Energieeffizienz beim Spanen/Energy efficiency at machining - Investigations about the influence of minimun quantity lubrication (MQL) at final cutting

2017 ◽  
Vol 107 (05) ◽  
pp. 352-358
Author(s):  
S. Prof. Simon ◽  
S. Wichmann ◽  
A. Brill

Von der Brandenburgischen Technischen Universität (BTU) sind in Zusammenarbeit mit der TU Liberec Untersuchungen zur Verbesserung der Energieeffizienz an spanenden Werkzeugmaschinen durchgeführt worden. Im Gegensatz zu bereits durchgeführten Untersuchungen wurde der Fokus hier auf das Belastungsverhalten im Teillastbereich gerichtet. Die durchgeführten Untersuchungen beschränkten sich auf das Längsdrehen mit geringen Schnitttiefen. Als Werkstoffe kamen ein Baustahl und ein Vergütungsstahl zum Einsatz. Durch die Bestimmung der Leerlaufleistung der verwendeten Drehmaschine waren tatsächliche Aussagen über die Schnittleistung möglich. Für das Ermitteln des Wirkungsgrades wurden auch die Schnittleistungen bei verschiedenen Drehzahlen aufgenommen. Alle weiteren Spanungsbedingungen blieben für die Untersuchungen konstant. Im Ergebnis der Untersuchung bestätigte sich das Potenzial der Minimalmengenschmierung. Der Wirkungsgrad verbesserte sich durchschnittlich um 5 %. Beachtenswert ist der Einfluss des Einstellwinkels. Hier liegt das Optimierungspotenzial der Energieeffizienz in Summe bei 14 %. Die Untersuchungen ergaben weiterhin eine hohe Korrelation von Spanungsbedingungen, Werkstückwerkstoff und verwendetem Schmiermittel.   The Brandenburg University of Technology has carried out investigations in cooperation with the technical University of Liberec to improve the energy efficiency of cutting machine tools. In contrast to investigations already carried out, the focus here was on the loading behavior in the partial load range. The investigations carried out were limited to longitudinal turning with low cutting depths. A structural steel and a tempering steel were used as materials. By determining the no-load power of the used lathe, actual statements about the cutting performance were possible. For the determination of the efficiency, the cutting performance was recorded at different speeds. All further stress conditions remained constant for the investigations. As a result of the investigation, the potential of minimum quantity lubrication was confirmed. The efficiency improved by an average of 5 %. The influence of the angle of setting was remarkable. The optimization potential of energy efficiency was at 14 %. The investigations also revealed a high correlation between stress conditions, workpiece material and lubricant used.

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Shahin Haghnazari ◽  
Vahid Abedini

AbstractThis paper presents an effort to model the process parameters involved in turning of alloy steel AISI 4340 workpiece material with Al2O3 and CuO hybrid nanofluids using the minimum quantity lubrication (MQL) method. In this paper, the effect of mixing two nanoparticles (Al2O3 and CuO) with different weight percent in environmentally friendly water-based cutting fluid, the rotational speed, and the feed rate has been investigated on the surface roughness and the machining forces using the response surface method. The results of the experiments show that the hybrid nanofluid containing 0.75 CuO with 0.25 Al2O3 has the best output for the machining forces and the surface roughness. Also, in the best composition of the nanoparticles (0.75 CuO with 0.25 Al2O3), the lowest value of machining forces has been achieved at a feed rate of 0.08 mm per revolution and the rotational speed 1000 rpm as well as the lowest value of the surface roughness at a feed rate of 0.08 mm per revolution and the rotational speed 710 rpm.


Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2125 ◽  
Author(s):  
Janusz Tomczak ◽  
Zbigniew Pater ◽  
Tomasz Bulzak

This paper presents selected numerical and experimental results of a skew rolling process for producing balls using helical tools. The study investigates the effect of the billet’s initial temperature on the quality of produced balls and the rolling process itself. In addition, the effect of billet diameter on the quality of produced balls is investigated. Experimental tests were performed using a helical rolling mill available at the Lublin University of Technology. The experiments consisted of rolling 40 mm diameter balls with the use of two helical tools. To determine optimal rolling parameters ensuring the highest quality of produced balls, numerical modelling was performed using the finite element method in the Forge software. The numerical analysis involved the determination of metal flow kinematics, temperature and damage criterion distributions, as well as the measurement of variations in the force parameters. The results demonstrate that the highest quality balls are produced from billet preheated to approximately 1000 °C.


Author(s):  
Hanna I. Severina ◽  
Svitlana M. Gubar ◽  
Ivan V. Bezruk ◽  
Anna S. Materiienko ◽  
Liudas Ivanauskas ◽  
...  

1-(4-methoxyphenyl)-5-[2-[4-(4-methoxyphenyl)piperazin-1-yl]-2-oxo-ethyl]pyrazolo[3,4-d]pyrimidin-4-one has been reported as a promising new anticonvulsant drug candidate with a code name “Epimidin”. A new HPLC method for the related substances determination of potential active pharmaceutical ingredient has been developed and validated. The method uses ACE C18 column (250x4.6mm, 5µm) and gradient elution. Mobile phase consisted of a mixture of methanol R (mobile phase A) and phosphate buffer solution with triethanolamine, adjusted to pH 7.0 (mobile phase B). During the analysis, the ratio of mobile phases was changing according to a gradient mode at a flow rate of 1ml/min. The DAD detection was set at 240nm. The method was validated according to the ICH guidelines and requirements of State Pharmacopoeia of Ukraine. Drug substance was thoroughly explored for stability assessments under various stress conditions such as high temperature, as well as the influence of strong acid and base and oxidizing agents. The obtained solutions were analyzed by HPLC and LC/MS. It has been shown that the substance Epimidin was not resistant to the action of peroxide, alkali and acid decomposition – the mentioned stress conditions lead to the formation of unidentified impurities.


2015 ◽  
Vol 19 (6) ◽  
pp. 2233-2244
Author(s):  
Slobodan Misanovic ◽  
Zlatomir Zivanovic ◽  
Slaven Tica

Research in this paper comprised experimental determination of energy efficiency of different bus subsystems (diesel bus, trolleybus and fully electric bus) on chosen public transport route in Belgrade. Experimental measuring of energy efficiency of each bus type has been done based on the analysis of parameters of vehicle driving cycles between stops. Results of this analysis were basis for development of theoretical simulation model of energy efficiency. The model was latter compared with the results of simulation done by "Solaris bus & Coach" company for the chosen electric bus route. Based on demonstrated simulation, characteristics of electric bus batteries were defined, the method and dynamic of their recharge was suggested, as well as choice for other aggregates for drive system and technical characteristics for the electric buses were suggested.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Lukasz Madej ◽  
Adam Legwand ◽  
Mohan Setty ◽  
Mateusz Mojzeszko ◽  
Konrad Perzyński ◽  
...  

AbstractHerein, we evaluate the nanoindentation test capabilities in the determination of flow stress characteristics of the matrix material in porous sinters. The Distaloy AB sample with 15% porosity after the sintering operation is selected as a case study for the investigation. 2D and 3D imaging techniques are employed first to highlight difficulties in identifying reliable nano hardness measurement zones for further properties evaluation. Then, nanoindentation test results are acquired with Berkovich tip pressed under various loads at different locations in the sample. Systematic indentations in the quartz sample are used as a cleaning procedure to minimize the effect of the possible build-up around the indenter tip. The representative indentation load range is selected based on the extracted material characteristics. With that, the stress–strain response of the sinter matrix material is identified. The reliability of the determined flow stress curve is confirmed with the use of conical nanoindentation measurement results and finite element simulations. Obtained results show that it is possible to calculate reliable flow stress characteristics of the matrix in the porous samples, with the assumption that experiments under various loading conditions and from various locations in the matrix are performed. It is also pointed out that various indentation loads should be used to eliminate the influence of the pile-up or scale effects that affect the overall material response.


INDIAN DRUGS ◽  
2021 ◽  
Vol 58 (11) ◽  
pp. 53-59
Author(s):  
Tukaram M. Kalyankar ◽  
◽  
Shital S. Dange ◽  
Shivraj B. Hambarde ◽  
Shailesh J. Wadher ◽  
...  

A simple, accurate and precise UV spectrometric method has been developed for the simultaneous determination of valsartan and hydrochlorothiazide in tablet dosage form. Spectra of valsartan and hydrochlorothiazide in methanol and water (50:50 V/V) show λ max at 250.0 nm and 271.4 nm, respectively. Valsartan and hydrochlorothiazide are subjected to various stress conditions like acid, alkali, thermal and photolytic degradation. Beer’s law was obeyed in concentration range of 4- 24 µg mL-1 for valsartan and 0.5-3 µg mL-1 for hydrochlorothiazide at their respective wavelengths. The proposed method was successfully applied to tablet dosage form for determination of both drugs. The percentage recovery of valsartan and hydrochlorothiazide were found to be 100.19 % and 99.51 %, respectively. A novel accurate and precise stability indicating spectroscopic method has been developed for estimation of valsartan and hydrochlorothiazide.


Author(s):  
Stephen A. Batzer ◽  
Alexander M. Gouskov ◽  
Sergey A. Voronov

Abstract The dynamic behavior of deep-hole vibratory drilling is analyzed. The mathematical model presented allows the determination of axial tool and workpiece displacements and cutting forces for significant dynamic system behavior such as the entrance of the cutting tool into workpiece material and exit. Model parameters include the actual rigidity of the tool and workpiece, time-varying chip thickness, time lag for chip formation due to tool rotation and possible disengagement of drill cutting edges from the workpiece due to tool and/or workpiece axial vibrations. The main features of this model are its nonlinearity and inclusion of time lag differential equations which require numeric solutions. The specific cutting conditions (feed, tool rotational velocity, amplitude and frequency of forced vibrations) necessary to obtain discontinuous chips and reliable removal are determined. The stability conditions of excited vibrations are also investigated. Calculated bifurcation diagrams make it possible to derive the domain of system parameters along with the determination of optimal cutting conditions.


Author(s):  
Pushparghya Deb Kuila ◽  
Shreyes Melkote

Laser-assisted micromilling is a promising micromachining process for difficult-to-cut materials. Laser-assisted micromilling uses a laser to thermally soften the workpiece in front of the cutting tool, thereby lowering the cutting forces, improving the dimensional accuracy, and reducing the tool wear. Thermal softening, however, causes the workpiece material to adhere to the tool and form a built-up edge. To mitigate this problem and to enhance micromachinability of the workpiece in laser-assisted micromilling, this article investigates the following lubrication and cooling methods: (1) minimum quantity lubrication and (2) vortex tube cooling. Experiments utilizing the two methods are carried out on a difficult-to-cut stainless steel (A286), and the surface morphology, tool condition, burr formation, groove dimensional accuracy, surface finish, and cutting forces are analyzed. Results show that the combination of laser-assisted micromilling and minimum quantity lubrication yields the least amount of tool wear, lower resultant force, better groove dimensional accuracy, and no built-up edge. While vortex tube cooling with laser-assisted micromilling produces smaller burrs compared to minimum quantity lubrication, it yields larger changes in groove dimensions and is characterized by built-up edge formation. Possible physical explanations for the experimental observations are given.


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