The paper presents the impact of the drawing method on the microstructure and corrosion resistance of galvanized steel wires. The microstructural tests confirmed that, in the drawing speed range v = 5–20 m/s, the use of hydrodynamic dies creates more favorable conditions for the deformation of the soft zinc coating on the hard steel core. The increase in friction at the wire/die interface in the conventional method, as compared to the hydrodynamic method, contributed to the decrease in coating thickness and the increase in the diffusion layer, and the higher the drawing speed, the greater the differences between the analyzed drawing methods. In the conventional method, while drawing at high speeds v = 20 m/s, there was a two-way diffusion and complete remodeling of the ζ phase in δ₁. In the hydrodynamic method, at the speed of 20 m/s, in the analyzed micro-areas, places showing the presence of the ζ phase, partially dispersed in the layer with pure zinc, were observed. A corrosion tests comparison between conventionally and hydrodynamically drawn wires showed an improved behavior of the latter. The greater mass in the surface layer of pure zinc, a substrate for the corrosion product in hydrodynamically drawn wires, reacted, creating insulation from the white corrosion produced. The compressive stresses in the hydrodynamic dies caused by the high pressure of the lubricant on the circumference of the wire closed the microcracks on its surface, which additionally sealed the zinc coating.

This paper describes research on the influence the technology of zinc-coated steel wire manufacturing has on the energy and force parameters of the drawing process, energy consumption and zinc expenditure. In the theoretical part of the paper, the theoretical work and drawing power were calculated. Calculations of the electric energy consumption have shown that usage of the optimal wire drawing technology results in a 37% drop in energy consumption, which in the course of a single year translates to savings equal to 13 TJ. This, in turn, results in the decrease of CO₂ emissions by tons and a total decrease of the eco-costs by approximately EUR 0.5 mln. Drawing technology also influences the losses of the zinc coating and CO₂ emissions. Properly adjusted parameters of the wire drawing technology allow obtaining a zinc-coating that is 100% thicker, translating to 265 tons of zinc, whose production generates 900 tons of CO₂ and incurs eco-costs equal to EUR 0.6 mln. Optimal parameters for drawing, from the perspective of decreased CO₂ emissions during the zinc-coated steel wire manufacturing, are as follows: usage of the hydrodynamic drawing dies, angle of the die reducing zone α = 5°, and drawing speed of 15 m/s.

The present work deals with polymer blends produced from poly(3-hydroxybutyrate), P3HB and polyurethane. Linear polyurethane (PU) was here synthesized by reacting polypropylene glycol with 4,4′-diphenylmethane diisocyanate, and was used in amounts of 5, 10 and 15 wt. %. The polymers were melt-mixed using a twin-screw extruder after prior premixing. The obtained blends were tested by differential scanning calorimetry analysis (DSC), Fourier transformation infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX). Their thermal and mechanical properties, including impact resistance, hardness, tensile and flexural properties, were also determined, and the surface topography and roughness were analyzed. FTIR analysis of the prepared blends confirmed the interactions of PU with the P3HB matrix via hydrogen bonding. Analysis of the surface topography of the samples showed that the higher the PU content, the greater the regularity and homogeneity of the surface structure. The roughness of the P3HB blend containing 5 wt. % PU was the greatest. SEM images of the fracture surfaces of the blend samples explain the mechanism of the improvement of their mechanical properties. The obtained polymer blends were characterized by significantly lower hardness, and better impact strength and relative elongation at break compared to native P3HB. The DSC results confirm a decrease in the glass transition, melting and crystallization temperatures with increasing amounts of PU in the blends. The lower melting temperature and the higher degradation temperature of the resulted blends than native P3HB make the processing conditions easier, and prevent the degradation of the material. The best mechanical and thermal properties were shown by blends containing 10 wt. % of PU.

This article presents research on the evaluation of the influence of various fiber laser parameters on the quality of the surface after the cutting process. The study was conducted using a 10 mm thick S355J2C+N steel sheet. The cutting process was performed on a Fiber Laser VFl530 cutting machine with a power of 4000 W, manufactured by Otinus. To develop a model of the laser cutting process, the response surface methodology (RSM) was applied. A second-degree polynomial equation was selected to construct the model. The study found that the parameter Rc exhibited a predicted coefficient of determination of 99.89% for the variance of laser settings in steel cutting, in relation to the roughness of the upper part of the intersection surface. The results demonstrated that the value of Rc is significantly influenced by cutting speed, the interaction between speed and peak power, the interaction between focus and speed, as well as the peak power parameter. Surface topography analysis revealed that as the laser beam power increased in relation to the cross-cutting speed, additional material melting occurred, leading to an increase in surface roughness. However, when the cross-cutting speed was increased while maintaining constant power, surface roughness decreased.

This paper presents a dimensional analysis of die castings made from AlSi12Cu1(Fe) alloy. The machining process was optimized to minimize downtime and equipment usage while maintaining product quality and production efficiency. The castings, shaped as hydraulic valves, were produced using a four-cavity die-casting mold. Due to difficulties in achieving the required geometric dimensions, each casting from a specific cavity was machined on separate Computerized Numerical Control (CNC) machines. This work focuses on the dimensional analysis of castings from each mold cavity and the optimization of the production process. Based on the analysis, it was observed that the castings could be divided into two distinct groups: the first group contained castings that, after machining, exhibited similar measurement values and remained within the specified dimensional tolerances, while the second group failed to meet the required tolerances. As a result of the conducted analysis, a new machining strategy can be proposed—assigning castings from each group to different CNC machines. This would eliminate the need for frequent machine retooling and significantly reduce production downtime. The findings point to a potential solution for optimizing the machining process and improving overall manufacturing efficiency.