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Influence of EDM process parameters of novel Al7010/B4C/BN hybrid metal matrix nanocomposite

Dirisenapu Gopichand, Salavaravu Laxmanaraju, Dumpala Lingaraju

Composites Theory and Practice

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2023

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R. 23, nr 4

191--196

EN

In this present research work, the electrical discharge machining (EDM) characteristics of an Al7010/2%B4C/2%BN (the reinforcement particles are taken as wt.%) hybrid metal matrix nanocomposite (HMMNC) are discussed. The effect of the EDM process variables like the discharge current (I), pulse on time (Pon), pulse off time (Poff) and gap voltage (Vg) on the response characteristics like the material removal rate (MRR), tool wear rate (TWR), and surface roughness (SR) are presented. The results revealed that the MRR, TWR, and SR grew with an increase in Ip and Pon. MRR, TWR, and SR increased with a rise in Poff up to 25 μs then declined. MRR, TWR, and SR decreased with an increment in gap voltage. The highest MRR was observed for a discharge current of 8 A, Pon of 60 μs, Poff of 25 μs and Vg of 30 V. SR and TWR were the smallest at Ip of 2 A, Pon of 15 μs, Poff of 55 μs and Vg of 60 V. The scanning electron microscope (SEM) micrographs of the machined surfaces revealed voids, craters and micro cracks.

2

Measurement of tool wear using a non-contact method, using a laser measuring system

Grzegorzewski Bartłomiej, Król Patryk

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2021

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No. 116

15--20

EN

Measurement of tool wear using a non-contact method, using a laser measuring system. This article examined the tools - straight cutters with a contactless method using a laser sensor. The first aspect of the research was to determine the influence of the spindle rotational speed on the accuracy of laser measurement. The second aspect of the research was to establish the correlation between the diameter of the tool measured with a laser micrometer and the wear of the tool measured with the microscope. A good (R2> 0.8) Pearson's correlation was found between the measured tool diameter and it’s wear.

PL

Pomiar zużycia narzędzia laserową metodą bezstykową. W ramach pracy zbadano narzędzia – frezy proste metodą bezstykową przy użyciu czujnika laserowego. Pierwszym aspektem badań było ustalenie wpływu prędkości obrotowej wrzeciona na dokładność pomiaru metodą laserową geometrii freza prostego. Drugim aspektem badań było ustalenie korelacji pomiędzy średnicą narzędzia zmierzoną przy użyciu mikrometra laserowego a zużyciem narzędzia określonym przy użyciu mikroskopu. Wykazano dobrą (R2>0,8) korelację pomiędzy zmierzoną średnicą narzędzia a jego zużyciem.

3

Sposoby zwiększania trwałości noży styczno-obrotowych

Bołoz Łukasz

Przegląd Górniczy

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2019

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T. 75, nr 9

28--34

PL

Noże styczno-obrotowe są to narzędzia skrawające stosowane w wielu branżach, zwłaszcza górniczej, drogowej i budowlanej. Kontakt z urabianą calizną powoduje ich ciągłe zużycie. W artykule omówiono rozwiązania konstrukcyjne noży styczno-obrotowych, ich budowę, wymiary oraz stosowane materiały. Opisano zabiegi techniczne stosowane w celu zwiększenie ich trwałości, jak również regeneracji. Omówiono również autorskie, objęte zgłoszeniem o patent na wynalazek, sposoby wydłużenia czasu pracy noży w trudnych warunkach. Pierwsze z tych rozwiązań dotyczy zapewnienia niezakłóconego ruchu obrotowego noża w uchwycie. Zastrzeżenia patentowe obejmują nowatorskie łożyskowanie obrotowe dodatkowej tulei zintegrowanej z uchwytem, która umożliwia ciągły obrót noża. Uchwyt przeznaczony jest do mocowania klasycznych noży handlowych. Wymiana noża odbywa się bez ingerencji w węzeł łożyskowy. Drugie rozwiązanie dotyczy sposobu zabezpieczenia części roboczej noża za pomocą specjalnego elementu z materiału trudnościeralnego. Element ten stanowi ostrze noża o geometrii odbiegającej od standardowo stosowanych słupków z węglików spiekanych. W rozwiązaniu tym ostrze ma kształt odpowiadający formie zużycia noża styczno-obrotowego, przez co jego stalowy korpus nie zużywa się.

EN

Conical picks are cutting tools used in many branches, in particular in the mining, road construction and building branch. Contact with the excavated face causes their constant wear, which is an unfavourable but unavoidable process. In the article various solutions of conical picks, their construction, dimensions and materials used have been discussed. Technical procedures applied to increase the durability of conical picks and their regeneration as well as methods of extending the life of picks working in difficult conditions have been presented. Two author’s methods of extending the life of picks working in difficult conditions, covered by a patent application, have also been presented. The first solution involves ensuring an uninterrupted rotational movement of the pick in the holder. Patent claims include an innovative method of equipping the additional sleeve integrated with the holder with a rotational bearing, which enables a continuous rotation of the commercial pick. The pick replacement does not require interfering with the bearing assembly. The second solution concerns the manner of protecting the working part of the pick by means of a special element made of an abrasion resisting material. This element is the pick tip, the geometry of which varies from the commonly applied posts made of sintered carbide. In this solution, the tip has a shape corresponding to the form of conical pick’s wear, which causes that its steel body does not wear.

4

Directions for increasing conical picks’ durability

Bołoz Łukasz

New Trends in Production Engineering

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2019

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Vol. 2, Iss. 1

277--286

EN

Conical picks are cutting tools used in many branches, in particular in the mining, road construction and building branch. Contact with the excavated face causes their constant wear, which is an unfavorable but unavoidable process. Milling heads of working machines are equipped with several dozen conical picks, and mining in abrasive or hardly accessible rocks can reduce their life to a few hours. It is in the interest of both users and producers to increase their durability, as tools replacement, apart from purchase and logistic costs, results in machine downtimes. In the article various solutions of conical picks, their construction, dimensions and materials used have been discussed. Technical procedures applied to increase the durability of conical picks and their regeneration as well as methods of extending the life of picks working in difficult conditions have been presented. Two author’s methods of extending the life of picks working in difficult conditions, covered by a patent application, have also been presented. The first solution involves ensuring an uninterrupted rotational movement of the pick in the holder. Patent claims include an innovative method of equipping the additional sleeve integrated with the holder with a rotational bearing, which enables a continuous rotation of the pick. The tool equipped with a bearing generates much lower movement resistance than the standard mounting. The holder is designed to mount classic commercial picks. What is important, the pick replacement does not require interfering with the bearing assembly. The second solution concerns the manner of protecting the working part of the pick by means of a special element made of an abrasion resisting material. This element is the pick tip, the geometry of which varies from the commonly applied posts made of sintered carbide. In this solution, the tip has a shape corresponding to the form of conical pick’s wear, which causes that its steel body does not wear. Moreover, there is a possibility of applying a mobile, rotational mounting of the tip to the body.