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Titanium alloys thanks to their low density and high mechanical properties are a group of materials that are being used willingly nowadays. A promising method of titanium heat treatment is laser alloying. Process parameters like laser beam power, its traverse speed, amount of alloying elements and shield gas, have influence on the resulting material. Different chemical composition and morphology can be achieved resulting in a change of properties on the surface of the material. The paper presents the investigation of titanium GRADE 1 processed with iron‐nickel powder using laser alloying. The treatment was performed using a high power diode laser. Different laser beam power values were used. Treatment resulted in obtaining good‐adhere, porous‐free, uniform composite material with no cracks. Formation of new phases and solid solution was the reason why it was possible to achieve an increase in microhardness on the surface. Light microscopy, scanning electron microscopy with energy dispersive X‐ray spectroscopy examination, microhardness results and X‐ray diffraction are presented within the paper. [ABSTRACT FROM AUTHOR]

Abstract: In recent years, increasing interest in the improvement of the mechanical properties of aluminum‐magnesium alloys has been shown. However, it is known that the addition of magnesium result in a workability decrease. For this reason, it is necessary to find a way to enhance the ductility of aluminum‐magnesium alloys before plastic working. The present study shows that the plasticity of the AlMg5 aluminum alloy can be increased through a solution treatment. However, even after heat treatment, only 2 passes were possible to perform. For this reason, the increase of the workability was achieved by application of the inter stage annealing at 350 °C for 30 min. It was found that there is a possibility to obtain a fine grained bimodal structure of the as annealed material through the partial recrystallization and increase in workability of the severe plastic deformed material. It was also found that further plastic deformation results in obtaining a material with greater mechanical properties (hardness and tensile strength) in comparison to a material without inter pass annealing. To characterize the structure evolution of the material at different stages of treatment, light and electron microscopy was used. [ABSTRACT FROM AUTHOR]

The results of the present investigation are focused on the structure examinations of a commercial Al-3%Mg alloy in different conditions using an optical microscope (OM), scanning electron microscopy (SEM), the EBSD technique, transmission electron microscopy (TEM) and X-ray diffraction (XRD). Measurements of the microhardness and ultimate tensile strength were carried out to evaluate the influence of ECAP and post-ECAP treatment on the mechanical properties. In this study, we found that 6 ECAP passes via route B c result in a significant grain refinement. The measured average grain size of the as deformed sample was about 0.43 μm. As a result of the performed post-ECAP heat treatment (artificial ageing), a material with a more homogenous microstructure, having an average grain size of ~ 0.68 μm, was obtained. The results of the mechanical property measurements show a significant increase in mechanical strength to about ~ 384 [MPa] in the T9 condition and to ~ 330 [MPa] after post-ECAP treatment (T8 condition). The high strength of the alloy in the T9 condition is suggested to be related to grain size strengthening, dislocation strengthening and precipitation strengthening. An increase in elongation/ductility from 2.4% to 11.2% was observed in the T8 condition sample, which is a result of the grain growth and the dislocation density decrease. [ABSTRACT FROM AUTHOR]

In the present work, the effect of severe plastic deformation (SPD) on the mechanical properties of two binary Al−Mg alloys have been investigated. Because of the limited workability of the investigated material, both alloys were subjected to the heat treatment (precipitation treatment) before plastic deformation using equal channel angular pressing (ECAP). Results of investigation show that the increased magnesium content result in a decrease in workability, however, the heat treatment improves ability for plastic working. It was also observed that a combination of heat treatment with severe plastic deformation causes an increase in mechanical properties when compared to the initial material. In order to characterize structural changes that occur after plastic deformation, scanning electron microscopy and transmission electron microscopy were used. [ABSTRACT FROM AUTHOR]

The presented investigation results were carried out on two binary aluminium-magnesium alloys. The article focuses on the influence of heat treatment conditions on the precipitation response of AlMg3 and AlMg5 aluminium alloy, microstructure evolution and strength of the alloys. The microstructure variation was analysed using a scanning electron microscope and an optical microscope in order to characterise the microstructure in a heat treated condition. Tensile tests and hardness measurements were carried out to investigate the effect of heat treatment on the mechanical properties. [ABSTRACT FROM AUTHOR]

Equal channel angular pressing technique (ECAP) was used before and after solution heat treatment to obtain grain refinement and strengthening of commercial Al–Mg casting alloys. The experiments were performed to investigate the strengthening effect of the alloy after various post-ECAP ageing treatments. The alloys were severely deformed at room temperature following route B c and die channel angle of 120°. It was found that heat treatment before and after ECAP significantly affect and improves mechanical properties of aluminium alloys. It was also proven that the severe plastic deformation causes grain refinement which directly influence on properties of AlMg alloys. An increase of strength and ductility was achieved by appropriate selection of post-ECAP ageing. It is also proven that the good strengthening effect is also achieved at temperatures lower than those usually used for ageing. Based on the findings above, the tensile properties and hardness of Al–Mg alloys are discussed. [ABSTRACT FROM AUTHOR]

Composites and nanocomposites as commercially used engineering materials with continuous development, are important for rising market and industry needs. Significant role is played by polymers, whose consumption increases every year, thanks to low cost of production, economical processing and broad scope of material composition possibilities, including nanomaterials and basing on them nanocomposites. Nanocomposites, using power of nanotechnology, may improve physical, chemical and mechanical properties, comparing to composites. Investigation of structure and properties of such materials is necessary to obtain knowledge about phenomena at micro and nanoscale and gives opportunity to design and control structure, because the properties of any material depend on its matter. Polymer matrix nanocomposites are interesting and very promising class of polymer composites. Investigation of structure development due to different heat treatment and under different processing condition of injection molded specimens of polypropylene and montmorillonite composition has been performed. Dispersion of nanoreinforcement, in the shape of 2:1 layer silicates, was observed under transmission and scanning electron microscope. Application of advanced technology of multiplication of oriented layer mostly reinforcing and orienting micro and nanoparticles along polymeric specimen, allowed to obtain several layers and significantly reinforced material. Light microscope has been used for observation layered zone, visible just in polarization mode. [ABSTRACT FROM AUTHOR]

Abstract: This research project presents the investigation results of laser remelting and alloying especially the laser parameters and its influence on the structure and properties of the surface of the 32CrMoV12-28 and X38CrMoV5-3 hot work steels, using the high power diode laser (HPDL). As a result of the performed research structure changes were determined concerning the grain size and reinforcement ceramic particle distribution in the steel surface layer. The reason of this work was to determine the optimal laser treatment parameters, particularly the laser power applied to achieve good layer mechanical properties for protection of this hot work tool steel from losing their work stability and to make the tool surface more resistant to action in hard working conditions. For alloying the tantalum carbide TaC, niobium carbide NbC as well as titanium carbide TiC powders were used. For investigations of the alloyed samples hardness and microhardness measurements of the different remelting areas were performed. The remelted layers which were formed in the surface of investigated hot work steel were examined metallographically and analyzed using light and scanning electron microscope as well as the investigations concerning ear resistance of the produced surface layer were carried out [Copyright &y& Elsevier]

Abstract: Results are presented of the chemical composition, qualitative and quantitative examinations of the test pieces’ microzones and of the observations of transverse fractures surfaces of the modified casting magnesium alloys based on the EN-MCMgAl9Zn1 alloy. Presence of the following casting alloys main elements was confirmed in the analysed test pieces: magnesium, aluminium, manganese and zinc, constituting the structure of the α solid solution with the Mg17Al12 phases precipitations, as well as eutectics and phase AlMnFe, Mg2Si. Fractures of the investigated alloys were of a mixed nature. The investigation is carried out to testy the influence of the chemical composition and precipitation processes on the structure and mechanical properties of the magnesium cast alloys with different chemical composition in its as-cast alloys and after heat treatment. [Copyright &y& Elsevier]

Abstract: Magnesium and magnesium alloys are primarily used in aeronautical and automobile industry in large variety of structural characteristics because of their favorable combination of tensile strength (160–365MPa), elastic modulus (45GPa), and low density (1740kg/m3), which is two-thirds that of aluminum. Magnesium alloys have high strength-to-weight ratio (tensile strength/density), comparable to those of other structural metals. Application, structure and mechanical properties of selected magnesium alloys were investigated. [Copyright &y& Elsevier]