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Showing 1 to 20 of 39 for “"transformation temperature"”.
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Development of low transformation temperature welding (LTTW) consumables, The
Includes bibliographical references (pages 149-156).
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Flux Growth of Single Crystal Lead-Titanate and Property Measurements
… Of particular concern is the disruptive phase transformation at approximately 500$\sp\circ$C, and the attainment of large equidimensional crystals free of defects. A flux method was developed for the growth of single crystals at reduced temperatures. High quality crack-free crystals were …
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Transformation induced plasticity in ceramics
Transformation induced plasticity was investigated in a model ceramic. The effect upon toughness of the martensitic transformation from the cubic (paraelectric) to the tetragonal ( ferroelectric) phase in BaTiO3 was determined. The K1C fracture toughness, as measured by the hardness indentation …
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On the Physics of Ice Nucleation and Growth in Nanoscale
… mainly by convective heat transfer. Water-ice transformation of few nm nanodroplets plays a critical role in nature including climate change, microphysics of clouds, survival mechanism of animals in cold environments, and a broad spectrum of technologies. In most of these scenarios, water-ice …
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The Effect of Milling Time on the Structure and the Properties of Mechanically Alloyed High Carbon Iron-Carbon Alloys
… was detected in all milled powders, and its transformation temperature decreased with milling time. In the literature, no explanation was found. In this work, this peak was found to be due to the formation of Fe_3 C phase. A DSC exothermic peak around 300°C was observed in powders milled for …
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Characterization and Catalytic Properties of Sulfated Zirconia
… the evolved gas species and to monitor the phase transformation temperature of the solid. Four samples [(1%) 5% Pt/S04 2-VZr02, 2% Fe/0.5% Mn (iron(III)nitrate, maganese(II) nitrate treated/iron(III) sulfate, maganese(II) sulfate treated)/S04 2-/Zr02] were studied by thermal analysis. Also, the …
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Discovering novel platinum structures
The Pt[8]Zr ordering transformation in Pt 11 at. % Zr alloys has been studied. The study included determination of the formation of the Pt[8]Zr phase and its order/disorder transformation temperature (Tc). Electron diffraction patterns and dark field images were obtained from transmission electron …
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Shape Memory Alloys for small scale actuation
… shape memory properties of interests, such as transformation temperature and fatigue, and suggests future work to improve Cu-based SMA wires..
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Effect of Nonequilibrium Defects Due to Phase Transformation on Diffusion in Beta Zirconium
The effect of the hcp(--->)bcc phase transformation on the anomalous diffusion characteristics of bcc zirconium has been investigated in this study. ('113)Sn and ('59)Fe tracers were used to typify the diffusing nature of self- and fast-diffusing atoms. A differential measurement of diffusion in …
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Modelling of Microstructure Development in Silicon-containing Bainitic Free-machining Steels
… The theories of all the major solid state phase transformations involved in steel are reviewed in chapter 2. The theory of the simultaneous transformation model is presented in chapter 3.uu A recalescence model dealing with the heat of reaction has been developed in chapter 5 for bar-shaped …
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Development of LTTW consumables for the enhancement of mechanical properties and residual stress management in thin steel welded joints
… is typically limited by the weldments. Low transformation temperature welding (LTTW) consumables are characterized by low martensite start temperature and large fraction of martensite forming in the weld. It can efficiently reduce the tensile residual stress because the volume expansion …
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"Examination of Several Potential ""Transformation Weakeners"" for Ceramic-Composite Interfaces"
… towards identifying several displacive phase transformations which could potentially be used in composites with alumina, YAG, and/or mullite. Phase transformations were examined in four materials: the rare earth pyroaluminates, e.g. $\rm Y\sb4Al\sb2O\sb9$; leucite, $\rm KAlSi\sb2O\sb6$; $\rm …
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Pathways to a Family of Low-Cost, High-Performance, Metal Matrix Composites Based on Aluminum Diboride in Aluminum
… Al(L) + AlB 2 → Al(L) + AlB12 peritectic transformation and the growth of AlB2 in aluminum. The equilibrium peritectic transformation temperature was redetermined and found to be 950 +/- 5°C. The kinetics of the peritectic transformation were measured and reported for the first time. …
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A rotary shape memory alloy actuator for CubeSat deployable structures
… to meet this need. A SMA can be annealed at high temperatures to remember a trained shape. Upon cool down, the SMA element transforms to the martensite phase and is easily deformed. When the element is heated above the transformation temperature it transforms to the stiff austenite phase and …
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Metallic MoS2 Nanosheets for Lithium-Sulfur Batteries
… °C in dry air—well above the conventional phase transformation temperature of ~100 °C. We establish that moisture is the primary degradation factor, enabling conventional fabrication methods in dry-room conditions rather than requiring costly fully inert environments. Second part of the thesis …
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Defect-induced magnetism and transport phenomena in epitaxial oxides
… All experiments, from varying deposition temperature, to oxygen pressure, to laser fluence or to the insertion of (doped) perovskite layers, point towards a structurally governed conduction mechanism, although the exact details are still unclear. Distinct transitions in the resistance …
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Nanoindentation Under Dynamic Conditions
… to investigate the mechanical effects of these transformations on foils of palladium. Study of palladium foils, which had been cycled through hydrogenation and dehydrogenation, allowed the extent of the transformed region to be determined. Unstable palladium foils, which had been hydrogenated …
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Preparation and characterization of doped lead zirconate titanate Pb(Zr<sub>x</sub>Ti<sub>1-x</sub>)O₃ films
… of various thickness and annealed at a range of temperatures and times. The effects of dopants were studied in terms of the Curie temperature, crystal distortion, transformation temperature, microstructure, optical properties, and electrical properties. In addition to the dopant effect, the …
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Synthesis And Characterization Of Transition Metal Arsenide Nanocrystals And The Metastability And Magneto-Structural Phase Transition Behavior Of Mnas Nanocrystals
… on (1) probing the magneto-structural phase transformation in nanoscale MnAs; (2) evaluation of the size-dependent phase stability of type-B MnAs (prepared by rapid injection); and (3) developing a general synthetic method for transition metal arsenide nanoparticles.</p> <p>Discrete MnAs …
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The impact toughness of iron manganese alloys.
… and is thought to be due to deformation induced transformation of gamma→epsilon during sample preparation. It was concluded that bulk austenite and epsilon concentrations are best obtained after 2 minutes electro--polishing. Additions of 0.1%Ti and 0.1%Al to 'pure' alloys, in order to getter …
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