At present, much attention is focused on developing clothing fabrics with advanced functionality without compromising their visual, mechanical, or comfort properties. A fabric’s ability to prevent the penetration of electromagnetic radiation is an interesting added feature. In the published literature, there are many references describing the development and investigation of electromagnetic shielding textile structures using different electrically conductive additives. However, little attention has been given to the aesthetic and comfort properties of these special fabrics. Moreover, the availability of everyday fashion containing electromagnetic radiation protection is very limited. For this study, woven fabric made from a mixture of traditional fibers and extremely thin discrete stainless steel fibers developed in the authors’ previous research was used as a substrate. The fabric was digitally printed to provide an interesting design effect suitable for use in clothing and for making clothes for everyday wear. The main objective of this work is to determine whether digital printing is a suitable tool for changing the color and pattern of this metal fiber-containing fabric. The individual goals are (a) to examine the fabric’s color fastness to washing and (b) to investigate whether the surface modification of the fabric adversely affects its functionality. Results show that it is possible to change the color and pattern of metal fiber-containing fabric by digital printing easily, whereas the associated decrease of porosity causes an increase of this special fabric functionality. The electromagnetic shielding effectiveness of the fabric after printing is around 33 dB for frequency 1.5 GHz. However, washing has a negative effect, causing both the electromagnetic shielding ability decrease (to 27 dB for frequency 1.5 GHz after 20 washing and drying cycles) and color fading (the color fastness grade is around 1–2 after 20 washing and drying cycles). Furthermore, the basic transport properties of printed electrically conductive fabric are compared with those of fabric made from traditional material and positive results are found. The incidence of pilling after washing is also evaluated, whereas the first pills are observed after the eighth washing and drying cycle. Finally, clothing prototypes that could be prepared from printed fabric are presented.

Steels which are utilized in the manufacturing of specific parts of military technology such as crankshafts of engines in heavy-duty vehicles or barrels of guns must be subsequently modified by heat treatment according to the requirements of customers. Despite the hard surface of martensitic structure obtained by hardening process, steels have a low wear resistance and high values of coefficient of friction. To improve these parameters and due to the fact that many of steels which are utilized for manufacturing of mentioned parts are also categorized as Nitralloy steels, in this paper, the improvement in these properties of chosen steels by the application of plasma nitriding has been studied. The steel equivalent 17Ni4CrMo (i.e., CSN 41 6720) and equivalent 42CrMo4 (i.e., CSN 41 5142) were chosen for the study. The chemical composition of chosen steels was verified by optical emission spectrometry. The microstructure and the diffusion layer were observed by optical microscopy due to the evaluation of layer parameters important for the lifetime. ZWICK ZHU 2.5 was used for a measurement of the universal hardness of the surface and values of graphs of microhardness were obtained by the device LM 247AT LECO from a cross-section of samples. The coefficient of friction was determined by Bruker CERT-UMT-3 with a ball-on-disc method. The parameters of wear paths were obtained by Talysurf CLI 1000. After the application of plasma nitriding technology, the hardness of both steels was rapidly increased in comparison with non-nitrided samples. According to the comparison of coefficients of friction with respect to the parameters of the measurement, the coefficient of friction of nitrided samples decreases with increasing temperature, which is essential knowledge for the weapon industry, especially the construction of bore barrel.

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The current development of chemical-heat treatment technologies is aimed at increasing the utility properties of components and improving the quality of the produced surface. A prerequisite for a quality produced surface is the selection of a suitable method of surface machining before the application of chemical-heat treatment technology. Due to the requirements for functional areas of special technology, grinding is chosen in most cases. The present paper deals with the effect of nitriding in plasma and gas on the geometric accuracy of parts made of 42CrMo4 steel. This steel is widely used in special technology for the production of barrels, breech-block cases, ball screws and gears. On the ground steel samples, the 3D measurement on the coordinate measuring machine analyzed the change of dimensions after the application of nitriding in plasma and gas. Furthermore, the surface texture change was evaluated using 2D surface roughness parameters and 3D parameters of area. After nitriding in both plasma and gas, the dimensions increased by 0.034 mm in diameter. After the nitriding processes, the values of 2D and 3D surface roughness parameters decreased. A change in surface texture was observed when evaluating 3D parameters in both chemical-heat treatment processes. Increasing the dimensions and changing the texture of the surface affects the subsequent function of the components.

Nitriding is a technology that leads to an increase in the utility value of the product. It's most important benefits include increased corrosion resistance, abrasion resistance, wear resistance, increased resistance to fatigue failure under cyclic loading, and many others. The design of a suitable nitriding technology not only on the basis of empirics requires a closer study of the relationship between the structure of the nitriding layer, its properties and the course of a particular degradation process. Because the life of most components is related to abrasion on the surface, the occurrence of fatigue cracks and corrosion effects, it is crucial to influence the mechanical and other properties in this surface area. High functional requirements are placed on the functional surfaces of steels for weapons production, which lead to a long service life, reliability and dependability of the components of the weapon system and its safe use. The paper discuss the influence of selected nitriding technologies on the mechanical properties of steel 42CrMo4 and 34CrNiMo6, especially on the hard and microhardness of surface layers, change of its structure and next to change the surface texture and dimension of component. The steels were nitrided in plasma and gas. Nitriding in gas led to more significant structural changes in the surface layer of both steels compared to plasma nitriding.