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Cobalt-based γ–γ′ superalloys are novel heat-resistant materials suitable for high-temperature applications, such as components of the turbine engine. These alloys exhibit favorable strength and corrosion resistance at high temperatures owing to the γ–γ′ microstructure, analogous to that of Ni-based superalloys. The aim of this paper is to evaluate the oxidation behavior of basic Co-9Al-9W (at%) and new tungsten-free Co-10Al-5Mo-2Nb (at%) alloys at elevated temperatures. The investigation is concerned with thermogravimetric studies in the temperature range of 40–1200 °C. The oxidized surfaces after high temperature oxidation have been characterized using optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction analysis (XRD).

The article presents results of research relating to the impact of laser treatment done to the surface of plasma sprayed coatings NiCrAlY. Analysis consisted microstructure and oxidation resistance of coatings subjected to two different laser melting surfaces. The test were performed at a temperature 1000°C the samples were removed from the furnace after 25, 300, 500, 750 and 1000 hours. The investigations range included analysis of top surface of coatings by XRD characterization oxides formed types and microscopic investigations of coatings morphology

A2B2O7 oxides with pyrochlore or defected fluorite structure are among the most promising candidates for insulation layer material in thermal barrier coatings. The present paper presents the procedure of synthesis of holmium zirconate Ho2Zr2O7 and praseodymium zirconate Pr2Zr2O7 via Polymerized-Complex Method (PCM). Thermal analysis of precursor revealed that after calcination at relatively low temperature (700°C) fine-crystalline, single-phase material is obtained. Thermal diffusivity was measured in temperature range 25-200°C, Ho2Zr2O7 exhibits lower thermal diffusivity than Pr2Zr2O7. Additionally, PrHoZr2O7 was synthesized. The powder in as-calcined condition is single-phase, but during the sintering decomposition of solid solution took place and Ho-rich phase precipitated. This material exhibited the best insulating properties among the tested ones.

The paper presents the study on synthesis and thermal diffusivity of europium zirconate. Both materials were synthesized using two methods: conventional solid-state reaction (SSR) and polymerized-complex method (PCM). Thermal analysis of constituent oxides, their mixture and synthesized organic precursor was conducted. Structural characterization included analysis of morphology, chemical composition and phase composition, both for powders and sinters. Thermal diffusivity was measured in the temperature range from 25 to 700 °C. The materials obtained via chemical synthesis exhibited much better structural homogeneity. Eu 2 Zr 2 O 7 has ca. 23% lower thermal diffusivity than Eu 2 Hf 2 O 7 , regardless of synthesis method. There was also noticeable difference in measured thermal diffusivity depending on synthesis method which could be possibly attributed to the presence of non-stoichiometric phases.

A detailed characterization of the primary microstructure of laser-cladded NiCrAlY coatings deposited on two different substrate materials is presented in this article. Amdry 962 powder was used to deposit coatings by LENS (Laser Engineered Net Shaping) on Inconel 625 Ni-based superalloy and 316L stainless steel. An overall characterization of coatings was performed from a qualitative point of view with particular attention paid to cracks and pores. A description of microstructural aspects of the internal morphology of coatings, such as the microstructure, chemical, and phase composition were also investigated. The distribution of alloying elements, such as Fe, Mo, Nb, and Y, was investigated in cladded coatings on two different substrates. It was revealed that the cladded coatings contained cracks and gas voids typical for laser-cladding processes. The dendritic microstructure was the result of rapid solidification due to differences in the chemical composition of dendritic and interdendritic areas, which was related mainly to the yttrium concentration. Additionally, epitaxial growth during the initial stages of solidification was determined to be related to the diffusion of substrate alloying elements into the dilution zone. The strong influence of substrate materials, especially iron, in the final microstructure of coatings was analyzed. The oxidation of yttrium and the formation of Y-Al-O oxides were also analyzed.

Characterization of top-surface of NiCrAlY coating deposited by plasma spraying process on Inconel 625 Ni based superalloys was analyzed in two different completely conditions. First of them was as sprayed state of NiCrAlY coating and the second one was condition after grinding process. The basic aim of this treatment was related to obtain totally different conditions of coatings surface especially from roughness point of view. Those two types of top surface morphology was a base to comparison of oxidation resistant during static oxidation test at temperature of 1000°C and 1100°C. The temperature of static oxidation test was 1000°C and 1100°C. The specimens were moved out from furnace after 25, 300, 500, 750 and 1000 hours of exposition in laboratory air. The range of investigations after each interval included top surface characterization of specimens by SEM, XRD and EDS method. Those investigations showed that different types of top surface conditions had a fundamental influence on oxides layer morphology. Especially in the case of phase`s constituent of oxides zone. More detailed investigations were made on the cross sections of two types of investigated specimens. Analysis of oxides layer morphology showed in this case basic differences in thickness of oxides zone which was much higher in the case of as sprayed NiCrAlY coating.

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.

Of the very large number of cellular automata rules in existence, a relatively small number of rules may be considered interesting. Some of the features that make such rules interesting permit patterns to expand, contract, separate into multiple sub-patterns, or combine with other patterns. Such rules generally include still-lifes, oscillators, spaceships, spaceship guns, and puffer trains. Such structures can often be used to construct more complicated computational circuitry, and rules that contain them can often be shown to be computationally universal. Conway’s Game of Life is one rule that has been well-studied for several decades, and has been shown to be very fruitful in this regard.

Life, like many other cellular automata, contains many interesting objects, such as still lifes, oscillators, spaceships, spaceship guns, puffer trains, breeders, and the like. While many of these, like blocks, blinkers, and gliders, occur naturally with great frequency, there are many others that occur infrequently, and countless others that have never yet been observed in any natural context. This chapter deals with methods for synthesizing such complex objects from simple building blocks, such as gliders or other easy-to-synthesize objects. Once an object can be shown to be built in this manner, the object may be used as a building block in larger relocatable structures, such as Turing machines or universal constructors. In addition, the existence of a natural synthesis of an object from a bounded number of gliders implies that the object will form naturally in a sufficiently large, sufficiently sparse field [2]. Inasmuch as this chapter deals mainly with practical aspects of object synthesis, rather than theoretical ones, it may resemble a talk on chemical engineering, rather than abstract mathematics. All figures shown here, unless otherwise specified, show “before” and “after” images of collision sequences; the “before” sequences are shown on the left with dark cells, and the “after” sequences to the right of them in lighter cells. In some cases, unwanted debris is also generated and must be removed later; this debris is shown in the lightest color. There are several basic ways in which objects can be synthesized. The most common objects occur in great abundance in nature, so there are many random collisions of a small number of gliders that will produce them. There have been many random broth experiments conducted in Life, in which fields initialized to random initial configurations have been run until they became periodic, and then the resulting ash analyzed. The results of two such series of experiments, performed by Achim Flammenkamp [1] and Heinrich Koenig [3], are available on the Web. If the objects are sorted in order of decreasing frequency of natural occurrence, the list is also in order of increasing synthesis cost in gliders (with a few rare objects out of place).