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1

The effect of selected wedm parameters on cut surface quality of 2017A aluminum

Jamróz Konrad, Gałda Lidia

Technologia i Automatyzacja Montażu

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2024

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nr 1

3--9

EN

With the wire electrical discharge machining (WEDM), good quality machined surfaces can be achieved. The WEDM is worth considering for machining fasteners used in assembly processes. This paper presents a study of the WEDM cutting process of aluminum 2017A using an WEDM machine of the FR 400 type. After applying different cutting speeds, the characteristics of the cut surface were evaluated. Despite some differences in the shape of surface profiles and surface morphology noted after WEDM cutting at different speeds, the analysis of variance concluded that the WEDM cutting speed in the studied variation range of 23-125 μm/s has no significant effect on surface roughness. At the highest speed studied, machining efficiency can be increased, affecting cost and energy reduction, while maintaining an acceptable and comparable level of surface quality after WEDM cutting.

PL

Dzięki obróbce elektroerozyjnej można uzyskać dobrą jakość obrabianych powierzchni. Warto rozważyć zastosowanie obróbki elektroerozyjnej do obróbki elementów złącznych wykorzystywanych w procesach montażowych. W artykule przedstawiono badania procesu cięcia elektroerozyjnego aluminium 2017A z zastosowaniem elektrodrążarki typ FR 400. Po zastosowaniu zróżnicowanej prędkości obróbki poddano ocenie stan powierzchni cięcia. Pomimo zauważonych pewnych różnic w kształcie profili powierzchni i morfologii powierzchni po cięciu elektroerozyjnym z różnymi prędkościami, to w wyniku analizy wariancji stwierdzono, że prędkość cięcia poprzez elektrodrążenie w badanym zakresie zmienności 23-125 μm/s nie wywiera istotnego wpływu na chropowatość powierzchni. Przy największej badanej prędkości można zwiększyć wydajność obróbki, wpływając na zmniejszenie kosztów i energii, zachowując akceptowalny i porównywalny poziom jakości powierzchni po cięciu elektroerozyjnym.

2

Study on the cleanliness of super clean coal prepared by water-only cyclone

Liu Peikun, Wang Hui, Jiang Lanyue, Zhang Yuekan, Yang Xinghua, Li Xiaoyu, Li Feng

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 3

art. no. 168129

EN

Maintaining clean and pristine nature is the key to the use of super clean coal (SCC) for coal-based materials or energy combustion. Herein, SCC is prepared by a new water-only cyclone method, and compared the surface characteristics with the SCC products obtained by conventional chemical deashing method. The results indicate that: FTIR analysis revealed that the chemical method changed the original functional group of coal; BET analysis revealed that the SCC products prepared by the water-only method maintained the micropore volume of the raw coal and yielded a uniform and concentrated distribution of pore sizes, however, the chemical method destroying the original pore structure in the coal; SEM-EDS analysis indicated that the surface of SCC particles that were deashed using the water-only cyclone method was smooth and neat, whereas those obtained using the chemical method were seriously corroded, had a rough surface, and the SCC particles were prone to acid residues and precipitates. This study opens an innovative, simple, and clean method for the preparation of SCC, which further expands and enhances the potential application value of SCC.

3

Experimental study on surface characteristics and improvement of microelectrode machined by low speed wire electrical discharge turning

Sun Y., Gong Y., Liu Y., Li Q., Zhou Y.

Archives of Civil and Mechanical Engineering

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2017

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Vol. 17, no. 4

964--977

EN

Electrical discharge machining (EDM) as the nontraditional machining process has a unique superiority in fabricating microelectrodes due to its non-contact removal mechanism. Therefore, the method of LS-WEDT (low speed wire electrical discharge turning) is firstly proposed to fabricate microelectrodes in this study. More importantly, the multiple cutting strategy is introduced to divide the machining process into rough cut (RC), trim cut (TC) and finishing trim cut (FTC). Experimental results showed that the ridges will appear after RC, the spherical droplets congregation phenomenon can be observed after TC and the surface will be covered with refined grains in nano level after FTC, which disclosed the unique surface characteristics of LS-WEDT. After FTC, the microelectrode of 90 μm in diameter and 1000 μm in length is successfully and firstly fabricated by LS-WEDT method, moreover, it has good surface quality with Ra of 0.59 μm and high dimensional precision with surface profile accuracy of 3.22 μm. Additionally, the comparative analysis was made to investigate the LS-WEDTed and LS-WEDMed surface, the discharge craters distributed in LS-WEDTed surface are longer than LS-WEDM. Finally, the surface quality machined by LS-WEDT after FTC is better than LS-WEDM, which is attributed to the point contact and good flushing conditions.

4

Modelling Tyre-Road Noise with Data Mining Techniques

Freitas E., Tinoco J., Soares F., Costa J., Cortez P., Pereira P.

Archives of Acoustics

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2015

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Vol. 40, No. 4

547--560

EN

The research aimed to establish tyre-road noise models by using a Data Mining approach that allowed to build a predictive model and assess the importance of the tested input variables. The data modelling took into account three learning algorithms and three metrics to define the best predictive model. The variables tested included basic properties of pavement surfaces, macrotexture, megatexture, and unevenness and, for the first time, damping. Also, the importance of those variables was measured by using a sensitivity analysis procedure. Two types of models were set: one with basic variables and another with complex variables, such as megatexture and damping, all as a function of vehicles speed. More detailed models were additionally set by the speed level. As a result, several models with very good tyre-road noise predictive capacity were achieved. The most relevant variables were Speed, Temperature, Aggregate size, Mean Profile Depth, and Damping, which had the highest importance, even though influenced by speed. Megatexture and IRI had the lowest importance. The applicability of the models developed in this work is relevant for trucks tyre-noise prediction, represented by the AVON V4 test tyre, at the early stage of road pavements use. Therefore, the obtained models are highly useful for the design of pavements and for noise prediction by road authorities and contractors.

5

Materiały powłokowe otrzymywane z kationomerów poliuretanowych modyfikowanych funkcjonalizowanym silseskwioksanem. Cz. II. Właściwości użytkowe

Król B., Król P.

Polimery

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2010

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T. 55, nr 11-12

855-862

PL

Powłoki polimerowe otrzymano z wodnych dyspersji kationomerów poliuretanowych modyfikowanych silseskwioksanem funkcjonalizowanym grupami OH (PHIPOSS). Kationomerom przypisano strukturę nanokompozytów kationomerowych i wykazano ich dużą termostabilność, rosnącą wraz ze zwiększaniem zawartości PHIPOSS. Celem badania powłok kationomerowych było wyjaśnienie wpływu PHIPOSS na oddziaływania występujące w fazie zbudowanej ze sztywnych segmentów uretanowo-mocznikowych, decydujące o morfologii wytworzonych powierzchni. Morfologię tę analizowano metodami mikroskopii i DSC. Określono też energię powierzchniową oraz właściwości użytkowe powłok. Przeprowadzono wstępne badania właściwości użytkowych, których wyniki wskazują na możliwość zastosowania opisanych dyspersji wodnych jako ekologicznych lakierów ochronnych na powierzchnie o cechach hydrofilowych.

EN

Studies on the physicochemical properties and applications of polymer coatings obtained from the dispersion of aqueous polyurethane cationomers modified with silsequioxanes functionalized with OH groups [(PHIPOSS) (Table 1)] have been presented. The obtained cationomers has been classified as possessing a nanocomposite structure and high, increasing with PHIPOSS content, thermostability (Fig. 1, Table 3). The coatings were studied with special emphasis on determining the influence of PHIPOSS on the interactions occurring in the rigid polyurethane-urea segments, on which the morphology of the obtained surfaces depend. The morphology was evaluated by microscopic analysis methods (Fig. 3,4, Table 5) and DSC (Fig. 2, Table 4). The surface energy (Table 2,6) and applicability of the coatings were also determined (Table 7). Preliminary studies indicate potential for application of the products obtained in the form of presented aqueous dispersions as environmentally friendly coatings on surfaces of hydrophilic character.

6

Effect of bending on anodized Ti6Al4V alloy: I. Surface layers characteristics

Kierzkowska A., Malinowski M., Krasicka-Cydzik E.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 18, nr 1-2

139--142

EN

Purpose: The plastic deformation behaviour of the anodized binary titanium alloy Ti6Al4V was characterized in mechanical and electrochemical tests. Design/methodology/approach: The effect of tensile and compressive stresses on properties of different clinically relevant surfaces of the deformed by bending implant rods was investigated. The deformation behaviour was characterized by FEM analysis. Relevant surfaces in tensile and compressive zones were characteristics by microhardness and roughness measurements, and electrochemical testing (Ecor, anodic polarization, EIS) in oxygen-saturated Ringer’s solution. Findings: It was concluded that bending influenced mostly the properties of material in the tensile zone of the specimen, whereas the properties of surface layer in the compressive zone and the properties of surface layer in tensile zone after rebending are comparable and not so severe. Research limitations/implications: Studies were performed in static conditions, fatique studies are planned in the future. Practical implications: Results are of great importance in for surgical practice in the in the evaluation of the influence of shaping process applied during pre-operative procedures on the performance of spinal implant systems. Originality/value: In the paper a typical pre-operative procedure of shaping was applied to anodized titanium implants in order to evaluate its influence on the characteristics of the surface layer. Studies were focused on the safety their application in vivo.