Wyniki wyszukiwania - BazTech

1

Key determinants for high-alloyed cast irons for mechanical engineering

Pacha-Gołębiowska H., Piekarska W.

International Journal of Applied Mechanics and Engineering

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2022

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Vol. 27, no. 1

146--167

EN

This work presents the factors determining cast iron, and particularly austenitic high-alloy cast iron as a construction material, which is ranked among the leading casting alloys of iron with carbon, mainly due to its very good service properties, which makes it dedicated as a material for automotive castings, pipe and fitting castings and components resistant to elevated temperatures, corrosion and abrasive wear. Construction materials currently used in industry have increasingly better properties and their potential is depleting quickly. This forces the manufacturers to adjust the requirements and production capabilities of cast iron using the most modern technologies that give the expected beneficial economic and operating effects. The paper quotes the results of research in the field of the offered technologies that give special surface features to machine parts made of cast iron by modernising the parameters of the technological process of obtaining high-alloy austenitic cast iron, i.e., by applying coatings, as well as by appropriate surface treatment, the aim of which is and reinforce the material surface with those properties which are important in a given application.

2

Study on Tool Condition Parameters Intended for Smart Tool Management in Filleted End Milling

Sekine Tsutomu

Advances in Science and Technology. Research Journal

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2021

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Vol. 15, no 3

108--116

EN

Filleted end milling is commonly used as a versatile manufacturing process, whereas the optimization for tool condition management is one of the continuously noticed topics. It can also contribute to the achievement of Sustainable Development Goals. A lot of outcomes have been reported so far in the experimental investigations of tool condition parameters. However, the findings and knowledge from theoretical perspective are relatively scarce to advance smart tool management. Hence, the aim of this study is to give theoretical consideration with tool condition parameters. The investigations focus on filleted end milling with some variations of machining conditions. Several tool condition parameters were theoretically proposed after illustrating geometrical modeling with variable description. Then, the demonstrations and discussion were made based on the computational results in filleted end milling. The results visually and numerically ascertained novel findings regarding several characteristics of tool condition parameters

3

Comparative Study on Path Interval and Two Tool Condition Parameters in Ball and Filleted End Milling

Sekine Tsutomu

Advances in Science and Technology. Research Journal

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2021

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Vol. 15, no 4

311--320

EN

Milling is widely used as a versatile, highly automated manufacturing process. The selection of tool and its machining conditions is an ever-present challenge inherent in the process. To provide some findings contributable for the process planning, this study focuses on ball and filleted end milling. After the path interval determinations were explained briefly, the characteristics of each procedure were revealed with experimental verifications. The results of computational procedures showed good agreement with the experimental ones. Then, predominant frictional distance and cutting speed were proposed for effective selection of machining conditions. The discussion was given based on the results obtained from the demonstrations. Moreover, the relationships to path interval were elucidated through the discussion. In conclusion, several outcomes were organized from the experimental and numerical evidences.

4

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.

5

Badanie relacji między wybranymi warunkami obróbki frezowaniem a siłami skrawania

Bromberek F., Matuszewski M., Oborski I. L., Polasik R., Styp-Rekowski M., Wegrzyniak T.

Obróbka Metalu

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2017

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nr 2

10--13

EN

In the paper results of research of the cutting forces in the milling process were presented. Relations between the number of edges, the length of the tool and the value of the cutting force components: F , F and F , were determined. Investigations were conducted for three xy z materials: Al alloy 3.1255, steel 1.0037 and cast iron 0.6025. One stated that both variables were affecting the value of the cutting forces, however observed changes are greater for the variable number of cutting edges.

PL

W artykule przedstawiono rezultaty badań sił skrawania w procesie frezowania. Określono relacje między liczbą ostrzy oraz długością narzędzia a wartością składowych sił skrawania: Fx, Fy i Fz. Badania przeprowadzono dla trzech materiałów: stopu Al 3.1255, stali 1.0037 i żeliwa 0.6025. Stwierdzono, że obydwie zmienne mają wpływ na wartość sił skrawania, przy czym zaobserwowane zmiany są większe dla zmiennej liczby ostrzy.

6

The effect of machining conditions on the forces in the process of roller brush machining

Matuszak J.

Advances in Science and Technology. Research Journal

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2017

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Vol. 11, no 4

294--300

EN

Because of its advantages, brushing processing has many uses. The main ones include the removal of corrosion products, surface cleaning, deburring and shaping the properties of the surface layer. The intensity of these processes depends on the degree of impact of brush fibres on the work surface. In the case of tools, in which the resilient fibres are the working elements, forces in the brushing process, apart from the machining parameters, depend on the characteristics and overall dimensions of individual fibres. The paper presents the results of studies of the influence of technological parameters and type of fibres on the radial force in the brushing process.

7

Właściwości tribologiczne warstwy wierzchniej elementów z żeliwa EN-GJS2131 po obróbce wykończeniowej toczeniem

Feldshtein E., Pacha-Gołębiowska H.

Tribologia

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2013

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nr 2

57--67

PL

W pracy przedstawiono wyniki badań właściwości tribologicznych powierzchni elementów wykonanych z żeliwa GJS2131 po obróbce wykończeniowej toczeniem z zastosowaniem różnych materiałów narzędziowych i w zróżnicowanych warunkach obróbki. Wykonane badania wykazały mniejszą wartość współczynnika tarcia w przypadku użycia materiału supertwardego CBN7050 oraz wolniejszy wzrost temperatury w strefie tarcia dla tego materiału narzędziowego o blisko 20% w stosunku do płytek z węglika spiekanego K10. Właściwy dobór warunków toczenia i materiałów narzędziowych w znaczący sposób wpływa na intensywność zużywania WW elementów trących. Najniższą wartość intensywności zużycia objętościowego dla żeliwa GJS2131 uzyskano przy zastosowaniu materiału CBN7050 w warunkach toczeniu z dużymi prędkościami i niewielkimi posuwami.

EN

In this paper, the results of studies on the surface tribological properties of parts made of spheroidal graphite cast iron GJS2131 with a ferrite-pearlite structure after finish turning with different tool materials and machining conditions are presented. Investigations revealed minimum values of the friction coefficient and the slower, 20%, increase of temperature in the case of inserts made of “superhard” material CBN7050 compared to the hard alloy K10. The correct choice of turning conditions and tool material significantly affects the intensity of the wear of the rubbing surfaces. The lowest values of the volumetric wear rate intensity are registered in the case of CBN7050 tool material when turning at high speeds and low feed rates and in the case of K10 material when turning at low speeds and high feed rates. When using the investigated tool materials, very significant correlation between the state of the surface layer and its tribological characteristics has been set. In particular, the material CBN7050 has high coefficients of correlation between the intensity of wear Iv and the degree of distances distortion ∆d/d between the planes of the crystal net, macrostresses (σ1 + σ2), microhardness HV0.05, and the friction coefficient, as well as between the values of (σ1 + σ2) and the friction coefficient or between the dislocation density, microhardness and the friction coefficient. The coefficients of correlation between the friction coefficient and wear rate are less significant. This is evidence of a moderate influence of the friction coefficient on the wear rate of turned surfaces.

8

Kształtowanie warstwy wierzchniej elementów żeliwnych w procesie frezowania igłowego

Feldshtein E., Barshaj I.

Obróbka Metalu

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2012

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nr 2

6-11

PL

Jedną z metod obróbki powierzchni płaskich jest frezowanie igłowe. Proces ten znacznie różni się od tradycyjnych metod obróbki, ponieważ narzędzie ma przerywany profil skrawający, a proces skrawania cechuje się sprężysto-plastycznym oddziaływaniem znacznej ilości ostrzy skrawających na powierzchnię obrabianą. Proces frezowania igłowego zapewnia osiągnięcie właściwej chropowatości powierzchni oraz umocnienie warstwy wierzchniej wskutek sprężysto-plastycznego oddziaływania igieł, m.in. stopień umocnienia sięga do 40 procent. Zapewnia to lepszą przyczepność smaru, wzrost odporności na zużycie i innyh właściwości tribologicznych powierzchni.