Wyniki wyszukiwania - BazTech

1

The Effect of Cutting Tool Wear on the Rate of Corrosion Wear of a Machined Material

Bezjazychnyi Vyacheslav F., Pleskun Vladislav V.

Tribologia

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2020

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nr 1

5--11

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).

2

The possibilities to reduce surface roughness in pre-assembly face milling with Wiper inserts

Frączyk Adam

Technologia i Automatyzacja Montażu

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2020

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nr 1

52--56

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.

3

Analysis of the impact of surface roughness on the capacity of adhesive joints from aluminum alloy 2024

Bąk Łukasz, Guźla Ewelina, Łyko Michał

Technologia i Automatyzacja Montażu

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2020

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nr 2

27--33

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.

4

Analysis of the impact of surface roughness on the bearing capacity of lap adhesive joints from aluminum alloy 2024

Zielecki Władysław, Dzierwa Andrzej, Guźla Ewelina

Technologia i Automatyzacja Montażu

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2020

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nr 3

15--21

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.

5

Analysis of the grinding force components and surface roughness in grinding with the use of a glass-crystalline bonded grinding wheel

Żółkoś Marcin

Technologia i Automatyzacja Montażu

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2020

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nr 1

44--51

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.

6

Surface treatment of incrementally produced components in FFF (Fused Filament Fabrication) technology

Mrówka Maciej, Machoczek Tomasz, Szymiczek Małgorzata, Gągol Przemysław, Duda Sławomir, Marcoll Łukasz

Polimery

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2020

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T. 65, nr 1

51--59

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.

7

Optimum combination of machining parameters during drilling of aluminium 7075 alloys using Grey based Taguchi approach

Sreenivasulu Reddy, Rao Chalamalasetti Srinivasa

Journal of Mechanical and Energy Engineering

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2020

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Vol. 4, No 3

227--238

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.

8

Optimization of machining parameters during end milling of super alloys using grey based Taguchi method coupled with entropy measurement technique

Sreenivasulu Reddy, Rao Chalamalasetti Srinivasa

Journal of Mechanical and Energy Engineering

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2020

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Vol. 4, No 1

47--56

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.

9

Study on the use of Aerogel on the Surface of Basalt Fabric

Miśkiewicz Pamela, Frydrych Iwona, Tokarska Magdalena

Autex Research Journal

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2020

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Vol. 20, no. 2

168--177

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.

10

Research on the Influence of Vibratory Machining on Titanium Alloys Properties

Bańkowski D., Spadło S.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 3

47--52

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.

11

Unraveling the effects of surface preparation on the pitting corrosion resistance of austenitic stainless steel

Sohrabi M. J., Mirzadeh H., Dehghanian C.

Archives of Civil and Mechanical Engineering

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2020

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Vol. 20, no. 1

99--108

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.

12

Comparative study of laser melting and pre‑placed Ni–20% Cr alloying over nodular iron surface

Jeyaprakash N., Yang Che-Hua, Duraiselvam Muthukannan, Sivasankaran S.

Archives of Civil and Mechanical Engineering

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2020

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Vol. 20, no. 1

282--293

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.

13

Ridge geometry effect on the behavior of elastohydrodynamic lubrication of point contact problem

Al-Samieh Mohamed F. Abd

Archive of Mechanical Engineering

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2020

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LXVII, nr 4

491--508

EN

A numerical solution is presented to investigate the influence of the geometry and the amplitude of the transverse ridge on the characteristics of elastohydrodynamic lubrication for point contact problem under steady state condition. Several shapes of ridges with different amplitudes are used in the stationary case, such as flat-top ridge, cosine wave ridge and sharp ridge of triangular shape. Results of film thickness and pressure distributions of the aforementioned ridge feature are presented at different locations through an elastohydrodynamically lubricated contact zone for different amplitude of the ridge. Simulations were performed using the Newton-Raphson iteration technique to solve the Reynolds equation. The numerical results reveal that, to predict optimum solution for lubricated contact problem with artificial surface roughness, the geometrical characteristics of the ridge should have profiles with smooth transitions such as those of a cosine wave shape with relatively low amplitude to reduce pressure spike and therefore cause the reduction in the film thickness. The position of the location of the ridge across the contact zone and the amplitude of the ridge play an important role in the formation of lubricant film thickness and therefore determine the pressure distribution through the contact zone.

14

Predictive modeling and machining performance optimization during drilling of polymer nanocomposites reinforced by graphene oxide/carbon fiber

Kumar Jogendra, Verma Rajesh Kumar, Mondal Arpan Kumar

Archive of Mechanical Engineering

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2020

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LXVII, nr 2

229--258

EN

This paper explores the parametric appraisal and machining performance optimization during drilling of polymer nanocomposites reinforced by graphene oxide/-carbon fiber. The consequences of drilling parameters like cutting velocity, feed, and weight % of graphene oxide on machining responses, namely surface roughness, thrust force, torque, delamination (In/Out) has been investigated. An integrated approach of a Combined Quality Loss concept, Weighted Principal Component Analysis (WPCA), and Taguchi theory is proposed for the evaluation of drilling efficiency. Response surface methodology was employed for drilling of samples using the titanium aluminum nitride tool. WPCA is used for aggregation of multi-response into a single objective function. Analysis of variance reveals that cutting velocity is the most influential factor trailed by feed and weight % of graphene oxide. The proposed approach predicts the outcomes of the developed model for an optimal set of parameters. It has been validated by a confirmatory test, which shows a satisfactory agreement with the actual data. The lower feed plays a vital role in surface finishing. At lower feed, the development of the defect and cracks are found less with an improved surface finish. The proposed module demonstrates the feasibility of controlling quality and productivity factors.

15

The Influence of Technological Factors on the Strength of Adhesive Joints of Steel Sheets

Doluk Elżbieta, Rudawska Anna, Brunella Valentina

Advances in Science and Technology. Research Journal

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2020

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Vol. 14, no 1

107--115

EN

The paper evaluates the effect of the surface treatment on the strength of the single‑lap adhesive joints made of the C45 steel. The samples were joined using an adhesive composition consisting of Epidian 57 epoxy resin and PAC curing agent. The study also used Greinplast mosaic plaster with a grain size of 1.0–1.6 mm as coating. The experiment was carried out for 3 variants of joints: sheet/sheet, sheet+plaster/sheet+plaster, sheet/sheet+plaster. Each variant was divided into 3 methods of surface treatment. The strength tests were carried out on the Zwick/Roell Z150 testing machine. The roughness parameters of the surface’s samples were measured using a HOMMEL TESTER T1000 profilometer.

16

Prediction of Surface Roughness based on the Machining Conditions with the Effect of Machining Stability

Lin Yung-Chih, Chen You-Chen, Wu Kung-Da, Hung Jui-Pin

Advances in Science and Technology. Research Journal

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2020

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Vol. 14, no 2

171--183

EN

This study was aimed at analyzing the influence of the cutting parameters (spindle speed, feed rate and cutting depth) on the surface roughness of the machined parts with the influence of the machining stability of the cutter. In order to consider the chattering effect, the machining stabilities were calculated based on the measured tool tip frequency response functions. A series of machining tests were conducted on aluminum workpieces under different cutting parameters. Then, the surface roughness prediction models in the form of nonlinear quadratic and power-law functions were established based on the multivariable regression method, in which the input parameters, cutting depth and spindle speed, were respectively defined in the stable and unstable regions, according to the stability lobes diagram. The current results show that both models built with the cutting parameters defined in stable regions demonstrate higher prediction accuracy of the surface roughness, about 90%, when compared with the models defined in full regions with the accuracy of about 80%. In particular, the power-law model is proven to have 90% prediction accuracy when validated with the cutting parameters in a stable region. As a conclusion, the mathematical models based on the cutting parameters with well-defined machining stability were proven to show more accurate prediction ability of the surface roughness. It could be expected that the prediction model can further be applied to optimize the machining conditions in low speed roughing and high speed finishing process with desirable surface quality.

17

Influence of the Length of Components from Polymer Composite on Selected Machinability Indicators in the Circumferential Milling Process

Ciecieląg Krzysztof

Advances in Science and Technology. Research Journal

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2020

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Vol. 14, no 4

229--239

EN

The article presents the results of the research on the influence of the length of elements made of carbon fiber reinforced plastics (CFRP) and glass fiber reinforced plastics (GFRP) on surface roughness, surface topography, passive forces and cutting torques after circumferential milling with diamond-coated inserts (PCD). The paper also presents the results of the research on the stiffness of the elements depending on their length. The samples of composite materials were clamped in a vise at the machining center. The length of the element was defined as the unsupported distance between the milled surface and the place of attachment of the composite element. With constant milling parameters, the maximum values and amplitudes of the values of passive forces and cutting torques at variable element lengths were determined. The obtained surface was measured in order to determine the surface roughness parameters and 3D topography. The research showed that the carbon fiber reinforced plastics is on average one and a half times stiffer than that the glass fiber reinforced plastics. On the basis of the results obtained, it was found that the passive forces and cutting torques as well as the roughness parameters increase along with the length of the element. It was also shown that for the glass fiber reinforced plastics, above a certain length, the surface roughness clearly deteriorates.

18

Effectiveness of Diamond Blades in the Turning of Aluminium Composites

Karolczak Paweł, Kołodziej Marek, Kowalski Maciej

Advances in Science and Technology. Research Journal

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2020

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Vol. 14, no 4

262--272

EN

Owing to their excellent strength-to-weight ratio aluminium composite materials are very readily used in the construction of means of transport. The parts made of such materials must be characterized by high reliability and workmanship. Hence, machining is the predominant method of manufacturing parts from composites. The problem with the turning, milling and drilling of ceramic-reinforced composites is the abrasive action of the reinforcement, resulting in heavy wear of the blades and so in lower surface quality and dimensional-shape accuracy and higher manufacturing costs. A solution to this problem can involve the blades made of superhard materials or properly matched conditions of machining with sintered carbide blades. This paper presents the results of the turning tests carried out on an aluminium composite material reinforced with long ceramic fibres. An uncoated sintered carbide blade is compared with a diamond coated blade and a polycrystalline diamond blade. Post-turning surface roughness and machining forces were selected as the main indicators of cutting ability. The effect of the blades on the forming chips is shown and the higher resistance of the polycrystalline diamond blades to the abrasive action of the reinforcing fibres is confirmed by microscopic photographs. Besides the confirmation of the higher durability of the diamond blades, the conditions in which when using these blades one can achieve better machining effects than the ones achievable by the compared tools are defined. Moreover, it is shown that by properly matching the machining parameters and aiding machining with oil mist lubrication, it is possible to obtain excellent surface quality by means of carbide blades. The minimum quantity lubrication also increases the life of the blades.

19

Control of kinetics of plasma assisted nitriding process of Ni-base alloys by substrate roughness

Nowak Wojciech J.

Advances in Manufacturing Science and Technology

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2020

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Vol. 44, nr 3

99-108

EN

The present study investigated the effect of surface roughness on plasma assisted nitriding (PAN) process kinetics of Ni-base alloys. Two model alloys, namely Ni-10Cr and Ni-14Cr-4Al (wt.%) and commercial Rene 80, were examined. To elucidate the effect of surface roughness on nitriding kinetics, three methods of surface preparation were used, (1) polishing up with 1 μm diamond suspension, (2) grinding up to 220 grit sand-paper, and (3) grit blasting. The samples from each type of material were nitrided under the same conditions and investigated after processing. It was found that increase in roughness results in decreasing nitriding kinetics. The decrease of nitriding kinetics depends on alloy chemical composition, namely more complex chemistry resulted in smaller decrease of kinetics. Moreover, grit-blasting was found to be an improper method for surface preparation for PAN. The responsible mechanism for the effect of surface roughness on PAN kinetics of Ni-base alloys was proposed.

20

Analiza nowych konstrukcji segmentowych tarcz ściernych przeznaczonych do szlifowania granitu

Rajczyk Paweł

Zarządzanie Przedsiębiorstwem

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2019

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Vol. 22, nr 2

22--28

EN

The purpose of the work is to develop a new effective construction and material for the granite abrasive grinding wheel. The task was undertaken in order to shorten the time of surface grinding machining operations by providing for a given cycle a homogeneous postprocessing surface of high quality, shortening the time for a given group of granularity of abrasive segments. For the purpose of the work, an analysis of the effectiveness of the working surface of the disc’s surface of known geometric solutions and a new disc geometry solution was carried out. The recipes of the material composition and the technology of making prototypes of discs with new geometry of abrasive segments for which laboratory tests were carried out were developed. The evaluation of the effectiveness of their work for the production conditions has been tested in laboratory conditions, where discs with a diameter of 100 mm were tested operating at constant kinematic parameters ω = 960 rpm and at a constant pressure of the 20 N disc to the surface to be machined. Effectiveness of the impact was verified by the distribution of surface roughness on the treatment floor of the width corresponding to the diameter of the disc left on the surface of the granite slab. Initial tests were carried out on the author’s stand, ensuring: rotational speed measurement, constant pressure of the disc to the material being processed, surface roughness measurement after each of the three cycles of the disc impact using the Mitutoyo roughness tester.