Binder Jetting technology is well established for the production of sand molds and cores for foundry use, owing to its flexibility and expansive design capabilities. A wide array of sand, aggregate, and binder combinations is commercially available. Utilizing these types of refractory materials in the casting process presents both technical and economic benefits and drawbacks. For intricate cast components, foundry technologists must assess the thermophysical properties of the mold material systems. With this knowledge, specialized high-performance material combinations may be employed in specific areas of the mold, while more economically viable systems are used for shaping the external mold support. This study primarily focuses on determining the heat capacity and thermal diffusivity and consequently the thermal conductivity using a specially developed analytical method. It investigates three different fundamental aggregates: silica, cerabeads^®, and chromite. The result’s range provides an overview of relevant characteristics for the selected material systems. Given that the properties of sand affect heat flow during casting and solidification, these newly determined values can be utilized in future simulations. Consequently, these findings aid in maintaining and enhancing the quality of critically stressed cast parts.

In view of the increasing demand for secondary aluminum, which is intended to partially replace the very energy- and resource-intensive primary aluminum production, effective treatment methods can maintain the high quality level of light metal castings. The transition from a linear to a circular economy can result in an accumulation of oxides or carbides in aluminum. Therefore, melt purification is crucial, especially as foundries aim to increase the use of often dirty end-of-life scrap. Nonmetallic inclusions in the melt can impact its flowability and mechanical properties. As the purity of the melt increases, its flow length also tends to increase. Available assessment methods like reduced pressure test or K-mold are capable of ensuring high levels of purity. This study demonstrates the implication of inclusions originating from dirty scrap. An experimental test run deals with various scrap contents in an AlSi7Cu0.5Mg alloy and shows correlations between impurity and performance, expressed by flowability and mechanical properties. These performance indicators have been connected to inclusion and porosity rates. In conclusion, these findings emphasize the need for further extensive research on contaminants in the field of scrap melting and the development of methods for easy-to-handle assessment methods.

With increasing use of secondary material certain alloying elements may accumulate over repeated melting cycles. To determine the influence of Fe, Mn, Cu and Zn on the technological properties of AlSi7Mg0.3 cast alloy three compositions with varying additions of these elements to a primary alloy melt were produced. Gravity die-casting experiments using a tensile sample permanent mold were conducted, and the cast samples ran through a heat treatment to achieve practical properties. All samples passed through X-ray analysis to minimize the influence of defects on mechanical properties. Specimen for mechanical testing, microscopic analysis and corrosion tests were taken from the cast samples. Quasi-static mechanical properties were measured via tensile and hardness testing, whereas dynamic mechanical properties were determined with high-speed tensile tests. Furthermore, various cyclic fatigue tests are conducted to derive comprehensive S–N curves for each composition. A small increase in R _{p 0,2} (YS) but a clear decrease in A ₅ (Elongation) for quasi-static, as well as for dynamic tensile tests is detected with higher Fe- and Mn-proportions. The further addition of higher amounts of Cu and Zn also affects the mechanical properties in a similar way, albeit at a lower scale. However, Cu significantly aggravates the corrosion properties, whereas no such effect could be detected for Fe and Mn. On the other hand, fatigue properties were not as strongly affected by higher Fe and Mn amounts. In total, the results of this study present a comprehensive overview of the effects that higher amounts of accumulating alloying elements have on the technological properties of AlSi7Mg0.3 cast alloy.