Experiment and Numerical Modelling the Time of Plate-Shape Casting Solidification vs. Thermal Conductivity of Mould Material/ Eksperyment I Modelowanie Numeryczne Czasu Krzepniecia Odlewu Płyty W Funkcji Przewodnictwa Cieplnego Materiału Formy

The paper presents results of measuring thermal conductivity of green sand mould material and time of castings solidification evaluated from cooling curves. During the experiments pure Cu (99,8 %) plate was cast into the examined sand moulds. Basing on the measurements it was stated that thermal conductivity of the moulding sand has complex temperature variability, especially during the water vaporization. It was confirmed that water vaporization strongly influences thermal conductivity of the moulding sand in the first period of the mould heating by the poured casting. The obtained dependence should be used in the numerical calculations to improve their accuracy.Keywords: castings, sand mould, thermal conductivity, solidification, numerical modelling Artykuł prezentuje wyniki pomiarów współczynnika przewodzenia ciepła materiału wilgotnej formy piaskowej z bentonitem oraz czas krzepnięcia odlewu płyty z miedzi o czystości 99.8%. Na podstawie eksperymentów stwierdzono, że temperaturowa zależność przewodności cieplnej badanej masy formierskiej nie ma prostego przebiegu, szczególnie w okresie odparowywania wilgoci, a uzyskana w części eksperymentalnej temperaturowa zależność powinna być stosowana w obliczeniach numerycznych w celu polepszenia jakości obliczeń.

Archives of Metallurgy and Materials

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

“…The a M heat diffusivity coefficient can be determined from the registered temperature field of the mould described by error function [4,25]: …”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Range Of Thermal Conductivity Changes Of Wet Green Foundry Sand During Casting Solidification

Krajewski¹,

Piwowarski²

2015

Self Cite

The effect of different binder levels on the heat absorption capacity of moulding mixtures made by the phenolic urethane cold-box process

Diószegi

et al. 2017

J Therm Anal Calorim

The phenolic urethane cold-box (PUCB) process was first introduced to the foundry industry in the late 1960s. Since then, it has become one of the most popular methods to make foundry purpose sand moulds and cores, utilized in the manufacturing of aluminium and cast iron cast components. The factors to be considered, affecting the general performance of a PUCB moulding mixture, are the temperature of sand, the moisture content, the mixing conditions, etc. Moreover, there are variable production parameters such as binder level, to improve certain properties of the mould and/or the core based on their specific area of application. These are mainly mechanical properties such as tensile or splitting strength. They have significant influences on the behaviour of the moulding material and are usually tested at room temperature. Although the production phases of the PUCB system are refined to a high extent today, the effect of binder content on the quality of the mould/core and the final casting should be supported by new approaches also in thermal sciences, interpreted in high-temperature environment. In this work, different PUCB mixtures were produced to evaluate the effect of various binder levels on the thermophysical properties of sand cores. Thermogravimetry, differential thermal analysis and a novel application of Fourier thermal analysis were used to study the decomposition processes of the PUCB mixture and to reveal the impact of binder level on the heat absorption (cooling) capacity of sand cores at temperatures relevant in the manufacturing of cast iron parts (1300 ± 10°C).

Thermophysical aspects of reclaimed moulding sand addition to the epoxy-SO2 coremaking system studied by Fourier thermal analysis

Diószegi

et al. 2017

J Therm Anal Calorim

The most important advantage of foundry purpose moulding sand is that it can be reclaimed and reused through the casting manufacturing process. Supplying the foundry with a new source of material, sand reclamation brings along both environmental and economic advantages. Utilization of used sand can be considered as a common technological routine in the production of most types of chemically bound moulding materials. The epoxy-SO 2 process is prevalent in the processing of cast iron engine components worldwide. Based on its excellent properties, it is mainly suitable for producing internal sand cores with complex geometry. Even though reclaimed sand addition is an active and well-functioning feature in ferrous foundries, the scientific and thermophysical background of its effects on the casting process is yet to be explored. In this work, the thermal aspects of different reclaimed sand levels in the epoxy-SO 2 moulding system were examined. Thermogravimetry and differential thermal analysis of the epoxy-SO 2 and reclaimed sand in focus were carried out to obtain basic understandings about their high-temperature behaviour. A state-of-the-art Fourier thermal analysis method presented in a recent paper was used at temperatures corresponding to actual cast iron production (1300 ± 10°C), contrary to the previous tests at the typical temperature range of aluminium melt processing (660 ± 10°C). By the right of the method, the effects of reclaimed sand addition on the heat absorption (cooling) capacity of the epoxy-SO 2 moulding mixtures were investigated.