Ján Moravec

This study is focused on the unwrapping contribution of microstructure (mainly expressed in terms of dislocation density) and stress state in the quenched bearing steel 100Cr6. Microstructure as well as residual stress state alterations are developed only as a function of variable infeed rates in the flat plunge grinding (other grinding conditions are kept constant). The study is also dealing with the synergistic contribution of residual stress state and the superimposing elastic external stress developed during bending. It was found that the Barkhausen noise after grinding is mostly a function of the thermal softening, whereas the role of residual stress state is only minor. The growing Barkhausen noise emission at the lower infeed rates is connected with the compressive stress, and the tensile stresses are developed at the higher removal rates only. The study also demonstrates good sensitivity of Barkhausen noise when this emission is descending along the compressive external stresses and the ascending evolution along the tensile stresses when the magnetic field is altering along the direction of exerted stress. On the other hand, this evolution is reversed when the altering magnetic field is altered along the transversal direction.

The article provides the necessary information about the AlCu4MgTi alloy. This alloy appears to be a promising material for industrial use. The article not only publishes theoretical knowledge and data, but also describes and presents the results of experiments with the alloy. The analysis of the material is supplemented by metallography.

The article focuses on the issue of adjusting deviation meters using adjustment rings. The text provides general information and also the manufacturing process of these rings. Measuring rings are suitable for applications in small-scale production.

Operation of vehicle–trailer combinations is currently popular throughout many countries. Connecting a trailer to a passenger car increases the car’s utility value because it is possible to transport more goods over shorter or longer distances. Trailers are also popular as caravans, which provide a home on wheels during holiday periods. As a trailer is connected to a towing vehicle by means of a spherical joint from the mechanics’ point of view, a vehicle–trailer combination has significantly different driving properties in comparison with a sole vehicle. These differences are manifested mainly while driving in a curve as lower stability of the vehicle. In this case, the lower stability is considered an uncontrolled sway motion. This study is focused on researching the driving stability of a vehicle–trailer combination regarding the sway motion problem. The research is fully performed by means of simulation computations in a commercial multibody simulation software. The investigated vehicle–trailer combination consists of an SUV passenger car and a single-axle goods trailer. Two model driving maneuvers are investigated, namely bypassing an obstacle in a lane and changing lanes on a road. Simulation computations are performed for chosen loads of the trailer and for a different position of the center of gravity of the load in the single-axle trailer. The performed research has proven that the applied simulation computations represent a robust tool to investigate real tasks related to vehicle safety without performing expensive and dangerous tests. Very important findings include identifying the proper position of the center of gravity of the load on the trailer to ensure safe driving properties for driving maneuvers that could pose potential danger during real operation.

This study investigates the evolution of strain-induced martensite (SIM) and its effect on magnetic Barkhausen noise (MBN) in AISI 321 austenitic stainless steel subjected to uniaxial tensile testing. Using X-ray diffraction and the Barkhausen noise technique, the formation and distribution of SIM were analysed as functions of plastic strain and strain rate. The results show that MBN is primarily governed by plastic deformation and strain rate rather than residual stress. The martensite fraction increases from 10% at low strains to 42.5% at high strains; however, accelerated strain rates significantly reduce martensite formation to approximately 25%. The increase in martensite density enhances the magnetic exchange interactions among neighbouring islands, resulting in stronger and more numerous MBN pulses. The anisotropy of MBN is also influenced by the initial crystallographic texture of the austenite. These findings highlight the strong correlation between MBN and SIM evolution, establishing MBN as a sensitive, non-destructive tool for assessing martensitic transformation and optimising deformation parameters in austenitic steels.

The article focuses on explosive forming of metals, in this case pipes, where the text provides the necessary information about the process of this type of forming. In the second part, based on knowledge from the theory of metal forming, a theoretical analysis of the process is given.

The presented contribution focuses on the field of manual metal processing using filing technology. Knowledge about the production of files, the geometry of file teeth are presented. Some selected findings from the subject area are presented.

The paper analyzes an unconventional method of forming sheet metal parts with high energy release. Published diagrams and images together with a physical description of the process illustrate how this technology can be applied to form large-sized sheet metal parts at low production costs. The text presents important mathematical equations that are part of the physical description together with technological parameters. A brief economic evaluation is presented in the conclusion.

The paper focuses on the issue of shear wear. Theoretical foundations are presented and an analysis of the issue of sharpening the active parts of the shear tool is also described. Sharpening the shears themselves is an important part of repairing shear tools and their required starting position before setting them on the press.

The presented paper discusses the issue of the possibility of forming metals using hydraulic shock. The first part of the text presents the necessary theoretical knowledge about the issue. The second part presents some solutions of this advanced metal forming technology.