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Incineration is currently the standard way of disposing of municipal waste. It uses components protected by high-temperature-resistant layers of materials, such as Inconel alloys. Therefore, the objective of the current paper is to study the mechanical properties and structure of a bimetallic Inconel 625-16Mo3 steel tube. The Inconel 625 layer was 3.5 mm thick and was applied to the surface of the tube with a wall thickness of 7 mm via the cold metal transfer method. The bimetallic tube was bent using a supercritical bend (d <= 0.7D). This paper is focused on the investigation of the material changes in the Inconel 625 layer areas influenced by the maximum tensile and compressive stresses after the bend. The change in layer thickness after the bend was evaluated and compared to the non-deformed tube. In addition, the local mechanical properties (nanohardness, Young modulus) across the indicated interfacial areas using quasistatic nanoindentation were investigated. Subsequently, a thorough microstructure observation was carried out in areas with maximum tensile and compressive stresses to determine changes in the morphology and size of dendrites related to the effect of tensile or compressive stresses induced by bending. It was found that the grain featured a stretched secondary dendrite axis in the area of tensile stress, but compressive stress imparted a prolongation of the primary dendrite axis.

This paper investigates surface state after turning of the high tempered bearing steel 100Cr6 with a hardness of 40 HRC. White layer (WL) thickness and its microhardness, as well as surface roughness, are investigated as a function of tool flank wear VB as well as cutting speed v(c). The mechanical and thermal load of the machined surface were analysed in order to provide a deeper insight into their superimposing contribution. Cutting energy expressed in terms of cutting force was analyses as that consumed for chip formation F-gamma and consumed in the flank wear land F-alpha. It was found that the mechanical energy expressed in terms of the shear components of the F-alpha grows with VB, converts to the heat and strongly affects the thickness of the re-hardened layer. Furthermore, the superimposing contribution of the heat generation and its duration in the VB region should also be taken into account. It was also found that the influence of VB predominates over the variable cutting speed.

In this paper, the microstructural damage evolution of a steel with a ferrite-pearlite microstructure (C45E) was investigated during the process of cold upsetting. The development and the accumulation of microstructural damage were analyzed in different areas of samples that were deformed at different strain levels. The scanning electron microscopy (SEM) results showed that various mechanisms of nucleation of microcavities occurred during the upsetting process. In quantitative terms, microcavities were predominantly generated in pearlite colonies due to the fracture of cementite lamellae. In addition, the mechanism of decohesion had a significant influence on the development of a macroscopic crack, since a high level of microcracks, especially at higher degrees of deformation, was observed at the ferrite/pearlite or ferrite/ferrite interfaces. It was found that the distribution of microcavities along the equatorial plane of the sample was not uniform, as the density of microcavities increased with increasing strain level. The influence of stress state, i.e., stress triaxiality, on the nucleation and distribution of microcracks, was also analyzed.

Aluminum is a widely popular material due to its low cost, low weight, good formability and capability to be machined easily. When a non-metal such as ceramic is added to aluminum alloy, it forms a composite. Metal Matrix Composites (MMCs) are emerging as alternatives to conventional metals due to their ability to withstand heavy load, excellent resistance to corrosion and wear, and comparatively high hardness and toughness. Aluminum Matrix Composites (AMCs), the most popular category in MMCs, have innumerable applications in various fields such as scientific research, structural, automobile, marine, aerospace, domestic and construction. Their attractive properties such as high strength-to-weight ratio, high hardness, high impact strength and superior tribological behavior enable them to be used in automobile components, aviation structures and parts of ships. Thus, in this research work an attempt has been made to fabricate Aluminum Alloys and Aluminum Matrix Composites (AMCs) using the popular synthesis technique called stir casting and join them by friction stir welding (FSW). Dissimilar grades of aluminum alloy, i.e., Al 6061 and Al 1100, are used for the experimental work. Alumina and Silicon Carbide are used as reinforcement with the aluminum matrix. Mechanical and corrosion properties are experimentally evaluated. The FSW process is analyzed by experimentally comparing the welded alloys and welded composites. Finally, the best suitable FSW combination is selected with the help of a Multi-Attribute Decision Making (MADM)-based numerical optimization technique called Weighted Aggregated Sum Product Assessment (WASPAS).

This paper deals with material and dimensional bending analysis of bimetallic pipes with defined bending radii. Basic characteristics of selected nickel superalloys with analysis of Inconel 625 and 16Mo3 steel in terms of primary mechanical properties and chemical composition are presented. The practical part where the bimetallic tube is analyzed in terms of material properties is also performed geometric dimensional analysis, for which test specimens with different bending radii are made., Předložený příspěvek se zabývá materiálovou a rozměrovou analýzou bimetalového trubkového oblouku s definovanými poloměry ohybu. Teoretická část příspěvku byla zaměřena na základní charakteristiku vybraných niklových superslitin s rozborem materiálu Inconel 625 a oceli 16Mo3 z pohledu primárních mechanických vlastností a chemického složení. Praktická část příspěvku charakterizuje bimetalový trubkový oblouk s prodlouženými konci s ohybem 1D z hlediska materiálových analýz, zejména analýzy chemického složení, struktury materiálů, mikrotvrdosti a přítomnosti trhlin.

Unconventional methods of modern materials preparation include additive technologies which involve the sintering of powders of different chemical composition, granularity, physical, chemical and other utility properties. The technology called Rapid Prototyping, which uses different technological principles of producing components, belongs to this type of material preparation. The Rapid Prototyping technology facilities use photopolymers, thermoplastics, specially treated paper or metal powders. The advantage is the direct production of metal parts from input data and the fact that there is no need for the production of special tools (moulds, press tools, etc.). Unused powder from sintering technologies is re-used for production 98% of the time, which means that the process is economical, as well as ecological., K nekonvenčním moderním metodám přípravy materiálů patří zejména tzv. aditivní technologie, které zahrnují slinování prášků různého chemického složení, zrnitosti, fyzikálních, chemických i jiných užitných vlastností. Do této oblasti přípravy materiálů se řadí tzv. technologie Rapid Prototyping (RP), které využívají různých technologických principů ke zhotovení součástí. Podle použité technologie se v zařízeních Rapid Prototyping používají fotopolymery, termoplasty, speciálně upravený papír nebo kovové prášky. Jejich velkou výhodou je přímá výroba kovových dílů ze vstupních dat a dále fakt, že odpadá potřeba výrobního nářadí (forem, lisovacích nástrojů, atd.). U technologie práškového spékání je nespotřebovaný prášek z 98% znovu využíván pro výrobu, tzn. že proces je ekonomický a zároveň ekologický.