Wyniki wyszukiwania - Biblioteka Nauki

1

Badania wymiany ciepła w układzie odlew-forma piaskowa

100%

Mutwil J.

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2003

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tom Vol. 23, Nr 1

93-104

PL

Opisano sposób precyzyjnego instalowania w formach piaskowych termoelementów o małej bezwładności cieplnej. Przedstawiono przykładowe pomiary pól temperatury w układzie odlew-forma.

EN

An installing procedure of the low thermal inertia thermocouples in sand moulds has been described. Exemplary measurements of thermal fields in casting-mould system have been presented.

2

Wpływ temperatury na kinetykę utwardzania mas ze spoiwami chemicznymi

100%

Zych J.

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2001

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tom Vol. 21, Nr 1

161-169

PL

W artykule przedstawiono wyniki badań wpływu temperatury na kinetykę utwardzania mas formierskich wiązanych spoiwami chemicznymi. W badaniach zastosowano opracowaną przez autora metodę ultradźwiękową. Szybkość rozchodzenia się fali w masie ze spoiwem chemicznym jest uzależniona od stopnia zaawansowania reakcji pomiędzy spoiwem a utwardzaczem. W miarę postępowania tej reakcji zwiększa się sprężystość utwardzanej masy, a to powoduje zwiększenie szybkości propagacji fali ultradźwiękowej. Do badań wykonano stanowisko pomiarowe z ultra-dźwiękowym testerem i z komputerem. Pozwala ono w sposób ciągły monitorować przebieg reakcji utwardzania mas. Badania prowadzono dla różnych spoiw i w różnej temperaturze. Po-zwoliło to określić wpływ temperatury na proces wiązania mas.

EN

The paper presents results of the investigations of temperature influence on setting process of molding sands set with chemical binders. The investigations were performed using the ultrasonic method elaborated by the author. An ultrasonic wavespeed in the sand mould with a chemical binder depends on a degree of reaction extent between the binder and hardener. Young's modulus of the moulding sand increases together with the advancement of the reaction, and so does the ultrasonic wavespeed. In the frame of the presented work there was elaborated a measuring-stand using ultrasonic tester supported by a computer - which allows continuous monitoring of the investigated process. The investigations were performed for various binders at various tempera-tures, which allowed to evaluate the influence of temperature on the setting process of the mould-ing sands.

3

Contribution to determination of the life time of chemically self-hardening mould sand

84%

Ignaszak Z.

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2011

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tom Vol. 11, iss. 4

55-60

EN

The article presents the problem of quality of casting moulds made of self-hardening sand, especially for manufacturing moulds for large-sized iron alloy castings. In such cases, unequivocal determination of so-called time of life of moulding sand is one of the most important issues, since it affects usability of a self-hardening sand for making subsequent layers of the mould prepared in time above one hour. Life time, measured in minutes, is dependent on the type of used sand grains, resins and their hardeners (catalysts) and also on the temperature and air humidity. Companies which manufacture and sell binding materials estimate the time of life according to their own criteria, which do not always correspond with real conditions. This article shows the experiences of the author, who has been working as an expert in European foundries for many years. New proposed parameter named FIP characterizing a life time of tested sands is also presented.

4

Changes of gas pressure in sand mould during cast iron pouring

84%

Mocek J. , Samsonowicz J.

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2011

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tom Vol. 11, iss. 4

87-92

EN

The paper presents a test method developed to measure changes of gas pressure in sand moulds during manufacture of iron castings. The pressure and temperature measurements were taken in the sand mould layers directly adjacent to the metal - mould interface. A test stand was described along with the measurement methodology. The sensors used allowed studying the fast-changing nature of the processes which give rise to the gas-originated casting defects. The study examined the influence of binders, clays and refining additives on the nature of the gas evolution process. The effect of the base sand type - quartz or olivine - on the nature of pressure changes was compared. The test stand design ensured the stability of technological parameters in the examined mould elements, and a repeatable process of making pilot castings. The main outcome was classification of sand mixtures in terms of pressure occurring during pouring of iron castings. The obtained results confirm the usefulness of the described method for testing gas pressure occurrence in a sand mould.

5

Microstructural features of the grain-refined sand cast AlZn20 alloy

67%

Haberl K. , Krajewski W. K. , Schumacher P.

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2010

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tom Vol. 55, iss. 3

837-841

EN

The influence of various titan-containing grain refiners on an AlZn20-alloy was examined using thermal analysis, light microscopy and scanning electron microscopy, and evaluation of grain size. The aim of this study was to determine microstructural features. The study showed that the magnitude of the melts undercooling, initial temperatures of primary nucleation and grain refinement are highly influenced by the grain refiner used.

PL

W pracy badano wpływ różnych zapraw modyfikujacych, zawierających tytan, na strukturę stopu AlZn20. W badaniach stosowano techniki analizy termicznej, mikroskopii świetlnej i elektronowej oraz analizę wielkości ziarna. Badania wykazały, że wielkość przechłodzenia i cechy struktury stopu zmodyfikowanego silnie zależą od rodzaju użytego modyfikatora.