Marián Buršák

The Influence of Severe Plastic Deformation on Structure and Mechanical Properties the Aluminium Alloy EN AW 6082

The effect of severe plastic deformation by ECAP process on the microstructures and mechanical properties of the aluminium alloy EN AW 6082 produced by cold extrusion is investigated. In both states were evaluated the structural changes by light microscopy, the analysis particles in structures, by X-ray diffraction (XRD) in transmission mode by synchrotron radiation and mechanical properties. Severe plastic deformation leads to strengthening of investigated EN AW 6082 alloy but on the other hand the plasticity of ECAP-ed alloy decreases.

The Corrosion Properties of EN AW 7075 Aluminium Alloy in Power Industry

The study in this paper aimed on the corrosion properties of aluminium alloys used in the power industry. The corrosion characteristics were evaluated in the initial and state after severe plastic deformation of aluminium alloy AlZnMgCu. Due to the frequent interaction of fatigue failure accompanied corrosive failure (e.g. aircraft wings, turbine blades etc.) fatigue characteristics of selected alloy were evaluated. Standard corrosion characteristics such as corrosion potential, polarization resistance, corrosion rate and the corrosion products were evaluated for both states of an alloy in distilled water and SARS during exposition reaching 263 520 minutes.

Possibilities of Preparing Tools Working in Conditions of Abrasion Wear with the Modification of the Tool Surfaces by Nitridation

The proposed paper deals about the heat treatment of two types of chromium tool steels that are assigned to work in specific conditions of abrasion wear. The materials are heat treated to achieve high hardness for higher abrasion wear resistance. An additional increase of the materials abrasion wear resistance can be achieved by applying nitridation with diffusion annealing of the material surface. The paper deals about the influence of the material purity, his chemical composition on the process of diffusion, the quality of the nitrided layer of a vacuum smelted steel Bӧhler W400 VMR and a chromium steel X210Cr12.

Influence of the Strain Rate and Heat Treatment on the Mechanical Properties of Steel Sheets

The paper analyses the influence of the strain rate on the behaviour of unalloyed steels with Re 210 – 550 MPa in the deformation process. It presents and analyses the results of the influence of the strain rate ranging from 10-3 to 2.5.102 s-1 on the yield point, the tensile strength, the elongation and the reduction of area. It analyses the non-homogeneity of development of plastic deformation from both the macroscopic and microscopic points of view, as well as the influence of the strain rate on the development of plastic deformation. Since the intensity of the influence of the strain rate on the properties of materials depends on their internal structure, the tested steels are divided into three groups based on their yield point and yield point to tensile strength ratio.

Influence of Severe Plastic Deformation on the Properties of a Selected Aluminium Alloy

This article deals about structural, mechanical and fatigue properties of an aluminium alloy EN AW 6061 (AlMg1SiCu) reinforced with SiC particles, in the initial state and in the state after intensive plastic deformation acquired by the process ECAP (Equal Channel Angular Pressing). In both states microstructures were evaluated with metallographic procedures, mechanical properties (yield strength, ultimate tensile strength, elongation) and fatigue curve at cyclic load in torsion. The main goal of this article was to study the influence of the intensive plastic deformation on an aluminium alloy reinforced with SiC particles prepared by powder metallurgy technique.

Increase of Tool Steel Durability in Abrasion Wear Conditions

The article proposes possible increase of durability of tool steel X210Cr12 as regards working conditions under consideration of abrasive wear. From such steel tools are made for pressing wooden briquettes and saw dust waste. In practical environment a condition is held that if a material should work in abrasive wear conditions, it should have high hardness and should contain carbides in the structure. The proposed paper deals with the heat and chemical-heat treatment (nitriding) of tool steel which is working in hard abrasive wear conditions. From the obtained results it is not easy to conclude a definitive conclusion or to set the boundaries between the factors that are responsible for wear resistance. It is shown that the chemical-heat treatment can in the last step of the heat treatment lead to an increase or even to a decrease in the abrasive wear resistance of the material. The aim of the paper is to set a proper heat treatment of materials used for pressing in abrasion wear conditions.