A superior SiC based thermal protection coating process for carbon composite, which can be especially effective in a hot oxidizing atmosphere, was established in this study. A multi-coating process based on a combination of Chemical Vapor Reaction (CVR) and Chemical Vapor Deposition (CVD) was developed. Various protective coating layers on carbon composite were tested in hot oxidizing surroundings and the test results verified that the thermal ablation rate could be dramatically reduced down to 3.8% when the protective multi-coating was applied. The thermal protection mechanism of the coating layers was also investigated.

Silicon (Si) is the second most abundant element present in the lithosphere, and it constitutes one of the major inorganic nutrient elements of many plants. Although Si is a nonessential nutrient element, its beneficial role in stimulating the growth and development of many plant species has been generally recognized. Silicon is known to effectively reduce disease severity in many plant pathosystems. The key mechanisms of Si-mediated increased plant disease resistance involve improving mechanical properties of cell walls, activating multiple signaling pathways leading to the expression of defense responsive genes and producing antimicrobial compounds. This article highlights the importance and applicability of Si fertilizers in integrated disease management for crops.

Bollworms comprise the most harmful and economically relevant species of lepidopteran. Helicoverpa gelotopoeon (D.) (Lepidoptera: Noctuidae) is native to America and affects many crops. Tobacco is an industrial crop in which methods of pest control rely mainly on the application of insecticides. To develop new eco-friendly strategies against insect pests it is very important to overcome the side effects of insecticides. The utilization of fungal entomopathogens as endophytes is a new perspective that may accomplish good results. The present study aimed to evaluate the ability of endophytic Beauveria bassiana (Bals.-Criv.) Vuill. to affect H. gelotopoeon life parameters and feeding behavior on tobacco plants. Beauveria bassiana LPSC 1215 as an endophyte did not reduce the amount of vegetal material consumed by H. gelotopoeon larvae but affected the life cycle period of the plague, particularly the larval and adult stages. Also, egg fertility was affected since adults laid eggs that were not able to hatch. The results of this investigation provide new information on endophytic entomopathogen potential to be incorporated in Integrated Pest Management (IPM) programs.

The paper presents the research results of horizontal continuous casting of ingots of aluminium alloy containing 2% wt. silicon (AlSi2).

Together with the casting velocity (velocity of ingot movement) we considered the influence of electromagnetic stirring in the area of the

continuous casting mould on refinement of the ingot’s primary structure and their selected mechanical properties, i.e. tensile strength, yield

strength, hardness and elongation. The effect of primary structure refinement and mechanical properties obtained by electromagnetic

stirring was compared with refinement obtained by using traditional inoculation, which consists in introducing additives, i.e. Ti, B and Sr,

to the metal bath. On the basis of the obtained results we confirmed that inoculation done by electromagnetic stirring in the range of the

continuous casting mould guarantees improved mechanical properties and also decreases the negative influence of casting velocity, thus

increasing the structure of AlSi2 continuous ingots.

In paper is presented idea of construction and influence of selected parts of stand of horizontal continuous casting on quality of pure Al and AlSi2

alloy ingots. The main parts of the made stand belong to induction furnace, which is also tundish, water cooled continuous casting mould, system

of recooling, system of continuous ingot drawing and cutting. Mainly was considered influence of electromagnetic stirrer, which was placed

in continuous casting mould on refinement of ingots structure. Effect of structure refinement obtained by influence of electromagnetic stirring was

compared with refinement obtained by use of traditional inoculation, which consists in introducing of additives i.e. Ti and B to metal bath. The

results of studies show possibility of effective refinement of Al and AlSi2 alloy primary structure, only with use of horizontal electromagnetic field

and without necessity of application of inoculants. This method of inoculation is important, because inoculants decrease the degree of purity

and electrical conductivity of pure aluminum and moreover are reason of point cracks formation during rolling of ingots.

This study manufactured a SiC coating layer using the vacuum kinetic spray process and investigated its microstructure and wear properties. SiC powder feedstock with a angular shape and average particle size of 37.4 μm was used to manufacture an SiC coating layer at room temperature in two different process conditions (with different degrees of vacuum). The thickness of the manufactured coating layers were approximately 82.4 μm and 129.4 μm, forming a very thick coating layers. The SiC coating layers consisted of α-SiC and β-SiC phases, which are identical to the feedstock. Cross-sectional observation confirmed that the SiC coating layer formed a dense structure. In order to investigate the wear properties, ball crater tests were performed. The wear test results confirmed that the SiC coating layer with the best wear resistance achieved approximately 4.16 times greater wear resistance compared to the Zr alloy. This study observed the wear surface of the vacuum kinetic sprayed SiC coating layer and identified its wear mechanism. In addition, the potential applications of the SiC coating layer manufactured using the new process were also discussed.

The aim of this paper is to present a new approach to the problem of silicon integrated spiral inductors modeling. First, an overview of models and modeling techniques is presented. Based on 3D simulations and published measurement results, a list of physical phenomena to be taken into account in the model is created and based on it, the spiral inductor modeling by frequency sampling method is presented. To verify the proposed method a test circuit, containing 6 spiral inductors was designed and integrated in a silicon technology. The parameters of the spiral inductors from the test circuit were next measured and compared with simulations results. The comparison for one of those six spiral inductors is presented in the article.

The paper discusses the application of the current-source concept in the gate drivers for silicon carbide transistors. There is a common expectation that all SiC devices will be switched very fast in order to reach very low values of switching energies. This may be achieved with the use of suitable gate drivers and one of possibilities is a solution with the current source. The basic idea is to store energy in magnetic field of a small inductor and then release it to generate the current peak of the gate current. The paper describes principles of the current-source driver as well as various aspects of practical implementation. Then, the switching performance of the driven SiC transistors is illustrated by double-pulse test results of the normally-ON and normally-OFF JFETs. Other issues such as problem of the drain-gate capacitance and power consumption are also discussed on the base of experimental results. All presented results show that the currentsource concept is an interesting option to fast and efficient driving of SiC transistors.

The paper stresses the issue of strong temperature influence on the gain of a Silicon Photomultiplier (SiPM). High sensitivity of the detector to light (single photons) requires stable parameters during measurement, including gain. The paper presents a method of compensating the change of gain caused by temperature variations, by adjusting a suitable voltage bias provided by a precise power module. The methodology of the research takes in account applications with a large number of SiPMs (20 thousand), explains the challenges and presents the results of the gain stabilization algorithm.

The article presents crystallization process of silicon molybdenum ductile cast iron (SiMo). The alloy with 5% silicon content and with

variable amounts of Mo in a range of 0-1% was chosen for the research. The carbon content in the analysed alloys did not exceed 3,1%.

The studies of crystallization process were based on thermal – derivative analysis (TDA). Chemical composition of all examined samples

was analysed with the use of LECO spectrometer. Additionally, the carbon and the sulphur content was determined basing on carbon and

sulphur LECO analyser. For metallographic examination, the scanning electron microscopy (SEM) with EDS analyser was used. Disclosed

phases have been also tested with the use of X-ray diffraction. The results allowed the description of crystallization processes of silicon

molybdenum ductile cast iron using thermal – derivative analysis (TDA). Conducted studies did not allow for the clear identification of all

complex phases containing molybdenum, occurring at the grain boundaries. Therefore, the further stages of the research could include the

use of a transmission electron microscope to specify the description of complex compounds present in the alloy.

Preliminary tests aimed at obtaining a cellular SiC/iron alloy composite with a spatial structure of mutually intersecting skeletons, using a

porous ceramic preform have been conducted. The possibility of obtaining such a composite joint using a SiC material with an oxynitride

bonding and grey cast iron with flake graphite has been confirmed. Porous ceramic preforms were made by pouring the gelling ceramic

suspension over a foamed polymer base which was next fired. The obtained samples of materials were subjected to macroscopic and

microscopic observations as well as investigations into the chemical composition in microareas. It was found that the minimum width of a

channel in the preform, which in the case of pressureless infiltration enables molten cast iron penetration, ranges from 0.10 to 0.17 mm. It

was also found that the ceramic material applied was characterized by good metal wettability. The ceramics/metal contact area always has

a transition zone (when the channel width is big enough), where mixing of the components of both composite elements takes place.

The article presents results of pitting corrosion studies of selected silicon cast irons. The range of studies included low, medium and high

silicon cast iron. The amount of alloying addition (Si) in examined cast irons was between 5 to 25 %. Experimental melts of silicon cast

irons [1-3] were conducted in Department of Foundry of Silesian University of Technology in Gliwice and pitting corrosion resistance

tests were performed in Faculty of Biomedical Engineering in Department of Biomaterials and Medical Devices Engineering of Silesian

University of Technology in Zabrze. In tests of corrosion resistance the potentiostat VoltaLab PGP201 was used. Results obtained in those

research complement the knowledge about the corrosion resistance of iron alloys with carbon containing Si alloying addition above 17 %

[4-6]. Obtained results were supplemented with metallographic examinations using scanning electron microscopy. The analysis of

chemical composition for cast irons using Leco spectrometer was done and the content of alloying element (silicon) was also determined

using the gravimetric method in the laboratory of the Institute of Welding in Gliwice. The compounds of microstructure were identify by

X-ray diffraction.

The formation of oxide film on the surface of aluminium melts, i.e. bifilms, are known to be detrimental when they are incorporated into

the cast part. These defects causes premature fractures under stress, or aid porosity formation. In this work, Al-12 Si alloy was used to cast

a step mould under two conditions: as-received and degassed. In addition, 10 ppi filters were used in the mould in order to prevent bifilm

intrusion into the cast part. Reduced pressure test samples were collected for bifilm index measurements. Samples were machined into

standard bars for tensile testing. It was found that there was a good agreement with the bifilm index and mechanical properties.

This article focuses on the study of the influence of remelting and subsequent natural and artificial ageing on the structure of recycled AlSi9Cu3 alloy with increased iron content. The assessed changes in eutectic silicon and iron-based intermetallic phases were carried out using optical and scanning electron microscopy. The degradation of the eutectic silicon morphology due to remelting occurred only at the highest numbers of remelting. The effect of remelting the investigated alloy, which is accompanied by a gradual increase in wt. % Fe, began to manifest significantly through a change in the length of the ferric phases after the fourth remelting. As expected, the artificial ageing process has proven to be more effective than natural ageing. It has led to a change in the eutectic silicon morphology and has been beneficial in reducing the lengths of adverse ferric phases. The use of alloys with higher numbers of remelting, or with greater “contamination”, for the manufacture of shape-challenging castings is possible when using a suitable method of eliminating the negative factors of the remelting process. The results of our investigation show a suitable method of the above elimination the application of heat treatment T5 – via artificial ageing.

439L stainless steel composites blended with fifteen micron SiC particles were prepared by uniaxial pressing of raw powders at 100 MPa and conventional sintering at 1350oC for 2 h. Based on the results of X-ray diffraction analysis, dissolution of SiC particles were apparent. The 5 vol% SiC specimen demonstrated maximal densification (91.5%) among prepared specimens ­(0-10 vol% SiC); the relative density was higher than the specimens in the literature (80-84%) prepared by a similar process but at a higher forming pressure (700 MPa). The stress-strain curve and yield strength were also maximal at the 5 vol% of SiC, indicating that densification is the most important parameter determining the mechanical property. The added SiC particles in this study did not serve as the reinforcement phase for the 439L steel matrix but as a liquid-phase-sintering agent for facilitating densification, which eventually improved the mechanical property of the sintered product.