted chips occurring singly or concentrated in clusters on the grinding wheel surface after the machining process. Observation of the spherical melted chips and acquisition of their images were carried out for grinding wheel active surfaces with microcrystalline sintered corundum abrasive grains SG™ after the internal cylindrical grinding process of a 100Cr6 steel and Titanium Grade 2® alloy by use of a scanning electron microscope, JEOL JSM-5500LV. Analysis of the obtained SEM micrographs was carried out by Image-Pro® Plus 5.0 software to determine the selected geometrical parameters describing the morphological features of the assessed chips.

The use of high-frequency acoustic emission analysis for in-process assessment of the surface quality of aluminium alloy 5251 in abrasive waterjet machining

In this article, the use of acoustic emission signal analysis for in-process assessment of the surface quality in abrasive waterjet machining is presented. The authors carried out an analysis of the influence of the cutting head traverse speed (considered in this case as the performance measurement) on the flatness, waviness and roughness of surfaces made of aluminium alloy 5251 after cutting process, as well as the influence of changing the quality factor on values of selected descriptors of the emitted high-frequency acoustic emission signal processed in the frequency domain. This was a new approach, different from the norm, in which an acoustic emission signal is usually studied for low frequencies. The obtained results confirmed the clear influence of machining conditions on the geometric structure of the obtained cuts and the registered values of the emitted stress waves. This influence can be accurately determined by the use of the high-frequency acoustic emission signal analysis being proposed. Additionally, statistical dependence models developed between the given process quality indicator and the registered selected acoustic emission signal parameters in the frequency domain allowed for the prediction of the surface texture of the obtained cuts on the basis of the acoustic emission signal emitted during the machining process.

The effect of active surface morphology of grinding wheel with zone-diversified structure on the form of chips in traverse internal cylindrical grinding of 100Cr6 steel

The article presents the results of experimental investigations to determine the effect of active surface morphology of grinding wheels with a zone-diversified structure on the form and size of chips generated during traverse internal cylindrical grinding of 100Cr6 steel. In the grinding process involving grinding wheels with a zone-diversified structure, chip formation phenomena differ in the rough and finish grinding zones of the tool. In order to expand one’s knowledge of this phenomena, the microtopography measurements of the grinding wheel active surface in the rough and finish grinding zones were made, as well as scanning electron microscopic observations of these areas after the dressing cut and following internal cylindrical traverse grinding. The conducted studies showed that chips in the rough grinding zone of the grinding wheel active surface are usually several hundred micrometers in length. In the finish grinding zone, however, mainly micro-chips were generated whose length does not exceed 100 µm (usually around 10 µm in length). In the rough grinding zone, shearing-type and flowing-type chips dominate with a few examples of spherical melted chips. Moreover, in the finish grinding zone, mainly slice-type and knife-type micro-chips were observed.

Analysis of the effects of the single abrasive-grain microcutting scratch on INCOLOY® Alloy 800HT® by using advanced CLSM-SEM techniques

Knowledge and understanding of modern machining processes requires, in many cases, not only the use of typical surface topography methods but also imaging methods such as numerous varieties of advanced confocal laser scanning microscopy and scanning electron microscopy. This work demonstrated that these microscopic techniques can be successfully used for accurate measuring and analyzing of the effects of the scratch tests. The experimental tests were carried out on the internal cylindrical sample surface made of INCOLOY® alloy 800HT®, with the traces shaped by a single abrasive grain of microcrystalline sintered corundum SG™. One of the traces formed was prepared for gathering more advanced measurements in order to determine the most important elementary phenomena dominant during the microcutting process. These measurements were carried out using the 3D laser microscope LEXT OLS4000 by Olympus and an electron microscope JSM-5500LV by JEOL with X-ray spectrometer module INCAPentaFET-x3 and a Si(Li) detector manufactured by Oxford Instruments, as well as an opto-digital microscope DSX500 by Olympus (used as a reference instrument). All measurement data acquired were analyzed using dedicated software, which significantly improved the possibilities for effective interpretation of the results obtained from the experimental tests. Analysis of the test results showed that the microcrystalline sintered corundum abrasive grain generates scratches with a highly developed morphology on the workpiece surface. On the abrasive grains were observed both signs of fracture wear due to mechanical and thermal shock loads as well as abrasive wear of the abrasive grain active vertexes.

Identification of Surface Quality of Plastic Electrodes after Blasting

Nowadays, plastics have become one of the most demanded materials, replacing the traditional ones such as metals. Therefore, many companies are concerned with the production of plastics, with their distribution and innovation development. Plastics have found utility in a wide range of applications, we use them every day. Measurement of surface roughness of plastic moldings produced by the injection molding process was carried out by a contact profilometer Mitutoyo Surftest SJ401. A reason for this measurement is to obtain information about surface roughness. For further technical adjustment is required to have higher surface roughness what helps to increase electrical conductivity of plastic moldings. This involves determination of a ratio between Ra/Rz (the ratio between the arithmetic average of the roughness profile Ra and the average maximum height of the profile Rz) in order to satisfy customer demand for achieving better surface characteristics leading to an increase in electrical conductivity.