Wyniki wyszukiwania - BazTech

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Optimization of Ladle Tilting Speed for Preventing Temperature Drops in the Die Casting Process

Ando Haru, Minamide Daichi, Takagi Yuto, Yano Ken’ichi, Nakamura Naoto, Sano Masahiro, Aoki Takahiro, Nemoto Yasunori

Journal of Casting & Materials Engineering

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2022

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Vol. 6, no. 4

69--75

EN

In die casting, molten metal poured into a shot sleeve is pressed into a mold by a plunger at high speed. The temperature of the metal drops significantly while it is being poured from the ladle to the shot sleeve, resulting in casting defects such as misrun flow lines. Although it is important to control the temperature at all stages of the process, a method for minimizing temperature loss has not yet been clarified to date. In this study, the cause of the temperature drop in the shot sleeve was clarified, and a method of optimizing the ladle tilting speed was proposed to prevent temperature drop. First, experiments were conducted to measure the decrease in metal temperature in the sleeve during pouring. These experiments revealed that the metal cools significantly from the moment it touches the shot sleeve. Therefore, the time from the first contact between the shot sleeve and the metal to the start of pouring was set as the objective function. A genetic algorithm was then used to derive the optimal ladle tilting speed pattern to suppress the temperature drop. This analysis confirmed that the metal was poured without flowing out or running ahead and that the immediate liquid level vibration after pouring was suppressed, thus ensuring stable pouring.

2

Wpływ nagłego obniżenia temperatury zewnętrznej podczas procesu wiązania na trwałość tynków gipsowych

Francke B., Popczyk J.

Materiały Budowlane

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2017

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nr 10

130--131

3

Ocena skuteczności napraw realizowanych w warunkach nieoczekiwanego obniżenia temperatury

Wojnowski D.

Materiały Budowlane

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2017

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nr 11

76--78

PL

Celem artykułu jest przedstawienie wstępnych wyników badań pozwalających na ocenę skuteczności napraw konstrukcji betonowych realizowanych w warunkach nieoczekiwanego obniżenia temperatury. Przeprowadzono badania wytrzymałości na ściskanie, stosując dwie zaprawy PCC do napraw konstrukcji betonowych i wyznaczono przyrost wytrzymałości w czasie. Jedna zaprawa była przeznaczona do stosowania w temperaturze od 1°C, a druga w temperaturze od 5°C. Próbki dojrzewały w zaprojektowanych, zmiennych cyklach temperaturowych symulujących nieoczekiwane obniżenie temperatury. Otrzymane wyniki badań oraz przeprowadzona analiza pokazują negatywny wpływ obniżonej temperatury na wytrzymałość na ściskanie i wskazują na potrzebę bardziej szczegółowego rozpoznania problemu.

EN

The aim of this article is to present preliminary results of the study allowing to evaluate the effectiveness of repair of concrete structures realized in conditions of unexpected reduction of temperature. Compressive strength tests were performed on two PCC mortars for repair of concrete structures and it was determined increase of compressive strength over time. One mortar was intended for use at temperatures from 1°C, and the second at a temperature of 5°C. Samples cured in designed, variables of temperature cycles simulating an unforeseen reduction of temperature. The obtained results and the analysis show the negative effect of the reduced temperature on the compressive strength. The results of the research, which allows for an initial analysis of the issue, indicate the appropriateness of the topic and the need for a deeper recognize the problem.

4

New materials and ideas to be used in adiabatic engines

Jaskólski J., Krzyżak R.

Journal of KONES

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2004

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Vol. 11, No. 1-2

288-294

EN

This note concerns several topics. Firstly, a review of some less-known topics regarding the contemporary knowledge on TBC and piston caps is given. Then, it turns out that almost unknown New Periodic System of Elements can be of assistance to predict several properties of new TBC materials. Theoretically, there exist a possibility to join Si-AL-piston alloy with yttria-stabilised zirconia (and the like) by means of feId spars (plagioclase). The latter do not attain to melting temperature and can be arrested within the alloy. A shortened integral optical equation in the manner of inverse problem was used to compute the temperature drop accros the piston cap's layers. The YSZ layer operating in this hypothetical engine gave 517.5 graduate K drop, whereas the feldspar gave about 100-50graduate K temperature drop per mm. This arrangement would give minimised radiation and more or less 'cold' engine(piston). Perhaps, oxides of the thalium-sesquioxide-type structure would be better to stick to metal than the commonly used ones.

5

The thermal load of heavy loaded brake mechanisms

Dzhanakhmedov A. K., Aliyev I. I., Janahmadov E. A.

International Journal of Applied Mechanics and Engineering

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2002

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Vol. 7, Spec. is

319-322

EN

In the present operation the made attempt to estimate thermomechanical baing of a brake assembly of a drill winch in multiplis process of landing of tubes. The calculations have shown, that the considerable influencing on the basic indexs of quality of surface layer and mechanical performances of a material renders cycliness (heating and chilling) and velocity of calorific process.