Advanced Materials Research Vol. 1036

Abstract: In order to determine the effect on the properties of precipitation processes conducted S700MC steel heat treatment consisting of annealed steel test temperatures: 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200 and 1300 °C. Sample obtained after the heat treatment process has been tested by Charpy V toughness, metallographic testing and measurement of Vickers hardness. In order to determine the strength and plastic properties of simulated heat affected zone S700MC steel material tensile test was carried out according to PN-EN 10002-1 for round samples. The study showed that the stability of bainitic structure is maintained to a temperature of 600 °C. In the temperature range 700 to 1000 °C, the test steel with ferritic-pearlitic structure with a small grain growth. The heat treatment above 1000 °C increases the amount of ferrite in the structure, and a strong growth of grain size. Tested steel retains its strength and hardness properties of the heat treatment does not exceed 600 °C. When this temperature is exceeded the tensile strength and hardness are significantly lower in comparison to the base material. Temperatures warm temperatures corresponding to the normalization cause loss of property obtained in the initial thermomechanical rolling process. It is impossible to return to the property upon cooling to ambient temperature, thus constantly this group should not be hot forming.

Abstract: The primary objective of the present research was to provide a fundamental understanding of the processing science necessary to fabricate the Aluminum Nitride (AIN) reinforced Aluminum-Magnesium (AIMg) composites via Reactive Gas (N2) Injection in the AIMg alloy melt. Aluminum nitride (AlN) matrix composites were prepared by a novel approach. It was possible to produce a considerable amount of AIN particles in the AI alloy matrix at a reaction temperature as low as 900 °C utilizing the in-situ nitration reaction process developed in the present study. The volume fraction of AIN increases almost linearly with increasing the magnesium (Mg) content in the alloy and the reaction time. The shapes of AIN particles were found to have different forms, whose sizes were in the range from submicron to a few microns. From the present study, it is concluded that the new innovative in-situ nitridation process developed in the present study can be successfully applied for processing of high strength AIMg/AIN composites. For particles and composite structure characterization some methods were used, including: scanning microscopy, quantitative analysis of selected composite regions and XRD analyses. Composite structure and reinforcement distribution was compared with use of quantitative analysis. Morphology and diffraction pattern of aluminum nitride particles was shown. Typical structure of studied composites with microanalysis results was indicated. Aluminum nitride dispersion change was represented.

Abstract: The investigations are focused on high-manganese austenitic steels used for reinforcing elements of car body. The purpose of this work was to examine the influence of thermo-mechanical treatment workout using Gleeble simulator and LPS module for semi-industrial hot-rolling on the structure and transformations occurring during cold deformations. Thermo-mechanical treatment consists of four passovers with a planned strain rate of about 20%. There were three variants of cooling after thermo-mechanical treatment: cooling in water, natural air-cooling and cooling in water after isothermal holding in the temperature of last deformation 850°C for 30 s. Structural observation were carried on LEICA MEF4A light microscope, analysis of the chemical composition were made with XPert PRO diffractometer, and the results were analyzed with OriginLab. It was found that the high-manganese austenitic X11MnSiAl7-1-3 steel after thermo-mechanical treatment on Gleeble simulator is characterized by dynamically recrystallized structure. In intervals time between each compression metadynamic and static recrystallization take place. After hot-rolling these steels has austenitic structure with dynamically recovered grains and with small metadynamically and statically recrystallized grains that are located on a border of elongated grains of austenite.

Abstract: Silver alloys, due to its specific properties are widely used in different branches of industry, with approximately 95% of the world silver production is used in the photographic industry and for jeweller production. Moreover Poland is a significant producer of silver in the world, and takes the 6th place on the list of the world's silver producers with the KGHM Polish Copper Company production on the first place among global companies providing silver on the market, with an annual production at 1281 tones. Because of this impotent role of silver, this work presents microstructure and mechanical properties investigations results of the long aged Ag-Cu alloys used mainly for mint monetary production. The purpose of this work was to determine the microstructural changes after 32 and 40 year of natural ageing time, with appliance of transmission electron microscopy as well as light microscopy. A very important issue - one of the investigations directions is also the possibility of study of spinodal decomposition process, which occurred in this alloy. After the long-time ageing of the material, there are detected morphological different areas of the Ag-α and Cu-β phase. As an implication for appliance in real conditions - as coin metal, or in electronic and chemical industry branches, there is the possibility of application of long term ageing for mechanical properties improvement by natural ageing method. Some other investigations should be performed in the future, but the knowledge found in this research shows an interesting investigation direction, where a low cost but long term treatment operations can be applied.

Abstract: Dumpers are the main components of the suspension system with vertical oscillations role in the absorption of the automobile. The combination of suspension coil with dumper is forming the main body of the suspension system. Shock absorber pipe is mainly used for production of motorcycles, cars (sedan) car shock absorber, is the size of the relatively high precision seamless pipe products, its manufacturing costs and lower selling prices relatively seamless, with excellent cost performance, got the car and motorcycle manufacturing industry recognition, are gradually replacing the use of seamless pipes in the area. The cold work process of pipes drawing consists of reducing the cross-section of a pipe by pulling the pipe through series of conical dies. The metal pipe drawing technology has been widely used to manufacture fine pipes. The influence of the degree of cold drawing on the mechanical properties of the carbon steel material were studied using the tensile test and hardness test experiments in order to replicate the service condition of the pipes used for automotive dumpers. Microstructure analysis were perfomed using optical analysis on a LEICA 5000DMI microscope up to 1000X magnitude and SEM images with a dual beam QUANTA 200 3D FEI SEM scanning electron microscope. The purpose of the work is to observe the main effects of the degree of reduction at different gradations by analysing the microstructure and mechanical proprieties behavior. The study used the stress-strain relationship of the tensile test experiment to study the effect of the degree of cold-drawing deformation on the yield strength and tensile strength properties of the dumpers used in automotive industry. The toughness of the low carbon steel used for the dumper manufacture reduces as the degree of drawing deformation increases. The ductility of the material also reduces with increasing degree of rawing deformation. The yield strength of the material was observed to reduce with increasing degree of cold-drawing, an indication of reduction in the ductility and the tensile strength of the material reduced with increasing degree of cold-drawn deformation. After high degrees of cold deformation by drawing, the hardness proprieties are increasing highlighted by cold-straining.

Abstract: It is crucial to know the distribution coefficients of chemical elements in melts. This is essential for obtaining a given composition and properties of epitaxial layers grown from the liquid phase, for determining the regimes of high purification of materials obtained by zone melting, for producing the desired gradient of distribution of alloying elements throughout the layers of construction materials treated by chemical-thermal methods, etc. This paper presents the results of computing the distribution coefficient of arsenic during the growth of layers of phosphide-arsenide of gallium from the liquid phase (molten gallium), saturated with phosphorus. We also obtain the dependencies between the distribution coefficient of arsenic, the temperature and the concentration of arsenic inside the gallium melt during the growth of epitaxial layers. As well a practical application of the results with a given gradient of concentration for the gallium arsenide layer is demonstrated.

Abstract: The present paper deals with the morphological alteration of fracture surfaces determined by hydrogen in the case of hydrogen based steels, through electrochemical methods as compared with similar samples of surfaces electrochemically uncharged or with welding deposits created by means of cellulose coated electrodes. Cellulose electrodes allow larger hydrogen quantities to be introduced into the metal deposited during the welding process. Hence, specific fractographic aspects are highlighted in view of interpreting prospective alterations caused by hydrogen based steels (13CrMo4.5 and S235 JR).

Abstract: The material conception of manufacture nanocomposite coatings with high dispersion phases are presented. The structure surface was obtained by modified technology HVOF aand PMR with micro-jet cooling. The macro and microstructure of composition coatings after the high temperature corrosion test are presented. The oxidation resistance of coatings contain multilayer structure with high dispersion ceramic particles are obtained. The presented coatings use to basic protection to wear and corrosion condition or modified surface of multilayer coatings in the energy boiler.

Abstract: This paper presents the results of experimental investigations and theoretical analysis of secondary physical phenomena that occur at interaction of electrical discharges in impulse (EDI) plasma radiation with color optical filter glasses. It was established that infrared filters (of type IKS) emit a violet secondary radiation, and dark filter (of type TS) emits a green secondary radiation. Detected phenomena can be explained by secondary radiation emission due to multi-photonic excitation of SiO₂ molecules and direct-inverse translating from one energy level to another. One of the resonance oscillatory levels (of the absorption bands) for molecules of SiO₂ is 780 cm^-1. Thus, for infrared filters the number of absorbed infrared photons is 33, and for dark glasses is 24. In this case, the wave length of secondary radiation is 388.5 nm (violet color) and 534.2 nm (green color) respectfully. This phenomenon can be applied in construction of equipment functioning based on monochromatic light radiation.

Abstract: Characterization of microstructure of silicide coatings obtained during diffusion process of pack cementation type was showed in this article. The basic materials were pure Mo sheet and TZM molybdenum alloys as well. The coatings were deposited in out of pack process with three different times of exposure. The temperature of deposition process was constant. In first step the phases compositions of coatings was described by XRD analysis. In each cases the MoSi₂ phase was obtained on top surface of the coatings. The morphology of the coatings was very similar as well. All types of coatings were characterized by network of cracks on top surface of the coatings. There was no influence of depositions time on phases constituent and coatings topography. LM and SEM analysis revealed that internal coatings morphology was very similar in all cases. Basic differences was related to the thickness of coatings. All coatings were good quality without deep cracks. Microstructure was a columnar-like type without pores and voids.