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Synthesis of nano-structured duplex and ferritic stainless steel powders by dry milling and its comparison with wet milling

Shashanka R., Uzun Orhan, Chaira D.

Archives of Metallurgy and Materials

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2020

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Vol. 65, iss. 1

5--14

EN

In the present paper, elemental Fe, Cr and Ni powders were used to fabricate nano-structured duplex and ferritic stainless steel powders by using high energy planetary ball milling. We have studied the effect of milling atmosphere like wet (toluene) and dry (argon) milling of elemental Fe-18Cr-13Ni (duplex) and Fe-17Cr-1Ni (ferritic) powders for 10 h in a dual drive planetary mill. Stearic acid of 1wt.% was added during milling to avoid agglomeration. The dry and wet milled duplex and ferritic stainless steel powders were characterized by XRD, SEM and particle size analysis techniques. We have found that both the milling atmospheres have great influence in controlling the final particle morphology, size and phase evolution during milling. It was reported that dry milling is more effective in reducing particle size than the wet milling. The Nelson-Riley method of extrapolation was used to calculate the precise lattice parameter and Williamson-Hall method was used to calculate the crystallite size and lattice strain of both the stainless steel milled in argon atmosphere. Dry milled duplex and ferritic stainless steel were then consolidated by conventional sintering method at 1100, 1200 and 1300°C temperatures under argon atmosphere for 1 hour.

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Optimization of Process Parameters During End Milling and Prediction of Work Piece Temperature Rise

Bhirud N. L., Gawande R. R.

Archive of Mechanical Engineering

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2017

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Vol. LXIV, nr 3

327--346

EN

During the machining processes, heat gets generated as a result of plastic deformation of metal and friction along the tool–chip and tool–work piece interface. In materials having high thermal conductivity, like aluminium alloys, large amount of this heat is absorbed by the work piece. This results in the rise in the temperature of the work piece, which may lead to dimensional inaccuracies, surface damage and deformation. So, it is needed to control rise in the temperature of the work piece. This paper focuses on the measurement, analysis and prediction of work piece temperature rise during the dry end milling operation of Al 6063. The control factors used for experimentation were number of flutes, spindle speed, depth of cut and feed rate. The Taguchi method was employed for the planning of experimentation and L18 orthogonal array was selected. The temperature rise of the work piece was measured with the help of K-type thermocouple embedded in the work piece. Signal to noise (S/N) ratio analysis was carried out using the lower-the-better quality characteristics. Depth of cut was identified as the most significant factor affecting the work piece temperature rise, followed by spindle speed. Analysis of variance (ANOVA) was employed to find out the significant parameters affecting the work piece temperature rise. ANOVA results were found to be in line with the S/N ratio analysis. Regression analysis was used for developing empirical equation of temperature rise. The temperature rise of the work piece was calculated using the regression equation and was found to be in good agreement with the measured values. Finally, confirmation tests were carried out to verify the results obtained. From the confirmation test it was found that the Taguchi method is an effective method to determine optimised parameters for minimization of work piece temperature.

3

Wpływ warunków chłodzenia na chropowatość powierzchni po frezowaniu

Leppert T., Paczkowski T., Polasik R.

Mechanik

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2016

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R. 89, nr 10

1420--1421

PL

W artykule przedstawiono badania porównawcze chropowatości powierzchni po frezowaniu – na sucho, z MQL i emulsją – stali węglowej C45 i stopu aluminium PA4, w zakresie wysokich prędkości skrawania.

EN

The article presents a comparative study of surface roughness after dry milling, with the MQL and emulsion of C45 carbon steel and aluminum alloy PA4 at high cutting speeds.

4

Badania sił skrawania podczas frezowania na sucho, z MQL i emulsją

Leppert T, Polasik R.

Mechanik

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2012

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R. 85, nr 8-9CD (SOS)

431--438

5

Badania chropowatości powierzchni po frezowaniu na sucho, z MQL i emulsją

Leppert T

Mechanik

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2012

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R. 85, nr 8-9CD (SOS)

423--430

6

Energooszczędna technologia przygotowania granulatów ceramicznych. Cz. I – Przemiał i granulacja

Serkowski S., Guenter H.

Materiały Ceramiczne

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2011

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T. 63, nr 2

266-272

PL

Aktualnym standardem technologicznym wytwarzania granulatów ceramicznych w produkcji płytek ceramicznych jest przemiał na mokro i wytwarzanie granulatu w suszarniach rozpyłowych. Są to rozwiązania wysoce energochłonne, a zwłaszcza proces wytwarzania granulatu z gęstwy ceramicznej. W artykule przedstawiono nową koncepcje technologiczną charakteryzującą się wydatnie zmniejszoną energochłonnością. Zastosowanie nowoczesnego, ciągłego przemiału surowców wilgotnych z separacją ziaren prowadzi do znaczącego obniżenia zużycia energii. Wysoki stopień automatyzacji sterowania procesem przemiału umożliwia łatwe sterowanie stopniem przemiału i pobór energii w zależności od wielkości i wilgotności nadawy. Suche mlewo uzyskane w proponowanej instalacji jest granulowane w mieszalniku intensywnym przy minimalnym dodatku wody. W procesie standaryzacji uzyskuje się granulat o uziarnieniu takim samym jak w suszarniach rozpyłowych. Granulat uzyskany tą metoda posiada o ok. 10 % wyższą gęstość ponieważ nie zawiera pustych granul, a materiał granulowany jest lepiej zagęszczony. Proponowana technologia cechuje się małymi gabarytami urządzeń, wysokim stopniem automatyzacji i umożliwia zredukowanie poboru energii ok. 8 razy w przypadku stosowania suchych surowców i ok. 4-5 razy w przypadku stosowania surowców o średniej wilgotności 8-9 %. Zaprezentowano wyniki badań laboratoryjnych i prób przemysłowych oraz analizę efektów ekonomicznych wynikających z obniżenia zużycia wody i energii, a także wykazano możliwość eliminacji stosowanych w tradycyjnej technologii dodatków upłynniających i spoiw.

EN

Wet milling and production of granulates in spray dryers is the current technological standard of the production of ceramic granulates in the manufacturing of ceramic tiles. These solutions, and particularly the process of producing the granulate from a ceramic slurry, are highly energy-consuming. The article presents a new technological concept characterized by significantly lower consumption of energy. The use of the modern continuous milling of wet materials with grain separation leads to significant reduction of energy consumption. High automation of the milling process control allows for easy control of the milling degree depending on the feed size and moisture. Dry material obtained in the presented installation is granulated in an intensive mixer with the minimum addition of water. During the standardization process, the granulate obtained is of the same graining as the granulate obtained in spray dryers. Density of granulate obtained by means of this method is about 10 % higher as it does not contain hollow granules and the granulated material is more concentrated. The article depicts the results of laboratory analyses and industrial tests; it also analyses the economic effects arising from the reduction of water and energy consumption. Moreover, the article focuses on the possibility to eliminate fluidifying additives and binding agents used in the traditional technology. The suggested technology is characterized with small device dimensions, high level of automation, and it makes it possible to reduce energy consumption by approximately 8 and 4-5 times in case of using the dry and medium moisture materials, respectively.