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EN
The article presents an analysis of the turning parameters of two non-ferrous materials. The tested materials were: brass CuZn39Pb3 and aluminum alloy AW 6060. A Kyocera turning knife and a WNMG 080404 AH plate were used to make the samples. Three parameters were tested: rotational speed, feed and depth of cut at three levels of variability. The roughness parameters Ra and Rz were selected for the analysis. On the basis of the obtained results, it was shown that the feed used during machining has the greatest influence on roughness, while the change of depth or cutting speed does not cause significant differences in roughness.
PL
W artykule przedstawiono analizę parametrów toczenia dwóch materiałów nieżelaznych. Materiałami poddanymi badaniom były: mosiądz CuZn39 Pb3 i stop aluminium AW 6060. Do wykonania próbek użyto noża tokarskiego firmy Kyocera i płytki WNMG080404AH tej firmy. Badaniom poddano trzy parametry: prędkość obrotową, posuw i głębokość skrawania na trzech poziomach zmienności. Do analizy wybrano parametr chropowatości Ra i Rz. Na podstawie uzyskanych wyników wykazano, że największy wpływ na chropowatość ma posuw stosowany podczas obróbki, natomiast zmiana głębokości czy tez prędkości skrawania nie powoduje znaczących różnić w chropowatości.
EN
The influence of polylactide (PLA), polycarbonate (PC), polyacrylic photo resins and polyamide 11 (PA11) on the surface roughness of anatomical models structures of the mandible made with additive techniques was investigated. Measurements of the model surfaces geometric structure were carried out using a 3D contact profilometer. Selected roughness parameters and three-dimensional visualization of the tested models surface roughness are presented.
PL
Zbadano wpływ polilaktydu (PLA), poliwęglanu (PC), żywic foto poliakrylowych i poliamidu 11 (PA11) na chropowatość powierzchni modeli struktur anatomicznych żuchwy wykonanych technikami przyrostowymi. Pomiary struktury geometrycznej powierzchni modeli przeprowadzono przy użyciu profilometru stykowego. Przedstawiono wybrane parametry chropowatości oraz trójwymiarowe wizualizacje chropowatości powierzchni badanych modeli.
EN
In this study, the effects of calcite and mica contents in nepheline syenite (NS) samples beneficiated by high intensity dry magnetic separation and flotation methods on ceramic bodies were investigated in detail. The NS samples were, first, sintered to observe the physical and surface roughness properties, and characterized based on the change of NS samples such as color, shrinkage, water absorption, and surface roughness after the sintering process. L-a-b color and Ra, Rz, Rt values for the NS samples were determined. The decrease in calcite and mica contents affected the surface of sintered specimens positively by reducing roughness values. Additionally, the water absorption values were found to be directly proportional to Ra values for unglazed surfaces. In conclusion, calcite and mica minerals in NS samples negatively affected surface quality by forming pinholes due to dehydroxylation and outgassing reactions in the sintering process.
PL
W artykule przedstawiono dalsze rezultaty badań eksperymentalnych dotyczących wpływu wybranych czynników procesu szlifowania na stan powierzchni elementów obrotowych. Opis pierwszej części zawarty jest w numerze 3/2022. W tej części analizowano wpływ granulacji ziaren ścierniwa na chropowatość obrabianych powierzchni, a także związek między parametrami obciągania ściernicy a stanem powierzchni po obróbce. Stwierdzono zróżnicowaną istotność tych czynności.
EN
In the paper, further carried out experimental studies on the effects of selected grinding process factors on surface properties were presented. The description of the first part is given in No 3/2022. This section investigations the effects of granulation of abrasive grains on the surface roughness of the treated surfaces were contained. The relationship between the parameters of the grinding wheel dressing and the condition of the surface after machining were presented too. Different relevance of these factors was found.
PL
W artykule przedstawiono badania wpływu geometrii płytek tokarskich na chropowatość powierzchni. Obróbce toczeniem poddano dwa rodzaje stali: 1.0503 (C45) oraz 1.6582 (34CrNiMo6) w formie wałka o średnicy Ø 50. Badano otrzymaną chropowatość powierzchni toczonych trzema rodzajami płytek DCET 11T3005R (z geometrią ostrza Wiper), WNMG080404, VBMT160404. Wyniki badań jednoznacznie wykazały, że powierzchnie obrobione płytkami typu Wiper charakteryzują się mniejszymi wartościami parametrów chropowatości niż obrobione płytkami o geometrii standardowej.
EN
In this paper investigates how the geometry of turning plates affects the surface roughness were described. Two steel types were machined: 1. 0503 (C45) and 1. 6582 (34CrNiMo6) in the form of a shaft with a diameter of Ø50. The resulting surface roughness was investigated with three plate types DCET 11T3005R (with Wiper geometry), WNMG080 404, VBMT160 404. The test results clearly showed that surfaces treated with Wiper geometry plates have lower roughness parameters than plates with standard geometry.
PL
W pracy przedstawiono zagadnienia dotyczące określenia zależności matematycznej pomiędzy prędkością skrawania, a parametrem chropowatości Ra. Wykazano, że istnieje silna ujemna korelacja między w/w badanymi zmiennymi.
EN
In this paper investigations concerning the determination of the mathematical relationship between the cutting speed and the roughness parameter Ra were presented. A strong negative correlation between the studied variables was demonstrated.
EN
To improve the screw machining accuracy in modern air compressors. This paper investigates three main issues during the development process for cycloid screw machining methods on five-axis CNC machine tools with high precision and efficiency. First, the theoretical basis of cycloid screw surface shaping and derivative of the final profile equation is established. Then, modeling the center trajectory and feed rate according to the cycloid screw profile is given. Next is the experimental setup and simulation of the cycloid screw machining process and discussions. The obtained surface quality prediction parameters are close to the actual measured value, which can be used as a reference model for five-axis CNC milling technology processes. All experimental results obtained by the proposed mathematical model show that a surface with good surface quality is created, meeting the requirements for surface quality. The main work can be used as references for engineers and technicians in practice.
EN
In this paper fundamental information on the influence of the real machined surfaces generated by different machining processes on the fatigue life of machine parts are presented. In the first part the various approaches for the assessment of the stress concentration factor and the correction of a fatigue life limit are discussed. In the second part the results of standard fatigue tests are compared with computed data and predictions using FEM based simulations. The effect of surface discontinues (valleys) in the real surface profiles is related to engineered parts made of different materials including steels, aluminium alloys, aerospace alloys and composites.
EN
In the present study, the arithmetical mean roughness (Ra) values obtained as a result of drilling glass fiber reinforced polymer (GFRP) composite material produced in fiber orientation angles (0º/90º) with different drill bits in a 5-axis CNC controlled vertical machining center, were analyzed. The experimental design was applied with the Taguchi method. The drilling experiments were performed using Minitab 19 software according to the Taguchi L18 orthogonal array. The test results were evaluated based on the signal-to-noise (S/N) ratio. Two different drill bits (HSS and carbide), three different spindle speeds (750, 1000, 1500 rpm) and three different feed rates (0.05, 0.10, 0.15 mm/rev) were selected as the control factors. The effect levels of the control factors on Ra were found by applying analysis of variance (ANOVA). A confidence level of 95.62% was obtained with ANOVA analysis. The lowest Ra value was 1.279 μm at the spindle speed of 1500 rpm and the feed rate of 0.05 mm/rev using a carbide drill bit. The drill bit type was obtained as the parameter with the highest effect with a rate of 61.33%.
EN
This paper presents a comparative study on the effects of the in-situ surface modifications performed on “H” type microfluidic systems obtained via additive manufacturing. The microsystem was printed using a polylactic acid filament on an Ender-5 Pro printer. The surface modification of the main channel was done using chloroform by two different methods: vapor smoothing and flushing. The obtained surface roughness was studied using an optical microscope and the ImageJ software, as well as scanning electron microscopy. The effect of the channel surface treatment upon the characteristics of the fluid flow was assessed. The microfluidic systems were used for the dynamic study of biofilm growth of Candida albicans (ATCC 10231). The influence of the surface roughness of the main channel on the formation and growth of the biofilm was studied using quantitative methods, scanning electron microscopy imaging as well as optical coherence tomography.
EN
Flap peening (FP) is a cold working technique used to apply a compressive force using small shots, this will lead to enhance the surface properties that it can sustain for long life during working conditions. In this study, several aircraft aluminum alloys materials namely; 2219 T6, 2024 T6, 7075 T6, and 6061 T6 were flap peened under different rotational speeds. The effect of rotational speed on the average surface roughness (Ra) and average surface micro hardness have been investigated. As seen by the Scanning Electron Microscope SEM phots that the hardness of peened layer is increased. It was found that as the flap peening speeds increase the percent change in surface roughness (Ra) increases, and the percent change in surface micro hardness decreases. The maximum increase in Ra occurs in 2219 T80 and the minimum in 6061 T6 alloys, and for hardness, it is reported that the maximum occurs in 6061 T6 and the minimum in 2019 T80 alloy.
EN
In this paper, a study was carried out to investigate the surface roughness and material removal rate of low carbon NiTi shape memory alloy (SMA) machined by Wire Electro Spark Erosion (WESE) technique. Experiments are designed considering three parameters viz, spark ON time (SON), spark OFF time (SOFF), and voltage (V) at three levels each. The surface roughness increased from 2.1686 μm to 2.6869 μm with an increase in both SON time, SOFF time and a decrease in voltage. The material removal rate increased from 1.272 mm3/min to 1.616 mm3/min with an increase in SON time but a varying effect was observed the SOFF time and voltage were varied. The analysis revealed that the intensity and duration of the spark had an unswerving relation with the concentration of the microcracks and micropores. More microcracks and micropores were seen in the combination of SON = 120 μs, voltage = 30 V. The concentration of the microcracks and micropores could be minimised by using an appropriate parameter setting. Therefore, considering the surface analysis and material removal, the low carbon NiTi alloy is recommended to machine with 110 μs - 55 μs - 30 V (SON - SOFF - V respectively), to achieve better surface roughness with minimal surface damage.
EN
The Inconel 718 alloys, which are primarily temperature resistant, are widely used in aviation, aerospace and nuclear industries. The study on dry cutting processes for this alloy becomes difficult due to its high hardness and low thermal conductivity, wherein, most of the heat transfers due to friction are accumulated over the tool surface. Further, several challenges like increased cutting force, developing high temperature and rapid tool wear are observed during its machining process. To overcome these, the coated tool inserts are used for machining the superalloys. In the present work, the cemented carbide tool is coated with chemical vapor deposition multi-layering Al 2O 3/TiCN under the dry cutting environment. The machining processes are carried out with varying cutting speeds: 65, 81, 95, and 106 m/min, feed rate 0.1 mm/rev, and depth of cut 0.2 mm. The variation in the cutting speeds can attain high temperatures, which may activate built-up-edge development which leads to extensive tool wear. In this context, the detailed chip morphology and its detailed analysis are carried out initially to understand the machining performance. Simultaneously, the surface roughness of the machined surface is studied for a clear understanding of the machining process. The potential tool wear mechanism in terms of abrasion, adhesion, tool chip off, delaminating of coating, flank wear, and crater wear is extensively identified during the processes. From the results, it is observed that the machining process at 81 m/min corresponds to a better machining process in terms of lesser cutting force, lower cutting temperature, better surface finish, and reduced tool wear than the other machining processes.
EN
The paper presents the effect of technological parameters of vibratory shot peening on the roughness and microhardness of the surface layer of shot peened objects. Moreover, the surface topography results from vibratory shot peening was analyzed. In the experiment, samples made of 1.4301 stainless steel were used, which were cut by abrasive water jet (AWJ). The geometrical structure of the surface after vibratory shot peening was changed. The surface roughness was obtained in the range of Rsk = -0.600 ÷ -1.115 and Sa = 3.01 ÷ 6.53 μm, The value of microhardness ΔHV, near to the surface, is from 36 HV0.05 to 100 HV0.05. The changes in microhardness reach on the depth gh = 100 μm. An analysis of variance ANOVA for the investigated dependent variables was performed. The Tukey's test was used to checked the influence of the independent variable on the dependent variable. The aim to obtain favorable properties of the surface layer of elements after abrasive water jet cutting, it is recommended to use a vibratory shot peening time of approx. 6 minutes and balls of diameter d = 6 mm.
EN
In the cutting process, when the cutting edge leaves the material, burrs are often formed on the edges of the workpiece. Due to inconveniences associated with burrs, such as problems with properly fixing the workpiece on the machine for further processing or problems with parts working in assemblies, deburring operations must be performed. In addition to that, burrs may pose danger for workers at the production stage and for customers at the stage of using the finished product. One of the popular deburring methods is brushing. Apart from deburring, brushing can be used to change surface layer properties. The aim of this study is a comparative analysis of the effect of machining with wire and ceramic brushes on microhardness and the surface quality of EN AW-7075 aluminium alloy. Results show that, for all defined brushing conditions, lower surface roughness parameters are obtained when using ceramic brushes rather than wire brushes. In contrast, the use of wire brushes leads to increased microhardness of the surface layer.
EN
Nowadays, great emphasis is placed on increasing the efficiency of machining processes. However, this cannot be done at the expense of quality worsening of the machined surface. In this paper the influence of Wiper geometry on Ra and Rz surface roughness parameters is described when finishing turning of materials used in the aviation industry: austenitic stainless steel XCrNiNb18-9, low alloy steel 14NiCr14 and aluminum alloy A356, as well as the chips generated in the cutting process in terms of shape were assessed. It was found that for the lowest tested feed rate during turning with a Wiper insert, the values of Ra and Rz parameters do not differ significantly from the roughness parameters obtained during machining with a conventional insert. The beneficial effect of feed rate on surface roughness for the Wiper insert is clearly visible above f ≥ 0.12 mm/rev. The biggest difference in roughness parameters was recorded for the highest value of the applied feed f = 0.28 mm/rev. Using conventional insert, Ra and Rz values are almost three times bigger than for Wiper insert. The influence of the cutting speed on the Ra and Rz parameters depends on the type of material being processed. Increasing cutting speed from vc =120 m/min to vc = 200 m/min for stainless steel, Ra and Rz values decrease about 35%. Similar situation noticed for aluminum alloy, but increasing cutting speed decrease Ra and Rz values only about 18%. The situation is different for low alloy steel. Increasing the cutting speed increases the Ra and Rz parameters by about 37%. Rz/Ra ratio shows that for feed rate f ≤ 0.12 mm/rev. cutting process is unstable, because the values are between 5.5–7.5, but should oscillate around 4. Increasing feed rate value to f = 0.2 mm/rev allows to stabilize the process and the ratio value is close to 4. Wiper insert create the same form chips as a conventional insert, using the same value of feed rate.
EN
The purpose of this paper is to study the behaviour of transient elastohydrodynamic contacts subjected to forced harmonic vibrations, including the effect of surface waviness for concentrated counterformal point contact under isothermal conditions. Profiles of pressure and film thickness are studied to reveal the combined effects of sinusoidal external load and surface roughness on the lubrication problem. The time-dependent Reynolds' equation is solved using Newton–Raphson technique. The film thickness and pressure distribution are obtained at different snap shots of time by simultaneous solution of the Reynolds’ equation and film thickness equation including elastic deformation and surface waviness. It is concluded that the coupling effects of the transient sinusoidal external load and wavy surface would result in increase in modulations of the pressure and film thickness profile in comparison to the case where the smooth contact surfaces are subjected to sinusoidal external load.
EN
The shaping of structural elements of flexible discs formed from synthetic diamond powders on synthetic binders is one of the current problems facing researchers when creating new, highly effective machining tools for the processing of mineral materials. Over many years, natural stone and particularly hard types of rock have been used for and still remain a noble, durable and highly appreciated building material for facings. Meeting the normative requirements for shaping functional properties in automated technology systems for processing such materials requires the development of methods for modeling new construction and material solutions for machining tools, especially with the use of diamond abrasives, which are increasingly used in construction technologies. One requirement is to study the influence of the geometrical form of the abrasive segments of flexible machining discs in order to increase the efficiency of the process of finishing granite surface grinding.
PL
Kształtowanie elementów konstrukcyjnych elastycznych tarcz formowanych z syntetycznych proszków diamentowych na spoiwach syntetycznych stanowi jeden z aktualnych problemów w zakresie badań nad tworzeniem nowych wysoko efektywnych narzędzi obróbczych do obróbki materiałów mineralnych. Kamień naturalny, szczególnie twarde rodzaje skał, od lat były i nadal pozostają szlachetnym trwałym i wysoko docenianym materiałem budowlanym, stosowanym jako materiał okładzinowy. Spełnienie normatywnych wymagań w zakresie kształtowania właściwości użytkowych w zautomatyzowanych systemach technologii obróbki takich materiałów wymaga opracowania sposobów modelowania nowych rozwiązań konstrukcyjno-materiałowych narzędzi obróbczych szczególnie z wykorzystaniem ścierniwa diamentowe go, które w technologiach budowlanych znajdują coraz większe zastosowanie. Jednym z nich jest zbadanie wpływu formy geometrycznej segmentów ściernych elastycznych tarcz obróbczych w celu zwiększenia efektywności procesu szlifowania wykończeniowego powierzchni płyt granitowych.
EN
The article presents the results of a geometrical surface texture study of cycloid drive discs after bench tests. For this purpose, the working surfaces, such as peak and valley areas of the epicycloid and the holes inner surfaces of both discs, were investigated using contact profilometry. From each surface, a transverse profiles were extracted, before and after 50 cycles of bench test. The discs and the profiles were examined for signs of wear and roughness changes. For each profile, the Ra and Rz roughness parameters were determined. On the base of the obtained profiles and the values of roughness parameters, it can be stated that the assumed test parameters provide stable working conditions, with an uninterrupted lubrication film, which results in practically negligible and unmeasurable wear. Taking into account the operating specification of a helicopter winch as an example of potential application of the presented cycloidal drive, the developed solution fulfils the requirements concerning wear resistance
PL
W artykule zaprezentowano wyniki badań laboratoryjnych trwałości kół przekładni cykloidalnej. W tym celu z powierzchni współpracy kół wyodrębniono obszary szczytu i doliny powierzchni epicykloidalnej, a także wewnętrzne powierzchnie otworów, które poddano badaniom przy użyciu profilometrii stykowej. Dla każdej z powierzchni wyznaczono profile chropowatości przed i po 50 cyklach testu stanowiskowego. Koła, jak również profile zostały poddane analizie pod kątem obecności śladów zużycia i zmian chropowatości. Dla każdego z uzyskanych profili wyznaczono parametry chropowatości Ra i Rz. W oparciu o uzyskane profile i wartości parametrów chropowatości można stwierdzić, że przyjęte parametry testowe zapewniają stabilne warunki pracy z nieprzerwanym filmem smarowym, czego efektem jest niemalże pomijalne, niemierzalne zużycie. Jednym z przykładowych zastosowań opracowanej przekładni cykloidalnej jest wyciągarka śmigłowcowa, a biorąc pod uwagę specyfikę jej pracy, uzyskane rozwiązanie konstrukcyjne spełnia wymagania dotyczące zapewnienia wystarczającej odporności na zużycie.
PL
Celem pracy było zbadanie wpływu kierunkowości struktury geometrycznej, uzyskanej w procesie szlifowania, na nośność jednozakładkowych połączeń klejowych wykonanych ze stali S235JR oraz ze stopu aluminium 2024-T3. Badania przeprowadzono dla pięciu różnych wariantów połączeń różniących się kierunkiem szlifowania i ułożeniem szlifowanych powierzchni klejonych względem siebie. Wyniki badań wskazują, że w przypadku połączeń ze stali, najkorzystniejszym rozwiązaniem pod względem nośności złącza jest szlifowanie powierzchni klejonych pod kątem 45 ̊ względem kierunku działania siły obciążającej złącze i sklejenie ich w taki sposób, aby utworzona tekstura się krzyżowała (nośność połączeń Pt = 4667,36 N). Natomiast w przypadku połączeń ze stopu aluminium, najkorzystniejszym rozwiązaniem jest szlifowanie powierzchni klejonych prostopadle względem kierunku działania siły obciążającej złącze (nośność połączeń Pt = 3210,46 N). Wyniki testu znaczących różnic (test-t) wskazują, że w przyjętym zakresie zmienności parametrów wejściowych, kierunkowość struktury geometrycznej ma istotny wpływ na nośność połączeń klejowych.
EN
The aim of the work was to investigate the influence of the directivity of the geometric structure obtained in the grinding process on the load capacity of single-lap adhesive joints made of steel S235JR and aluminum alloy 2024-T3. The research was carried out for five different variants of joints differing in the direction of grinding and the arrangement of the ground surfaces to each other. The test results show that in the case of steel joints, the most advantageous solution in terms of joint load capacity is grinding the adhesive surfaces at an angle of 45 ̊ to the direction of the force loading the joint and connecting them in such a way that the created texture crosses (joint load capacity Pt = 4667.36 N). However, in the case of joints made of aluminum alloy, the best solution is to grind the adhesive surfaces perpendicular to the direction of the force loading the joint (joint load capacity Pt = 3210.46 N). The results of the significant difference test (test-t) show that in the assumed range of variability of the input parameters, the directionality of the geometric structure has a significant impact on the load capacity of the adhesive joints.
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