The article addresses stress formation in the structural 3D-printed elements of a high-pressure die casting die mould used for production of aluminum castings. The 3D-printed elements with conformal cooling are manufactured of 18Ni300 powder. Initial numerical calculations were performed on a test die mould made of standard steel X40CrMoV5 to determine temperature distribution and stress state, providing a baseline for comparing 3D-printed 18Ni300 parts. A database for 18Ni300 material was developed, including optimal heat treatment parameters: aged at 560 °C for 8 h. The resulting tensile strength of approximately ~1600 MPa, yield strength 1550 MPa, and elongation 6–7%, with properties temperature-dependent from 20 °C to 600 °C. Results show that conformal cooling increases stress gradients, highlighting the demands on fatigue strength at elevated temperatures. The study revealed that the heat treatment significantly influences the final properties, with tensile strengths of 1400–2000 MPa and elongation from 1 to 8%. While the heat treatment has a greater impact on the mechanical properties than the printing parameters, optimizing the printing settings remains crucial for ensuring density and quality in the die moulds under cyclic loads.

The article presents the optimization of high-pressure die casting process technology for equestrian stirrups with the application of computer simulation. In the initial stage, the output technology was analyzed, and on the basis of a series of virtual experiments the cause of defects in the casting was highlighted. The optimization process includes different designs of a gating system. Additionally, the casting application properties were evaluated in an exploitation simulation, taking into account predicted defects resulting from the casting and solidification process. Based on the conducted analyses, technological changes were made to the casting technology design allowing the defects occurring in the original technological concept to be removed.

Increased wear of drive wheel teeth in a longwall shearer requires frequent replacement of this expensive component, due to use of high power drives and geometrical limitations to the advance systems. A concept of the innovative Flextrack advance system, which enables limiting the high pressing stresses between cooperating surfaces of drive wheel and tooth gear (according to Hertz), was developed. The tooth gear, which consists of single segments, each with only one tooth, is the main component of Flextrack advance system. The sidewalls of the tooth gear have tacks of spherical shape located on the surfaces of the segments cooperating with each other. This design causes that the segments can be “seated” against each other, with no need to change the pitch between the teeth. The surfaces of tracks of tooth gear segments can incline transversely and longitudinally, and it is limited only by a special guide. The advance tooth gear system made in such way enables one to overcome horizontal and vertical inclinations of the conveyor route on which the shearer moves. The material model accepted for numerical analyses assumed the use of high strength spheroidal cast iron EN-GJS-1200-2 and L20HGSNM cast steel. The manufacture of casts of tooth gear segments in a precise casting technology enables one to obtain high accuracy of cooperating spherical surfaces as well as surfaces of the flank of the tooth cooperating with drive wheel. Accepted casting technology ensures high repeatability and the reduction of the cost of a single tooth gear segment, assuming serial manufacture. Changes applied to the design of advance system will increase the operational life of drive wheels, significantly reducing the maintenance time in very dangerous conditions.

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.

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 article discusses the weldment to casting conversion process of rocker arm designed for operation in a special purpose vehicle to obtain a consistency of objective functions, which assume the reduced weight of component, the reduced maximum effort of material under the impact of service loads achieved through topology modification for optimum strength distribution in the sensitive areas, and the development of rocker arm manufacturing technology. As a result of conducted studies, the unit weight of the item was reduced by 25%, and the stress limit values were reduced to a level guaranteeing safe application.