Wyniki wyszukiwania - BazTech

1

A comprehensive review of polymer materials and selective laser sintering technology for 3D printing

Jabri F. E., Ouballouch A., Lasri L., Alaiji R. El

Journal of Achievements in Materials and Manufacturing Engineering

|

2023

|

Vol. 118, nr 1

5--17

EN

Purpose This review analyses different approaches used to study selective laser sintering (SLS) technology of polymer materials. These main approaches concern: thermal behaviour, fatigue and surface roughness. Design/methodology/approach Regarding the first behaviour, researchers extensively studied the impact of process parameters, including scan speed, laser, power and laser energy density, on the thermal behaviour of 3D printed parts. Numerical and experimental analyses are used to conduct process parameter evaluations. Findings Laser power and scan speed are the most significant parameters of the laser energy density. For the second, according to test protocols and quantitative analysis performed, the authors concluded that the combination of small and large laser energy density particles generates higher sintering and better fatigue resistance. Moreover, tensile analysis in different environments showed that testing in the water decreased the fatigue life of polymer samples. The influence of process parameters on the mechanical properties and surface roughness of 3D parts is also analysed. In addition, the investigators found that the additives increase the surface roughness of 3D printed parts. Practical implications This review shows that researchers can focus on creating a combination of these approaches to expand the use of this process for industrial part production. Originality/value All these investigations have made it possible to determine the optimal process conditions to ensure higher quality, optimal surface quality and better fatigue strength.

2

Analysis and Investigation the Effect of the Printing Parameters on the Mechanical and Physical Properties of PLA Parts Fabricated via FDM Printing

Abdulridha HInd Hadi, Abbas Tahseen Fadhil

Advances in Science and Technology. Research Journal

|

2023

|

Vol. 17, no 6

49--62

EN

Fused deposition modeling (FDM) is a commonly used additive manufacturing (AM) technique that creates prototypes and parts with intricate geometrical designs. It is gaining popularity since it enhances products by removing the need for expensive equipment. The printed item's mechanical properties are affected by the type of materials used, the printing process, and the printing parameters. The 3-D model of the polylactic acid (PLA) filament generated specimens was created using the Fused Deposition Modeling procedure and developed using Solid Works. This study investigates the effect of printing parameters on the mechanical and physical properties of samples printed using a Fused Deposition Modeling machine (Creality Ender-5 Pro). Six parameters are used: infill pattern, density, overlap percentage, layer thickness, shell thickness, and top/bottom layer number. Five levels were chosen for each FDM parameter. The results illustrated how printing parameters affected the mechanical and physical properties of samples, which were proven by ultimate tensile stress, surface roughness, and percentage of tensile average deviation. A comparison between the predicted results and the measured results was presented, and the maximum percentage error of the model, which fit the data well, was 0.54%, 0.3%, and 1.36% for ultimate tensile strength (UTS), surface roughness (Ra), and Tensile average deviation percentage respectively.

3

Effect of parameters of the stereolithography process on the part quality

Lewiński Tomasz, Kukiełka Krzysztof, Chaciński Tomasz, Jaskólski Piotr

Journal of Mechanical and Energy Engineering

|

2022

|

Vol. 6, No 2

1--12

EN

This paper investigates the effect of additive manufacturing parameters on the manufacturing quality of selected gear mechanism components. Three input variables, and two output variables were determined. The result was the determination of the most optimal combination of key parameters and the determination of regression equations. The concept of manufacturing objects of a very complex shape, by any person, under various conditions through the use of a low-cost device became the basis for this thesis topic. Curing time, layer thickness, and lift speed are among the basic parameters, with a large range of manipulation. A hypothesis was formulated that these three parameters are crucial to produce a part with the smallest possible deviations from the computer model. A handheld scanner was used to scan the samples and compare them with the CAD model. Based on the study, optimal parameters for layer thickness, curing time and lift speed were proposed.

4

Extended friction stir welding applications and the use of an innovative FSW head

Nowak Mirosław, Szostek Paweł, Nowak Marcin

Biuletyn Instytutu Spawalnictwa w Gliwicach

|

2022

|

Vol. 66, No. 5

61--72

EN

The article presents general information about friction stir welding process (FSW) as a welding method involving the stirring of the weld material, discusses the course of the welding process itself, describes the structure of the FSW joint, presents advantages and disadvantages of the method as well as discusses factors affecting the quality of FSW joints. In addition, the article describes an innovative FSW head (designed by Stirweld (France) and installed on CNC machines) as well as illustrates the operation of the head and enumerates the advantages resulting from the use of the head in comparison with those characteristic of “conventional” friction stir welding machines.

PL

W artykule przedstawiono ogólne informacje na temat metody zgrzewania z mieszaniem materiału zgrzeiny FSW (Friction Stir Welding). Scharakteryzowano przebieg procesu zgrzewania, opisano budowę złącza, przedstawiono i omówiono wady oraz zalety metody, a także czynniki wpływające na jakość połączeń. W publikacji opisano innowacyjną głowicę do zgrzewania FSW firmy Stirweld (Francja), instalowaną na frezarkach CNC. Zilustrowano proces działania głowicy oraz omówiono korzyści wynikające z jej zastosowania w porównaniu ze zgrzewarkami FSW.

5

Parametric Analysis on the Progression of Mechanical Properties on FSW of Aluminum-Copper Plates

Deepati Anil Kumar, Alhazmi Waleed, Zakri Waleed, Shaban Essam, Biswas Pankaj

Advances in Science and Technology. Research Journal

|

2022

|

Vol. 16, no 2

168--178

EN

The contemporary work manifests that friction stir welding (FSW) is a viable avenue for joining AA1100 aluminium (Al) to C12200 copper (Cu) plates. In this present study, the response of distinctive welding parameters (viz. tool geometries, tool rotational speed, tool travel speed, and tool plunging depth) on weld quality has been investigated. The present work focused on both microstructural investigation and mechanical properties examination. It has been observed that the process parameters have significant effects on weld quality. The design of the experiments has been executed considering four welding input parameters in two variables and selected L-16 orthogonal array to limit the experimental replications. It has been observed that good quality of welds produced by keeping the tool pin offset around 4mm towards the aluminium side and 2mm towards the copper side. And it has also been noticed that right-hand threaded tool pins are giving good weld quality compared to left-handed thread. The joint efficiencies for the welds E2, E14 which were welded by RHT tools were 75.3% and 74.61% and the Strength (UTS) of the welds for the same tools exhibit’s greater than the LHT tools i.e., 98 and 95Mpa. Moderate hardness values are observed for the same welds E1 and E14 with the parameters 1100rpm, 98welding speed, and 1.6mm tool plunge depth. . It also noticed that the weld quality can be significantly enhanced by using proper tool plunge and tool pin geometries compared to the other process parameters.

6

Influence of mold design and injection parameters on warpage deformation of thin-walled plastic parts

Wang Bo, Cai Anjiang

Polimery

|

2021

|

T. 66, nr 5

283--292

EN

Thin-walled plastic parts are susceptible to deformation during injection molding. Using the example of a notebook battery cover, optimization of the injection mold design and injection process parameters was performed with Moldflow software, which resulted in about 69% reduction of the deformations. Moreover, the uneven material shrinkage during the injection process has been shown to be the main cause of deformations of thin-walled plastic parts.

PL

Cienkościenne elementy z tworzyw polimerowych są podatne na odkształcenia podczas formowania metodą wtryskiwania. Na przykładzie pokrywy baterii notebooka dokonano optymalizacji konstrukcji formy wtryskowej oraz parametrów procesu wtrysku w programie Moldflow, co pozwoliło na zmniejszenie odkształceń o około 69%. Ponadto wykazano, że nierównomierny skurcz materiału podczas procesu wtryskiwania jest główną przyczyną deformacji cienkościennych elementów z tworzyw polimerowych.

7

Influence of FFF process parameters and macrostructure homogeneity on PLA impact strength

Bączkowski Michał, Marciniak Dawid, Bieliński Marek

Polimery

|

2021

|

T. 66, nr 9

480--483

EN

The article presents studies of the additive manufacturing printing parameters influence on the impact strength of PLA samples obtained by the fused filament fabrication (FFF) method. Two process variables were taken into account in the research program: the height of the printed layer and the printing temperature. An optical microscope was used to analyze the cross-section image (breakthrough) of the samples. The impact strength was determined at −40°C and 23°C. Selected geometric features of the macrostructure (uniformity and thickness of individual layers, voids) determined on the basis of the sample cross-section image analysis, enhanced the possibility of assessing the PLA impact strength, depending on the adopted process variables and the temperature at which the experiment was carried out.

PL

W artykule przedstawiono badania wpływu parametrów druku addytywnego na udarność próbek z PLA otrzymanych metodą FFF (fused filament fabrication). W programie badań uwzględniono dwie zmienne procesowe: wysokość drukowanej warstwy i temperaturę druku. Do analizy obrazu przełomu próbek wykorzystano mikroskop optyczny. Oznaczono udarność w temperaturze -40°C oraz 23°C. Wybrane cechy geometryczne makrostruktury (równomierność i grubość poszczególnych warstw, puste przestrzenie) wyznaczone na podstawie analizy obrazu przekroju próbek, pogłębiły możliwość oceny udarności PLA w zależności od przyjętych zmiennych procesowych, a także temperatury w jakiej zrealizowano eksperyment.

8

Experimental modeling of the milling process of aluminum alloys used in the aerospace industry

Țîțu Aurel Mihail, Pop Alina Bianca, Nabiałek Marcin, Dragomir Camelia Cristina, Sandu Andrei Victor

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2021

|

Vol. 69, nr 5

art. no. e138565

EN

This research presents an experimental study carried out for the modeling and optimization of some technological parameters for the machining of metallic materials. Certain controllable factors were analyzed such as cutting speed, depth of cut, and feed per tooth. A dedicated research methodology was used to obtain a model which subsequently led to a process optimization by performing a required number of experiments utilizing the Minitab software application. The methodology was followed, and the optimal value of the surface roughness was obtained by the milling process for an aluminum alloy type 7136-T76511. A SECO cutting tool was used, which is standard in aluminum machining by milling. Experiments led to defining a cutting regime that was optimal and which shows that the cutting speed has a significant influence on the quality of the machined surface and the depth of cut and feed per tooth has a relatively small impact on the chosen ranges of process parameters.

9

Multi-objective optimization of process parameters in cold forging minimizing risk of crack and forging energy

Kitayama Satoshi, Kadoya Shimon, Takano Masahiro, Kobayashi Akio

Archives of Civil and Mechanical Engineering

|

2021

|

Vol. 21, no. 3

795--806

EN

In this paper, a typical cold forging process using spring-held die is considered, in which the process parameters such as stiffness of spring, the initial loads and the punch speed are conventionally adjusted by the trial-and-error method for high product quality. The target product has the earing, around which the crack is often observed by the conventional process parameters. To avoid the crack around the earing, the process parameters optimization is performed through numerical simulation using DEFORM3D, in which two objective functions are considered. The risk of crack is numerically evaluated and is minimized, whereas the total forging energy using the load-stroke diagram is also minimized. Therefore, the multi-objective design optimization is performed. The numerical simulation is so intensive that sequential approximate optimization using radial basis function network is adopted to identify the pareto-frontier between the objectives with a small number of simulations. Compared with the product using the conventional process parameters, the optimal process parameters can reduce both the risk of crack and the total forging energy. In addition, the flow lines along the product shape can be obtained by using the optimal process parameters. Based on the numerical result, the experiment using the mechanical press (IST100W, ITO) is carried out. No crack is observed in the experiment, and then the validity of the proposed approach is confirmed.

10

Research of the Tool Velocity and Product Shape Aspects of the Hot Radial Rolling of C45 Steel Rings

Surdacki Piotr, Gontarz Andrzej, Winiarski Grzegorz, Samołyk Grzegorz

Advances in Science and Technology. Research Journal

|

2021

|

Vol. 15, no 4

352--363

EN

The control of product shape and dimensions poses some problems in hot ring rolling. In the rolling process, material flows both circumferentially and axially, which leads to increased ring height. Changes in shape and dimensions of ring cross section depend on several process parameters, which makes it difficult to predict ring diameter. This paper presents the results of a study investigating the hot radial rolling process for C45 steel rings in terms of the effect of main roll feed speed on product geometry. It was found that the application of a higher feed speed of the main roll and thus of a greater ratio between this speed and circumferential speed of the main roll led to increased axial material flow and reduced cross-sectional defect known as ”fishtail”. Machining losses generated due to cross-sectional defects were also determined. Results were used to determine the feed speed to circumferential speed ratio ensuring the lowest possible cross-sectional defect and material consumption.

11

Zastosowanie pakietu programów CHEMCAD do projektowania i optymalizacji instalacji oczyszczania etanolu

Krzywda Roman, Gierycz Paweł

Przemysł Chemiczny

|

2020

|

T. 99, nr 3

406--411

PL

Pakiet programów CHEMCAD zastosowano do zaprojektowania linii oczyszczania etanolu. Jej głównymi aparatami były wyparka oraz kolumna rektyfikacyjna. Obliczenia przeprowadzono dla instalacji otrzymywania alkoholu etylowego o zadanym stężeniu. Proces technologiczny polegał na wprowadzeniu surówki zawierającej wodę, etanol oraz związki chemiczne o małej prężności pary nasyconej w warunkach normalnych do wyparki pracującej pod obniżonym ciśnieniem, w której następowało oddestylowanie etanolu i części wody (para). Opary z wyparki były następnie sprężane do ciśnienia atmosferycznego i kierowane do chłodnicy, w której następowało ich schłodzenie i skroplenie. Otrzymaną w ten sposób ciekłą mieszaninę kierowano do kolumny rektyfikacyjnej pracującej pod normalnym ciśnieniem, w której następowało rozdzielenie mieszaniny na etanol (o odpowiednim stężeniu) i wodę (zawierającą alkohol etylowy o małym stężeniu). Tak zaprojektowana instalacja została następnie zoptymalizowana (dwa warianty) ze względu na oszczędność energii. Otrzymano szczegółowe dane dotyczące wielkości, składu i parametrów strumieni w badanych instalacjach (3 linie produkcyjne) oraz nakładów energetycznych koniecznych do poniesienia w każdej z nich. Badania pokazały duże możliwości obliczeniowe i optymalizacyjne programu CHEMCAD.

EN

A plant for the sepn. of EtOH (90% purity) from its. aq. soln. was designed. The plant consisted of an evaporator and a rectification column. The feed stream contained H₂O, EtOH as well as non-volatile and low-volatile chem. compds. The non-random two-liqs. (NRTL) equation was used to describe the EtOH-H₂O equil. The whole technol. process was based on the assumption that the feed stream was directed into evaporator under reduced pressure, where EtOH and some H₂O were distilled off. The vapors were compressed to the ambient pressure, condensed and directed to the rectification column. The design was optimized for energy consumption.

12

A Statistical Analysis of Evaporative Pattern Casting Process Parameters for the Production of Aluminum Alloy Components

Omidiji Babatunde Victor

Journal of Casting & Materials Engineering

|

2020

|

Vol. 4, no. 3

41--47

EN

Four process parameters were investigated with the aim of determining their influence on the mechanical properties of some test castings, bars, cylinders and plates. The influence was quantified in terms of percentage contribution. Analysis of variance (ANOVA), regression, main effects and interaction effects plots were employed to carry out the statistical analysis. As regards the tensile strength of the test castings, the geometry of components (GOC) dominated, contributing 90.83% and the pouring temperature (PT) contributed 91.90% influence on the hardness property. These dominating potentials of these two parameters limited the interaction of the parameters studied in the research. statistical analysis. As regards the tensile strength of the test castings, the geometry of components (GOC) dominated, contributing 90.83% and the pouring temperature (PT) contributed 91.90% influence on the hardness property. These dominating potentials of these two parameters limited the interaction of the parameters studied in the research.

13

Makroskopowy model gładzenia cylindrów silników spalinowych jako narzędzie optymalizujące wysokość osełek gładzarskich w technologii napraw

Michalski J., Domański J.

Autobusy : technika, eksploatacja, systemy transportowe

|

2018

|

R. 19, nr 6

600--608, CD

PL

W artykule przedstawiono założenia makroskopowego modelu matematycznego gładzenia uwzględniające zarówno kinematykę narzędzia jak również charakterystyczny dla tego procesu rozkład nacisków jednostkowych występujących w oddziaływaniu osełek gładzących na powierzchnię obrabianego cylindra. Na bazie opisanych złożeń został opracowany działający i przetestowany program komputerowy, który w sposób numeryczny modeluje ten proces technologiczny. W pamięci komputera są tworzone cyfrowe mapy jakościowe dotyczące powierzchni zarówno cylindra i osełek gładzących. Mapy te można oceniać analitycznie jak również poddać wizualizacji. W artykule zamieszczono wyniki obliczeń optymalizujących wysokość osełek gładzarskich dla procesu gładzenia konkretnej tulei cylindrowej wraz z analizą otrzymanych wyników. Opisany program komputerowy umożliwia oszczędność czasu oraz środków finansowych w czasie dedykowanych badań optymalizujących parametry tego procesu.

EN

The paper presents the assumptions of the macroscopic mathematical model of honing, taking into account both the kinematics of the tool and the characteristic for this process the distribution of unit pressures occurring in the interaction of sharpening stones on the surface of the honing stones on the surface of the workpiece are characteristic for this process. On the basis of these assemblies an active and tested computer program has been developed, which numerically model this technological process. In the computer memory are created digital quality maps of the surface of the machined cylinder. On the basis of the described assemblies, a working and tested computer program has been developed that numerically models this technological process. Digital quality maps are created in the computer's memory regarding the surface of both the cylinder and the smoothing stones. These maps can be assessed analytically as well as subjected to visualization. The article presents the results of calculations that optimize the height of smooth ground for the process of honing a specific cylinder liner with the analysis of the results obtained. The described computer program saves time and funds during dedicated research that optimizes the parameters of this process.

14

Optimization and analysis of porosity and roughness in selective laser melting 316L parts

Król M., Mazurkiewicz J., Żołnierczyk S.

Archives of Materials Science and Engineering

|

2018

|

Vol. 90, nr 1

5--15

EN

Purpose: The investigations have been carried out on 316L stainless steel parts fabricated by Selective Laser Melting (SLM) technique. The study aimed to determine the effect of SLM parameters on porosity, hardness, and structure of 316L stainless steel. Design/methodology/approach: The analyses were conducted on 316L stainless steel parts by using AM125 SLM machine by Renishaw. The effects of the different manufacturing process parameters as power output, laser distance between the point’s melted metal powder during additive manufacturing as well as the orientation of the model relative to the laser beam and substrate on porosity, hardness, microstructure and roughness were analysed and optimised. Findings: The surface quality parts using 316L steel with the assumed parameters of the experiment depends on the process parameters used during the SLM technique as well as the orientation of formed walls of the model relative to the substrate and thus the laser beam. The lowest roughness of 316L SLM parts oriented perpendicularly to the substrate was found when 100 W and 20 μm the distance point was utilised. The lowest roughness for part oriented at 60° relatives to the substrate was observed when 125 W and the point distance 50 μm was employed. Practical implications: Stainless steel is one of the most popular materials used for selective laser sintering (SLM) processing to produce nearly fully dense components from 3D CAD models. Reduction of porosity is one of the critical research issues within the additive manufacturing technique SLM, since one of the major cost factors is the post-processing. Originality/value: This manuscript can serve as an aid in understanding the importance of technological parameters on quality and porosity of manufactured AM parts made by SLM technique.

15

Determination of Duration and Sequence of Vacuum Pressure Saturation in Infiltrated MMC Castings

Gawdzińska K., Nagolska D., Szymański P.

Archives of Foundry Engineering

|

2018

|

Vol. 18, iss. 1

23--28

EN

The paper presents a detailed description of one of the newest methods of vacuum saturation of reinforcing preforms in gypsum molds. As an appropriate selection of the infiltration time is a crucial problem during realization of this process, aim of the analysis shown in the paper is to present methods of selection of subatmospheric pressure application time, a sequence of lowering and increasing pressure, as well as examining influence of structure of reinforcing preforms on efficiency of this process. To realize the aim, studies on infiltration of reinforcing preforms made of a corundum sinter of various granulation of sintered particles with a model alloy were conducted. The infiltration process analysis was carried out in two stages. The first stage consisted in investigation of influence of lengthening of sucking off air from the reinforcing preforms on efficiency of this process. In the second stage, an analysis of influence of a two-staged infiltration process on saturation of the studied materials was conducted. Because the studied preforms were of similar porosity, the obtained differences of the saturation level of particular preforms have shown, that the saturation process is influenced mostly by size of pores present in the reinforcement. Because of these differences, each reinforcement type requires individual selection of time and sequence of the saturation process. For reinforcements of higher pore diameter, it is sufficient to simply increase air sucking off time to improve the saturation, while for reinforcement of smaller pore diameter, it is a better solution to apply the two-staged process of sucking off air. Application of the proposed analysis method allows not only obtaining composite castings of higher quality, but also economical optimization of the whole process.

16

The effect of RFSSW parameters on the load bearing capacity of aluminum 7075-T6 sheet metal joints

Kluz Rafał, Kubit Andrzej, Wydrzyński Dawid

Advances in Science and Technology. Research Journal

|

2018

|

Vol. 12, no 2

35--41

EN

Friction Stir Spot Welding is one of the most contemporary methods of joining metals and alloys in their solid state. The ability to join elements made of aluminum alloys allows for utilizing this method in the manufacturing of aircraft structures while lowering the work load, costs, and weight, without sacrificing or even having better strength parameters than classic methods of joining elements. It ensures constant joint parameters, however it requires the use of optimal welding parameters such as: the rotational speed of the tool, tool delve depth, and welding time. The work presents the results of experiments conducted on 7074 aluminum sheet metal that was 1.8 and 0.8 mm thick, which conducted in accordance with the PS/DK32 research plan. The welding tests were done on a dedicated spot welding machine, while the strength tests consisted of static tensile strength tests. In the final part of the article contains an analysis and interpretation of the results.

17

Zgrzewanie punktowe blach ze stopu aluminium 7075-T6

Kluz R., Kubit A., Wydrzyński D.

Technologia i Automatyzacja Montażu

|

2017

|

nr 2

56--60

PL

Punktowe zgrzewanie tarciowe z przemieszaniem jest jedną z najnowocześniejszych metod łączenia metali i ich stopów w stanie stałym. Możliwość łączenia elementów wykonanych ze stopów aluminium pozwala na stosowanie tej metody przy produkcji struktur lotniczych, przy jednoczesnym obniżeniu pracochłonności, kosztów i ich ciężaru, zachowując porównywalne lub wyższe parametry wytrzymałościowe w porównaniu do klasycznych metod łączenia elementów. Zapewnienie stałości parametrów użytkowych połączeń wymaga jednak doboru parametrów procesu zgrzewania, tj.: prędkości obrotowej narzędzia, zagłębienia narzędzia oraz czasu zgrzewania. W pracy zaprezentowano wyniki badań procesu zgrzewania blach aluminiowych 7075-T6 o grubości 1,8 i 0,8 mm. Testy zgrzewania przeprowadzono na dedykowanej maszynie do zgrzewania punktowego, natomiast badania wytrzymałościowe obejmowały statyczną próbę ścinania. W końcowej części artykułu dokonano analizy porównawczej nośności połączenia i budowy spoiny uzyskanej metodą RFSSW przy najkorzystniejszych parametrach ze zgrzeiną wykonaną metodą zgrzewania oporowego.

EN

Friction Stir Spot Welding is one of the most contemporary methods of joining metals and alloys in their solid state. The ability to join elements made of aluminum alloys allows for utilizing this method in the manufacturing of aircraft structures while lowering the work load, costs, and weight, without sacrificing or even having better strength parameters than classic methods of joining elements. It ensures constant joint parameters, however it requires the use of optimal welding parameters such as: the rotational speed of the tool, tool delve depth, and welding time. The work presents the results of experiments conducted on 7075-T6 aluminum sheet metal that was 1.8 and 0.8 mm thick. The welding tests were done on a dedicated spot welding machine, while the strength tests consisted of static tensile strength tests. In the final part of the article comparative analysis was made of strength of joint made by RFSSW method and obtained from the resistance welding.

18

Analiza efektywności programowanych strategii frezowania złożonych kieszeni

Deja M., Eremus J., Siemiątkowski M.

Mechanik

|

2017

|

R. 90, nr 10

846--848

PL

Przedstawiono metodę doboru parametrów technologicznych w programowanych strategiach frezowania złożonych kieszeni z wykorzystaniem określonego zestawu narzędziowego. Przeanalizowano wpływ osiowej i promieniowej głębokości skrawania na czas maszynowy realizowanej operacji, co pozwoliło na dobór tych wartości pod kątem maksymalizacji efektywności czasowej wybranej sekwencji narzędziowej.

EN

Presented is a selection method for determining the key process parameters for complex-shape pocket milling strategies using a definite tool set. The analysis concerning the influence of both axial and radial depth of cut on machining operation time was carried out in order to enable the selection of their proper setting values, considering the maximum effectiveness of selected tool sequence mostly in terms of time.

19

Optimization of turning process parameters by Taguchi-based Six Sigma

Das P. P., Gupta P., Ghadai R. K., Ramachandran M., Kalita K.

Mechanics and Mechanical Engineering

|

2017

|

Vol. 21, nr 3

649--656

EN

In this paper, Six Sigma approach is used for improving the quality process outputs in turning of Galvanized Iron. The objective is to optimize the turning parameters and maximize the MRR (Material Removal Rate). A L16 orthogonal array based on Taguchi experiments consisting of three controlling factors viz. spindle speed, feed rate, and depth of cut, each with four levels as required in traditional DOE setting is used here. Taguchi’s parameter design offers an approach in Design of Experiments (DOE) with control parameters optimization to attain best outcome. An orthogonal array offers a set of balanced least experiments which help in data analysis and prediction of optimum results. For each experiment, the Material Removal Rate (MRR) is calculated. The Taguchi method results in reducing the quality characteristic variation due to uncontrollable parameter through the study of response variation using the Signal to Noise (S/N) ratio by the use of Minitab 16 software. Moreover, statistical investigation shows that standard deviation and mean value of confirmation run data are reduced when compare with before Taguchi design run data was performed.

20

Analiza teoretyczna parametrów geometrycznych i prędkościowych w procesie walcowania pierścieni na gorąco

Surdacki P., Gontarz A.

Hutnik, Wiadomości Hutnicze

|

2017

|

Vol. 84, nr 9

420--424

PL

Efektywną metodą wytwarzania wyrobów pierścieniowych o dużych średnicach w stosunku do wymiarów przekroju poprzecznego jest walcowanie pierścieni na gorąco. Do opracowania procesu oraz zachowania jego stabilnego przebiegu niezbędne jest prawidłowe określenie parametrów geometrycznych walcowanego pierścienia oraz prędkości liniowych i obrotowych walców. Istotnym parametrem procesu jest prędkość przyrostu średnicy wewnętrznej i zewnętrznej walcowanego pierścienia, która determinuje prędkości ruchów walców. W przypadku występowania różnic tych prędkości walcowany wyrób, charakteryzujący się dużą smukłością, ulega zniekształceniu. W artykule przedstawiono wyniki analizy teoretycznej procesu walcowania pierścieni. Opracowano model matematyczny oraz numeryczny MES i poddano je analizie porównawczej. Stwierdzono różnice wymiarów walcowanego pierścienia oraz prędkości jego kształtowania w obu modelach oraz zidentyfikowano przyczyny tych różnic.

EN

An effective method of making ring products with large diameters in relation to the cross – section dimensions is hot ring rolling. In order to develop the process and to maintain its stable flow it is necessary to correct determine the geometric and speed parameters of the rolled object and tools. An essential process parameter is the rate of increase in inner and outer diameter of the rolled ring, which determines speeds of the tool movements. In case of differences in these speeds, the rolling product, characterized by high slenderness, is deformed. The article presents the results of the theoretical analysis of the ring rolling process. A mathematical and numerical model of FEM was developed, which was subjected to comparative analysis. There were differences in the dimensions of the rolled ring and speeds of its shaping in both models and the causes of these differences were identified.