Abstract: Solar control glass has applications for windows and glazed facades in order to modify indoor visual and thermal comfort in buildings. The article presents the results of evaluation study of optical properties of selected types of solar control glasses and foils. The spectral transmittance measurements were used as input data for daylight comparative studies, and the consideration of convenience of selected solar control glasses and foils for windows are summarised on the basis of analysis of optical properties.
Abstract: Components of navigating devices can be affected by acoustic emission and vibration. Therefore prototype samples and electronic components must be tested in such conditions. Heterostructures, which destructed under the action of external physical factors and kinetics of formations of porous defects in silicon substrates, were analyzed.
Abstract: The paper presents finite element analysis of spreading process of hollow steel tubes implemented within commercial software MES FORGE2-V3.0. To this purpose, rigid-plastic model of deformed material was assumed. The analysis was realised for hollow tube made from steel C45 with external diameter D0 = 50 mm and internal one d0 = 40 mm. Distributions of temperature, stress and deformation for different values of gradient radius of mandrel (1535) and different friction conditions on the area of metal-tool were determined. With the piercing press the billet is introduced into a vertical or horizontal die, subsequently to be pierced by mandrel. Afterwards pipe is elongated in Diescher’s mill. Hollow steel tubes undergo hot deformation spreading process in two-roll press by mandrel. Process stability depends on dimensions of the hollow tube and mandrel: tube external diameter, tube internal diameter, mandrel diameter and inclination angle of mandrel. Increase of external diameter of hollow tube occurs in the course of spreading process by mandrel. Process parameters depend on chemical composition and type of material. In this paper the contact problem in metal – tool interface is considered. Burnishing implies the sizing of a hollow tube by its plastic spreading.
Abstract: Modern materials on intermetallic matrix are in the scope of research of many scientific – research centers in Poland . Intermetallic systematic alloys containing aluminium have high resistance to oxidation, abrasive corrosion and fatigue as well as heat resistance. That is why they are applied in the production of machine parts used in hard service conditions (internal combustion turbine blades, exhaust valves, turbo-blower rotors) . Intermetallic coatings can be obtained by means of plasma spraying. Thermal spraying technology is widely used due to the possibility of increasing the service properties in surface layers (strength property, tribological, anti-corrosive and decorative property) as well as coating application on machine parts elements, on tools for plastic working (forging moulds busters, piston rods, gear wheels teeth, crank journals, valve seats, and combustion engine cylinders) [3, 4]. NiAl and Ni3Al coatings are characterized by high fatigue resistance, heat resistance and considerable corrosion resistance . Coatings obtained by thermal spraying have high surface roughness. Thus, subsequent plastic treatment is advisable for plasma-sprayed intermetallic coatings. Therefore it is vital to define to what extent the change of unit pressure will influence reduction of surface roughness of intermetallic coatings. For this purpose experimental upsetting research was carried out on C45 steel samples having NiAl and Ni3Al coatings for the following unit pressures p = 500 MPa, p = 800 MPa, p = 1100 MPa.
Abstract: In the aspect of growing popularity of hydroxyapatites and HA-based composites (with addition of ZrO2 phase) used in medicine, it seems to be crucial to determine accurate percentage content of ZrO2 phase addition in the mixture ensuring invariable or predictable changes in dimensions of implants or coatings after the process of sintering. In consideration of the aforementioned statement, combined mathematical and statistical analysis enabling prediction of such changes was carried out.
Abstract: Ceramic materials included in the group of advanced materials are increasingly used in different fields of science and technology as well as in everyday life. Hydroxyapatite ceramics (HAp, HA), based on calcium phosphates, i.e. chemical compounds being a constituent of natural bone, is found to be one of the best implantation materials for bone surgeries and dentistry. Due to poor mechanical properties of hydroxyapatite ceramics, the attempts are made to modify HA materials in order to extend the scope of current applications. It is also necessary to maintain high biocompatibility and bioactivity. Reported investigations encompassed comparison of functional properties of HA and HA+ZrO2 coatings (modified with 8%wt. Y2O3) as well as coatings remelted with laser beam. Microstructural and phase analyses of the coatings before and after remelting were carried out. In order to determine biocompatibility of the coatings after plasma spraying and remelting, corrosion resistance testing was also performed in Ringer’s solution.
Abstract: The research results for polynomial tensor interpolation of tribological wear of austenitic 316L steel are analyzed for the first time in this paper. A tribological study was carried out on the tester T-05, both for samples after the process of glow discharge nitriding and for samples of 316L steel in the initial state [1, 2]. The influence of the nitriding parameters on the weight loss of the samples during the abrasion test and the friction coefficient of the abrasion pair were determined. In this paper the actual results which were obtained so far during the research of tribological wear in an interpolative area were put together with the theoretically determined and experimentally verified real research results for tribological wear in the area beyond the scope of interpolation. It was determined that each of the selected nitriding parameters significantly affects abrasive wear resistance of 316L steel, at the same time, in the nitriding process, as time and temperature increase the resistance to wear abrasion becomes better. The mathematical model for planning of experiments with different glow discharge nitriding processes combined with polynomial interpolation of the obtained research results of many variable functions will enable to choose the nitriding process parameters to obtain the assumed and required property of useful nitrified elements. The developed computer program enables multidimensional interpolation of the research results and is a universal tool which can be used in any research field.
Abstract: In many cases of residual stress testing by Barkhausen method, the microstructure of the sample used for calibration procedure and tested material is fairly different though made form the same steel grade. These differences can be observed even in the same investigated product, for example, in steel shapes. Due to this fact, this paper presents the preliminary results of experimental investigations of the influence of microstructure state (modified by heat treatment) on Barkhausen noise parameters and, finally, on residual stress measurement by Barkhausen method.