Thise research was conducted to determine the impact of the applied casting technology, mould and alloying additives on the tightness of the CuSn10 cast alloy. Under industrial conditions, a series of experimental melts were made that were characterised by varying the concentrations of the main alloying element (Sn) and the introduced alloying additives (Si, Zn, Zr). The mould was made from green sand and used the CO₂ moulding process. To assess the influence of the alloying additives, a metallographic analysis of the studied alloy was carried out, and the alloy’s microstructure was examined using optical and scanning electron microscopy. The introduced alloying additives affected the properties and microstructure of the studied alloy. As alloying additives, zirconium resulted in a visible refinement of the microstructure, while silicon improved the fluidity and quality of the casting’s external surface. The use of alloying additives and moulds made using different technologies is intended to improve the structure of the tin bronze castings produced and to find the best solution to significantly eliminate the lack of leakage of the castings. The castings were subjected to mechanical processing, and a leak test was performed using the pressure drop method. The conducted research allowed us to determine which technology, applied to production, will bring about a reduction in the problem and will inform further investigations.

This article presents some views on the subject of self- or residual stresses, trying to clarify some erroneously seemingly ingrained formulations in the introduction, which are widely used in castings and their classification (thermal, shrinkage, and phase stresses). For example, the location of their occurrence is often not specified, nor in which cross sections (volumes) they balance. In thin bars there are uniaxial stresses and in thin plates, stresses in two orthogonal directions are considered, while in castings, which are always three-dimensional objects, stresses in all planes should be considered. Meanwhile, to make matters worse, the complexity of calculations and possible experiments is rapidly increasing from the 1-axis to the 3-axis condition. A detailed analysis is made of how tensile and compressive stresses are calculated as a function of casting wall thickness, taking into account heat flow between walls of different thicknesses. The article presents selected methods of stress and strain testing, with particular emphasis on elasto-optical testing.

• Theory and practice of environmental protection in the case of foundries in Europe and Asia • Experience resulting from the cooperation with the foundries in a few European countries, China and India • Phenomena and factors affecting the pollution of the natural environment and the implementation of measures aiming at the environmental protection. Every specialist dealing with foundry processes and their impact on environmental pollution must have encountered in their professional careers numerous situations in which the theory of environmental protection confronts the stark reality. The discrepancy between theory and practice can particularly be noticed in foundry engineering in developing countries where the contrasts between different countries and casting plants are extremely striking. The comparison of working conditions in European and Asian foundries provides a vast scope for further observations and analyses. Environmental protection seems not only a concern of manufacturers of castings, but also of their customers whose opinion exerts a significant influence on both the acceptability of working conditions and on the approach to environmental pollution adopted in metal casting industry. The article presents a number of examples of various outlooks on environmental issues in foundries manufacturing a wide range of cast steel and cast iron castings, where different technologies and production processes are applied.

Rapid development of the methods of additive manufacturing (AM) introduces a number of changes to the design of foundry equipment. AM methods are of particular importance in the development of technology to make small lots of castings or single cast items of complex shapes, such as skeleton castings manufactured also by means of other technologies [1]. AM methods create the possibility of making single-use moulds, cores and wax patterns, as well as patterns made from plastics for repeated use. The development of AM techniques gives theoretically unlimited possibilities in the choice of the designed casting configurations. This fact can be used during the analysis of casting mechanical properties based on the methods of topology optimisation [2], [3], [17], when the said optimisation carried out at the initial stage of design ”matches” the shape of parts to the field of stresses or displacements caused by external load and fixing mode. The article discusses the possibilities and advantages that result from combining the new methods of shaping the casting endurance with AM technologies.

The article presents the analysis of properties of the high-strength AlZnMgCu (abbr AlZn) aluminium alloy and estimates possibilities of its application for responsible structures with reduced weight as an alternative to iron alloy castings. The aim of the conducted studies was to develop and select the best heat treatment regime for a 7xx casting alloy based on high-strength materials for plastic working from the 7xxx series. For analysis, wrought AlZnMgCu alloy (7075) was selected. Its potential of the estimated as-cast mechanical properties indicates a broad spectrum of possible applications for automotive parts and in the armaments industry. The resulting tensile and fatigue properties support the thesis adopted, while the design works further confirm these assumptions

The development of a novel design for the toothed segment of drive transmission in longwall shearer is expected to significantly reduce the cost of individual components of the feed system and the related work of repair and renovations, increasing at the same time the safety of mine repair teams. The conducted experimental and numerical analysis of the state of stress and strain in the innovative design of the toothed segment has enabled estimating the maximum effort of the developed structure. Based on the results of fundamental mechanical studies of the cast L20HGSNM steel and fatigue tests combined with the numerical stress/strain analysis, the fatigue life curve was plotted for the examined casting of the rack.