Since its inception in 1994 in Smolenice, Slovakia, the High TemperatureCapillarity (HTC) conference has been held approximately every three years.After the pandemic around 2020, the conference has been held every two years,with an online conference in Hungary in 2020 and in Kraków, Poland, in 2022.Initially, the primary focus was on capillary phenomena at high temperatures,but in recent years, discussions have expanded to encompass a broader rangeof interfacial phenomena, thermophysical properties, and related topics.The 11th International Conference on High Temperature Capillarity (HTC2024) was hosted in Sweden, taking place in Stockholm and aboard a cruiseship traveling between Stockholm and Helsinki. This was the first time thisesteemed conference was held in Sweden and also the first instance of itbeing conducted in such a unique setting. It is our belief that this remarkableexperience will leave a lasting impression on all participants.

The aim of the present study is to elucidate the influence of individual microstructural parameters, such as pearlite fraction, nodularity, and eutectic cell size, on the tensile strength (UTS) of cast irons. The UTS model was built by integrating the rule of mixtures for each microstructural component, and the UTS was described as a function of the aforementioned factors. The UTS and the required microstructure parameters for the model calculation were obtained experimentally. In the model, two coefficients were introduced to quantify the influence of the eutectic cell size and the interaction terms for the mixed two components. These coefficients were determined through fitting the experimental data, and the model's accuracy was validated using data not included in the fitting process. The results exhibited reasonable agreement, confirming the model's reliability. The model, thus, offers insights into the influence of each microstructural factor on UTS and serves as a guide for designing alloys to achieve the desired UTS through microstructure modifications.

Thermal conductivity is an important property for cast components produced from different types of cast iron. Development of a general widely-accepted thermal conductivity model for compacted and lamellar graphite irons poses a research challenge. The present study extends the modeling approach introduced earlier for pearlitic lamellar graphite iron toward compacted graphite iron and ferritic lamellar graphite iron. The proposed thermal conductivity model of the bulk material is based on the alloy microstructure and Si segregation between eutectic cells and non-cell regions, at the main assumption that the heat paths in the eutectic cells are formed by connected graphite phases surrounded by ferrite phases. The overall thermal resistance of these heat paths is determined by the hydraulic diameter of the interdendritic region. The uncertainties both for the modeled and for experimentally derived thermal conductivities have been estimated. The importance of considering the Si segregation in the model has been discussed. For the investigated samples, the agreement between modeled and measured thermal conductivities has been achieved within 4% on the average, at the same value of the single fitting parameter found for pearlitic, pearlitic–ferritic lamellar, and compacted graphite iron alloys. The results contribute to the understanding of the material microstructure effects on the cast iron thermal conductivity.

Over the past decades, demand for high-purity aluminium (Al) has increased in many sectors, like aerospace and automotive sectors, since it combines a high level of purity with the flexibility of controlled alloying, which allows for tailored enhancements of material properties. To accommodate the rising demand, primary Al production has significantly increased since the refining of secondary Al is constrained by high impurity levels, especially iron (Fe). A way to mitigate this problem is to add Fe-bearing intermetallic particle formers, like manganese (Mn). This paper investigates the influence of different Mn additions for low-Fe composition aluminium melts at a cooling rate of 3 °C/min, as the primary Fe-rich phases may differ and cannot be extrapolated. More specifically, the impact of filters, the Fe removal efficiency for different Mn additions, and the Fe-bearing intermetallic particles’ Fe removal potential. Fe removal potential was evaluated by combining intermetallic particle area fraction with their average Fe content. This was done by running Thermo-Calc equilibrium calculations to guide the planning of the experimental work. Then, running small-scale experiments with 8 kg of Al-11Si-0.5Fe alloy. The study concludes that the Fe-bearing intermetallic parties sedimented at the bottom of the furnace since the composition of the filtered and unfiltered samples from the top part of the melt was similar. Additionally, larger amounts of Mn are required to improve the Fe removal efficiency for low-Fe concentration Al-Si cast alloys since it improves the Fe removal potential and increases the amount of Fe-bearing intermetallic particles in the melt.

Silica sand is extensively used as a moulding sand for both mould and core making in the cast iron and steel casting industries. The pouring temperatures of cast iron and steel create a nonlinear distribution of temperatures across mould/core. The temperature fluctuations in mould/core establish different heat transport zones and result in a temperature-dependent undesirable expansion of silica. The expansion of silica is one of the primary sources for the formation of surface defects on castings. Additives are incorporated to mitigate the volumetric expansion of mould/core resulting from the granular expansion of silica sand. The paper aims to investigate the thermal dilation of unbonded silica sand integrated with different amounts of additive in the sand (0.8%, 1.0%, and 1.3%) using a horizontal dilatometer. The dilatometric investigations identified a decreasing trend in the thermal expansion behaviour of silica mixture with increasing content of additive inclusions in the mixtures. In theory, the additives in the sand mixtures decompose prior to the α↔β endothermic phase transition of quartz and provide intergranular spacing for the free expansion of silica. DSC and TGA were conducted to identify the phase change in silica and the degradation.

A simulation methodology has been developed and experimentally validated, including a simplified three-dimensional finite-element heat transfer model of the laser surface cladding/alloying process. Cladding/alloying of a nickel-based superalloy powder on grey cast iron substrate has been studied. By introducing and estimating a power scaling factor, it has been shown that the model is capable for prediction of the penetration depth into the substrate, heat-affected zone size and dilution ratio at various laser powers, based on a single laser cladding/alloying experiment to deliver the model input and data for comparison.

The primary objective of this study is to explore the impact of temperature and magnesium addition on the partial oxygen potential in lamellar, compacted, and spheroidal cast irons during the cooling process. The oxygen potential is assessed in large-scale plant trials with a 1000 kg scale. Thermodynamic calculations are conducted, and the results are compared with the experimental values. There is a reasonable agreement between the experimental and calculated values, facilitating the prediction of oxygen potential in temperature ranges where measurements are challenging. According to the thermodynamic calculations, it is observed that varying amounts of added magnesium result in the formation of different types of inclusions during cooling. This, in turn, influences the temperature dependency of the oxygen potential in the molten metal.

Interfacial phenomena occur when two immiscible liquids contact each other, and they are of interest in various scientific and technological fields. Understanding and observing the interfacial phenomena between molten oxide and liquid iron (Fe) is crucial for process control in steel manufacturing. We study interfacial phenomena by observing the surface oscillation of compound droplets comprising molten oxide and liquid Fe in the electrostatic levitation furnace (ELF) aboard the International Space Station. Compound droplets form core-shell droplets under microgravity conditions due to the absence of density differences. During onboard experiments using the ELF, we created core-shell compound droplets comprising molten oxide (SiO2:CaO:Mn3O4:TiO2:Fe2O3 = 25:7:20:18:30 mass%) and liquid Fe in an Ar atmosphere. We observed increased droplet volume while observing the core-shell droplet oscillation phenomena at constant temperature. This expansion can be attributed to the dissolution of Fe from the core liquid to the shell molten oxides at the interface due to the oxidation of liquid Fe. It is necessary to investigate the volume changes of the core-shell droplet to clarify the hypothesis. We analyzed the volume change using the measured density of molten oxide when Fe was dissolved into the molten oxide using the aerodynamic levitation method on the ground. Through these analyses, we discuss the oxidation of liquid Fe at the interface with the molten oxide.

Thermal conductivity is an important property for many iron cast components, and the lack of widely accepted thermal conductivity model for cast iron, especially grey cast iron, motivates the efforts in this research area. The present study contributes to understanding the effects alloy microstructure has on thermal conductivity. A thermal conductivity model for a pearlitic cast iron has been proposed, based on the as-cast alloy composition and microstructural parameters obtained at different solidification rates. According to the model, available parallel heat transfer paths formed by connected graphite flakes across eutectic cells are determined by the space between dendrite arms. The uncertainties both for model inputs and for validation measurements have been estimated. Sensitivity analysis has been conducted to result in better understanding of the model behaviour. The agreement between modelled and measured thermal conductivities has been achieved within 5% on the average for the investigated samples.