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

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.

Section: Results Of Fourier Thermal Analysismentioning

confidence: 99%

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

et al. 2017

J Therm Anal Calorim

“…The broad areas of application cover works based on cooling curve analysis of both nonferrous and ferrous alloys [11][12][13], and studies applying traditional methods such as TG-DSC-DTG to examine materials suitable for bonding agents in foundry purpose mould and core making technology [14,15]. Other works deal with the measurement of thermophysical properties in greensand moulds applying real foundry conditions [16][17][18]. In this study, the method of Fourier thermal analysis (FTA) was applied in an inverse way to interpret the heat distribution versus time curves recorded in the spherical samples.…”

Section: Results Of Fourier Thermal Analysismentioning

confidence: 99%

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

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).

“…Recently, studies applying traditional methods such as TG-DSC-DTG have been conducted to examine materials that are applicable as bonding agents in foundry purpose mold and core-making technologies [5]. Other sand-related works deal with the measurement of thermophysical properties in greensand molds while applying real foundry conditions [6,7].…”

Section: Introductionmentioning

confidence: 99%

Novel Measurement Method to Study Thermal Aspects of Molding Mixture Decomposition

2018

jcme

A wide variety of molding mixtures are extensively used in the process of the sand casting of metal components today. The sector is continuously developing in production volume; moreover, the expectations of customers are increasing on a monthly basis (also from a quality point of view). Even though mold and core manufacturing are well-organized routines in most foundries, technological problems still appear that can lead to technological problems and casting defects. These trends are forcing metal casters to come up with fitting strategies to solve their daily production challenges, while their suppliers are expected to keep up the continuous development of their existing foundry products and to find innovative solutions as well as new material combinations. Research on molding materials and their properties must, therefore, take a step forward accordingly to generate the necessary new knowledge to understand the behavior of mold and core mixtures during casting. This paper summarizes the latest results of a novel measurement method suitable for studying the degradation characteristics of different molding materials from a new perspective. The fundamentals of the method are based on a thermal analysis, focusing on the heat-absorption behavior of greensand and two types of chemically bonded sands regardless of the binder type and amount or the manufacturing process.