Ograniczanie wyników
Czasopisma help
Autorzy help
Lata help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 562

Liczba wyników na stronie
first rewind previous Strona / 29 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  surface roughness
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 29 next fast forward last
1
Content available Chropowatość powierzchni makro- i mikroelementów
PL
Miniaturyzacja urządzeń i wdrażanie nowych technologii stwarzają konieczność stosowania małych przekrojów przewodów, stąd też rosną wymagania i zapotrzebowanie związane ze stosowaniem mini- i mikrokanałów. Modele przepływowe oraz dotyczące wymiany ciepła opracowane i sprawdzone dla makrokanałów nie uwzględniają zjawisk istotnych w mikrokanałach, a różnica zwiększa się wraz ze zmniejszaniem się wymiaru charakteryzującego przepływ i metodą obróbki powierzchni. W artykule przedstawiono przykłady mikrourządzeń i wpływ chropowatości powierzchni makro- i mikroelementów na parametry pracy urząd.
EN
Miniaturization of devices and implementation of new technologies create the necessity of application of small cross-section conduits, hence requirements and demand associated with the use of microchannels is growing. Flow and heat transfer models developed and validated for macrochannels do not account for phenomena relevant in microchannels, and the difference increases with decreasing dimensions characterizing the flow and methods of surfaces machining. In this paper examples of microdevices and the effect of macro and microelement surface roughness on devices performances were presented.
PL
Zaproponowano sposób obliczeniowego oszacowania wpływu zużycia narzędzi skrawających na intensywność zużywania korozyjnego warstwy wierzchniej materiału obrabianego. Cechą charakterystyczną podejścia jest ocena stopnia zużycia korozyjnego w zależności od zużycia narzędzia, parametrów chropowatości powierzchni przedmiotu obrabianego i stopnia utwardzania warstwy wierzchniej na zimno, a także parametrów warunków obróbki technologicznej (parametrów skrawania, geometrii narzędzia skrawającego, właściwości obrabianego materiału i narzędzia).
EN
A possible variant for calculated estimation of the degree of the impact of the cutting tool wear on the value of the part’s surface layer wear obtained during processing with the edge tool, due to atmospheric corrosion, is presented. The feature is the evaluation of the wear rate and its numerical value depending on the tool wear, roughness parameters of the work piece surface, and the degree of cold hardening of the surface layer, as well as parameters of the technological machining conditions (cutting conditions, geometry of the tool cutting part, properties of the machined and the tool materials).
EN
In the paper, the results of the comparative studies of the surface roughness, as obtained after face milling, with the application of standard cutting inserts and Wiper inserts, have been discussed. The presented results of the studies show in what technological conditions it is possible to obtain the best effects of reducing the surface roughness.
PL
W artykule przedstawiono wyniki badań porównawczych chropowatości powierzchni, uzyskanych po obróbce frezowania czołowego, przy wykorzystaniu standardowych płytek skrawających oraz płytek typu Wiper. Zaprezentowane rezultaty badań pokazują, w jakich warunkach technologicznych obróbki można uzyskać najlepsze efekty obniżenia chropowatości powierzchni.
EN
The purpose of the article was to deepen the state of knowledge regarding the impact of surface roughness on the capacity of single-lap adhesive joints from aluminum alloy 2024. The surfaces with a triangular outline and various height and longitudinal parameters have been deliberately shaped. The surface roughness of the samples was shaped by milling with four different table feed of 30, 50, 70 and 90 [mm/min]. Surface roughness was tested in a 2D system using a contact profilometer. The samples were connected using Loctite EA 3430 epoxy adhesive and then subjected to a static tensile test. As a result of the performed statistical analysis, it was shown that in the adopted variability area, along with the increase of the feed value, the value of roughness parameters and the capacity of joints increased. The highest capacity was obtained for the parameters Ra = 20,83 μm, Rz = 101,33 μm, Rv = 41,97 μm, Rku = 2,62 μm, RSm = 0,746 mm.
PL
Celem artykułu było pogłębienie stanu wiedzy dotyczącej wpływu chropowatości powierzchni na nośność jednozakładkowych połączeń klejowych stopu aluminium 2024. W sposób celowy ukonstytuowano powierzchnie o zarysie trójkątnym, różniące się wysokościowymi i wzdłużnymi parametrami chropowatości. Chropowatość powierzchni próbek kształtowano poprzez frezowanie z czterema różnymi prędkościami posuwu wynoszącymi 30, 50, 70 i 90 [mm/min]. Chropowatość powierzchni zbadano w układzie 2D przy pomocy profilometru stykowego. Próbki sklejono z wykorzystaniem kleju epoksydowego Loctite EA 3430, a następnie poddano statycznej próbie rozciągania. W wyniku przeprowadzonej analizy statystycznej wykazano, że w przyjętym obszarze zmienności wraz ze zwiększaniem wartości posuwu zwiększała się wartość parametrów chropowatości oraz nośność połączeń. Najwyższą nośność uzyskano dla parametrów Ra = 20,83 μm, Rz = 101,33 μm, Rv = 41,97 μm, Rku = 2,62 μm, RSm = 0,746 mm.
EN
The article presents the analysis of the impact of surface roughness on the load capacity of lap adhesive joints from aluminum alloy 2024. The surfaces of the samples were prepared to bond using mechanical treatment methods, such as milling and abrasive blasting. The surface roughness of the samples for different pre-treatment variants, measured in the 2D system, was found in the range of: Rp=19,4÷60,6 [μm], Rv=16,5÷88,1 [μm], Rz=35,9÷147,0 [μm], Rc=32,2÷103,3 [μm], Rt=37,1÷174,7 [μm], Ra=8,91÷22,73 [μm], Rq=10,50÷27,33 [μm], Rsk=-0,2260÷0,6487, Rku=1,78÷5,85, RSm=0,1207÷0,7337 [mm], Rdq=23,4÷198,7 [˚]. Strength tests showed an increase in the bearing capacity of joints the surfaces of which were subjected to both milling and abrasive blasting.
PL
W artykule przedstawiono analizę wpływu chropowatości powierzchni na nośność zakładkowych połączeń klejowych stopu aluminium 2024. Powierzchnie próbek zostały przygotowane do klejenia z zastosowaniem metod obróbki mechanicznej, takich jak frezowanie i piaskowanie. Chropowatość powierzchni próbek dla poszczególnych wariantów obróbki, zmierzona w układzie 2D, mieściła się w przedziale: Rp=19,4÷60,6 [μm], Rv=16,5÷88,1 [μm], Rz=35,9÷147,0 [μm], Rc=32,2÷103,3 [μm], Rt=37,1÷174,7 [μm], Ra=8,91÷22,73 [μm], Rq=10,50÷27,33 [μm], Rsk=-0,2260÷0,6487, Rku=1,78÷5,85, RSm=0,1207÷0,7337 [mm], Rdq=23,4÷198,7 [˚]. Badania wytrzymałościowe wykazały wzrost nośności połączeń, których powierzchnie poddawane były zarówno frezowaniu, jaki i piaskowaniu.
EN
The article concerns an investigation of 100Cr6 steel surface peripheral grinding process with glass-crystalline bonded grinding wheels. More precisely the investigation of surface roughness parameters and grinding force components in relation to different dressing overlap ratio, feed rate and grinding depths values. Seven different values of dressing overlap ratio have been used to determine influence of dressing overlap ratio to grinding force and surface roughness. After determining the stable range of dressing overlap ratio, other tests were conducted with eleven different values of feed rate and two values of grinding depth to determine how they shape the grinding force components and surface roughness parameters. The machining has been performed using a CNC surface grinding machine, together with a surface grinding wheel and up grinding strategy. Additional NI equipment was used for grinding force data acquisition. The surface roughness was assessed using two parameters (Ra, Rz). The contact measurements of surface roughness were carried out using the MarSurf PS 10 profilometer. The dresser effective width was measured with the use of AM7515MZT Dino-Lite microscope to ensure consistent values of dressing overlap ratio throughout the entire experiment. Significant impact of the dressing overlap ratios, feed rate and grinding depths on the grinding force components Fn and Ft as well as the roughness parameters Ra and Rz were obtained.
PL
Artykuł dotyczy badań procesu szlifowania obwodowego stali 100Cr6 za pomocą ściernic o spoiwie szklanokrystalicznym. Dokładniej dotyczy badań parametrów chropowatości powierzchni i składowych sity szlifowania w odniesieniu do różnych wartości wskaźnika pokrycia przy obciąganiu, posuwu i głębokości szlifowania. Siedem różnych wartości wskaźnika pokrycia przy obciąganiu zostało wykorzystanych do określenia wpływu wskaźnika pokrycia na siłę szlifowania i chropowatość powierzchni. Po określeniu stabilnego zakresu wskaźnika pokrycia przy obciąganiu przeprowadzono kolejne badania z jedenastoma różnymi wartościami posuwu i dwiema wartościami głębokości szlifowania, aby określić ich wpływ na składowe sity szlifowania i parametry chropowatości powierzchni. Obróbka została wykonana przy użyciu szlifierki CNC do płaszczyzn wraz ze ściernicą obwodową i strategią szlifowania przeciwbieżnego. Dodatkowo do pomiarów sity szlifowania zostało wykorzystano oprzyrządowanie NI. Chropowatość powierzchni została oceniona za pomocą dwóch parametrów (Ra, Rz). Pomiary stykowe chropowatości powierzchni przeprowadzono przy użyciu profilometru MarSurf PS 10. Czynna szerokość obciągacza byle mierzona przy utyciu mikroskopu Dino-Lite AM7515MZT, aby zapewnić stale wartości wskaźnika pokrycia przy obciąganiu w trakcie wszystkich wykonywanych badań. W efekcie uzyskano istotny wpływ wskaźnika pokrycia przy obciąganiu, posuwu i głębokości szlifowania na składowe sity szlifowania Fn i F Ft oraz na parametry chropowatości Ra i Fz.
EN
Hard machining is a process which has become highly recommended in manufacturing industry to replace grinding and perform production. The important technological parameters that determine this process are tool wear, machined surface roughness, cutting force and morphology of the removed chip. In this work, an attempt has been made to analyse the morphology and form of chip removed during turning of hardened steel AISI 1045 (40HRC) with mixed ceramic tool type CC650. Using a Taguchi plan L9, whose factors are cutting speed and feed rate with three levels for each. Macroscopic and microscopic results of chip morphology were correlated with these two cutting parameters additional to surface roughness. Sufficient experimental results were obtained using the mixed ceramic tool when turning of hardened steel AISI 1045 (40HRC) at high cutting speeds. Roughness of machined surface confirmed that it is influenced by feed rate. Chips show a sawtooth shape for all combinations of the experimental plan used. The chip form changed with cutting parameters variation and given an important indicator of suraface quality for industriel. Having the indicators on the surface quality from simple control of chip without stopping machining give an important advantage in order to maximize production and reduce costs.
EN
The aim of the conducted research was to examine the possibility of using chemical and physical methods of surface treatment of elements printed on a 3D printer. Elements were printed from polylactide (PLA) and acrylonitrile-butadiene-styrene (ABS) – materials most commonly used in fused filament fabrication (FFF) technology. Roughness measurements were made to assess the quality of individual methods. The best surface smoothness results were obtained during abrasive paper processing and after applying epoxy resin. The intended effect was also obtained after processing samples from PLA in chloroform fumes, and ABS samples in acetone vapors.
PL
Zbadano możliwości wykorzystania chemicznych i fizycznych metod obróbki powierzchniowej elementów wydrukowanych za pomocą drukarki 3D. Elementy wytworzono z polilaktydu (PLA) i kopolimeru akrylonitrylo-butadieno-styrenowego (ABS) – materiałów najpowszechniej stosowanych w technologii Fused Filament Fabrication (FFF). Jakość wykonania przy użyciu poszczególnych metod oceniano na podstawie chropowatości powierzchni wytworzonych elementów. Najlepszą gładkość powierzchni uzyskano w wyniku obróbki wydrukowanych elementów papierami ściernymi i nałożeniu żywicy epoksydowej. Zamierzony efekt uzyskano też w wyniku obróbki próbek z PLA w oparach chloroformu, a próbek z ABS w oparach acetonu.
EN
Surface roughness of particles plays an important role in bubble-particle interaction process. However, the continuous attachment and detachment process have rarely been characterized between the surface of different roughness and air bubble. In this study, the continuous attachment and detachment processes between the surface of different roughness and air bubble were investigated by a highly sensitive microbalance. The bubble–surface interaction process was monitored by a high-speed camera to analyze the geometry parameters, including distance, adhesion diameter, and contact angle. It was found that the bubble-particle attachment time increased with the increase of surface roughness. The magnitude of the repulsive force in the bubble-surface approaching process increased with the increase of surface roughness, while the attractive force in the bubble-particle retracting process decreased monotonically with the surface roughness. The force measured by microbalance was finally compared with the calculated one. The calculated force at the biggest force point also increased with the decrease of surface roughness. These results indicate that coal particles with lower surface roughness, which have less water-filled pores and pillars, is more conducive to flotation due to the lower repulsive force in the bubble-particle attachment process and higher adhesive force in the bubble-particle detachment process, and vice versa.
EN
From ancient days to till today manufacturing industries, especially making of holes on the parts during drilling process for precision assembling of parts facing problems with burr formation. Drilling operation is one of the finishing operation in the production cycle, removing of burrs during drilling process is a time consuming and non-value added process to the manufacturing sector. So reducing the size of burrs is the main aim of the present study. In the present work, optimization of burr size is considered during drilling of aluminium 7075 alloy. In this connection, experiments are conducted based on Grey based Taguchi. From Grey relational grades of responses selected optimal combination of parameters to attain multiple performance characteristics of responses with a corresponding higher grey relational grade. For identifying the most significant input parameters that influence the output responses ANOVA is conducted. Based on interaction effect plots of data means of responses from results of ANOVA, confirmation tests are conducted by choosing most significant parameters. Finally, observations reveals that feed rate, point and clearance angles are the most influential factors on burr size and also experimental results divulge that the lower the thrust force causes to decrease the burr height. The proposed approach is helpful to the budding entrepreneurs in the related areas to select optimal combination of drilling parameters to attain multiple performance characteristics of responses especially in burr size to prevent the post finishing operations up to certain extent.
EN
High-quality products include those with better surface quality and texture, close dimensional tolerances and form accuracies at precise level, increase fatigue life and burr-free. Burr formation is one of the most common inevitable facts occurring in all material removal processes, reduces assembly and machined part quality. But, burr formation during milling is a more complex mechanism compare to remaining machining burrs and leads to numerous difficulties during the deburring process. To prevent this, one should optimize the combination of cutting parameters during machining itself. In order to build up a link between quality and productivity and to attain the same in the cost-effective way, the present work concentrate on multi objective optimization of CNC end milling process parameters. Multiple performance characteristics with respect to surface quality and performance index like assembly work have been put up, to assess an equivalent single quality index (called grey relational grade) has been optimized finally by Grey based Taguchi method. After that priority weight of individual quality and performance attributes has been estimated by entropy measurement technique on the basis of relative significance and check the feasibility of the proposed technique has been demonstrated in this context.
PL
W artykule przedstawiono ocenę stanu makroskopowych naprężeń własnych w tytanie, gatunku G4, wyznaczonych metodą rentgenograficzną sin2ψ. Porównywano wartości naprężeń zmierzone w materiale wyjściowym i w próbkach o sub/mikrostrukturze otrzymanej po obróbce plastycznej w plastomerze Gleeble, przy: temperaturze 875 K, zoptymalizowanym odkształceniu ε i prędkości odkształcenia έ. Po kulowaniu, niezależnie od zróżnicowania struktury, chropowatość polerowanych powierzchni próbek zwiększyła się niekiedy nawet ok. 10-krotnie. Niewielkie różnice wystąpiły w twardości, większej w bardziej plastycznej sub/mikrostrukturze, co też znalazło odzwierciedlenie i w wielkości naprężeń własnych.
EN
The article presents the assessment of the macroscopic residual stresses in titanium, grade G4, determined by the sin2ψ X-ray method. The values of stresses measured in the source material and in samples of sub/microstructure obtained after plastic processing in the Gleeble plastometer at the temperature 875 K, optimized strain ε and strain velocity έ were compared. After shot peening, regardless of the structure diversity, the roughness of the polished surfaces of the samples sometimes increased even about 10 times. Small differences occurred in hardness, higher in the more plastic sub/microstructure, which was also reflected in the magnitude of internal stresses.
EN
In this study, machining characteristics of polymer composite consisting of banana fiber and silicon carbide (SiC) as reinforcements and epoxy resin as matrix are investigated. Reinforcement phases consist of raw banana fiber powder sieved to 100 microns size of 1% (w/w) and SiC powder of 1% (w/w). The conventional machining process is carried out on the fabricated composite samples by considering the depth of cut, feed rate and speed as influential parameters. The central composite design (CCD) is used to design the experiment based on response surface methodology (RSM). The analysis of variance (ANOVA) is used to study the influences of the depth of cut, feed rate and the speed on the material removal rate (MRR) and surface roughness. The results reveal that the feed rate is the most influential parameter for minimizing surface roughness and maximizing MRR. It is observed that the feed rate plays an important role in determining the surface roughness and MRR followed by the depth of cut and speed. The optimized parameters for maximum MRR and minimum surface roughness are also obtained.
EN
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.
15
Content available remote Study on the use of Aerogel on the Surface of Basalt Fabric
EN
The layer of aerogel was applied to the surface of basalt fabric due to the possibility of improving a fabric protecting against the influence of hot environmental factors. The analysis of aerogel surface roughness and thickness of the obtained sample, resistance to contact heat for the contact temperature between 100°C and 250°C, and tests of resistance to the penetration of thermal radiation were carried out. In addition, thermal conductivity, thermal resistance, thermal diffusion, thermal absorption, and surface roughness were determined. The obtained results indicate the unevenness of aerogel application on the surface of basalt fabric. For this reason, work should be carried out on an appropriate technology that will allow them to be applied evenly on the surface of the fabric. The parameters tested and the results obtained are promising in terms of the possibility of using the fabric obtained in protective gloves.
EN
This article proposes these of vibratory machining to Ti-6Al-4V titanium alloy as finishing treatment. Titanium alloy was used in the aerospace industry, military, metallurgical, automotive and medical processes, extreme sports and other. The three-level three-factor Box-Behnken experiment examined the influence of machining time of vibratory machining, the type of mass finishing media used and the initial state of the surface layer on the mass loss, geometric structure of the surface, micro hardness and the optimal process parameters were determined. Considerations were given the surfaces after milling, after cutting with a band saw and after the sanding process. The experiment used three types of mass finishing media: polyester, porcelain and metal. Duration of vibratory machining treatment was assumed to be 20, 40, 60 minutes. The form profiles before and after vibratory machining were determined with the Talysurf CCI Lite - Taylor Hobson optical profiler. Future tests should concern research to carry out tests using abrasive pastes with a larger granulation of abrasive grains, to carry out tests for longer processing times and to determine the time after which the parameters of geometrical structure of the surface change is unnoticeable.
EN
The effects of surface preparation on the corrosion resistance of AISI 316L austenitic stainless steel were studied using the cyclic potentiodynamic polarization method. Grinding, mechanical polishing, and electropolishing were considered as the surface modifier methods. Regarding the surface roughness parameters, besides the conventional height parameter (Ra), the kurtosis (Rku) as the shape parameter was also considered to rationalize the pitting resistance for the first time. Based on the results of the Tafel extrapolation method, it was revealed that the uniform corrosion can be adequately correlated to Ra. However, the pitting resistance was found to mainly relate to the kurtosis, where by decreasing Rku (increased bluntness of topographic features), the pitting resistance enhanced. It was also found that a surface with Rku less than three (platykurtic) is resistant to pitting attack, where this surface can be obtained via electropolishing performed for an optimum time. The effect of electropolishing on the chromium content at the surface and its relation to the corrosion properties were also discussed.
EN
3D printing technology is currently used in various fields. Precision is also becoming more important as the usage of the 3D printing increases. However, the precision of the 3D printing is still low due to limitations of manufacturing methods. Especially, the surface roughness and quality are inconsistent. While the post-treatment is necessary, there are no systematic post-treatment methods. Thus, using the laser for the post-treatment of 3D printing would be a good option because it has many advantages for precision engineering. To be used for the post-treatment process, it is essential to understand the interaction characteristics between the laser and the 3D printing materials. Therefore, this study uses an UV pulsed laser and the acrylonitrile butadiene styrene (ABS), which is the most popular material for 3D printing, to understand the interaction characteristics. Furthermore, the effect of surface roughness on the interaction characteristics is also studied. The ABS specimens are prepared by an acetone fumigation technique and CNC milling. The laser is applied by varing laser pulse energy (50–340 μJ) on the ABS specimens. As the surface roughness decreases, it is confirmed that laser and ABS interaction have a certain pattern. For the specimen prepared by the acetone fumigation technique, Heat Affected Zone decreases with decreasing the laser pulse energy. The specimen prepared by end milling requires higher laser ablation threshold.
EN
The hydraulic support column of comprehensive mining equipment is the most important part, subjecting to corrosion, wear and collision. The scrapped columns are restored by laser cladding to replace plating process for enhancing service life. All that is required after laser cladding is subtractive machining to improve the surface quality of the laser cladded coatings. This work focused on the remanufacturing machining strategy for re-contouring the laser cladding restored columns. First, surface roughness model of the laser cladded coatings by turn-burnishing was presented based on the surface generation mechanism. Then the effect of turning-induced roughness level on the surface roughness improvements by subsequent burnishing is addressed. Results indicated that the reduction of surface roughness by burnishing showed positive correlation with the feed in initial turning with conventional inserts, while was negatively correlated with the feed in initial turning with wiper inserts. In addition, the initial turning-induced surface roughness level generated great influence on the residual stress improvement in subsequent burnishing. Based on the findings, proper remanufacturing machining strategies for re-contouring the laser cladding-restored hydraulic support columns were presented.
EN
In this study, two techniques such as laser surface melting (LSM) and laser surface alloying (LSA) were performed to protect the surface layers of nodular cast iron as it is used to manufacture different machine parts like cams, beds, camshafts, crankshafts, cylinders and engine blocks. The main objective of this research work is to examine the effects of LSM and LSA processes on phases, microstructure, hardness, wear resistance and surface roughness. The outcomes of both LSM and LSA specimens show a homogeneous structure, effective bonding of alloy powders with the base metal and crack-free surfaces. The hardness was improved 4 times (LSM) and 2.62 times (LSA) when compared with the base material. The tribological test shows improved wear resistance of LSM (8.82 × 10−7 kN) and LSA (1.32 × 10−6 kN) samples compared to the base material (4.36 × 10−6 kN). The examined wear tracks indicate that mild abrasion, adhesion and delamination were the major wear mechanisms. The reason for the enhancement of wear resistance is the refinement of microstructure, the solid solution strengthening effect and good bonding between alloy powders and base material. The LSM technique is a potential method to improve the tribological properties of industrial materials.
first rewind previous Strona / 29 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.