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Different Heat Treatments (different + heat_treatment)
Selected AbstractsMagnetic properties of screen-printed (Y0.5Sm0.5)Co5 magnet arraysPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 6 2007D. Bueno-Baques Abstract (Y0.5Sm0.5)Co5 magnet arrays of square ,dots of 300 ,m were prepared by screen printing. A well controlled paste like ink prepared with the (Y0.5Sm0.5)Co5 nanoparticles and a mixture of organic solvent and polymer was used to print different pattern arrays. (Y0.5Sm0.5)Co5 nanoparticles were obtained by mechanical milling starting from arc melted ingots and heat treated in Ar atmosphere. Two different heat treatment were considered, resulting in powders with different magnetic properties. The microstructure of the magnet arrays was studied by scanning electron microscopy (SEM). An isotropic homogeneous distribution of the nanoparticles inside the ,dots was observed. The final shape of the ,dots in the array was found to be highly dependent on the squeeze pressure and speed over the mesh. Magnetic properties were studied by pulsed field magnetometry and vibrating sample magnetometry at room temperature. The micro size arrays showed lower saturation magnetization and a slightly increase in the coercive field. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Roll-Bonded Titanium/Stainless-Steel Couples, Part 2: Mechanical Properties after Different Material-Treatment RoutesADVANCED ENGINEERING MATERIALS, Issue 1-2 2009S. Dziallach The accessible mechanical properties of a roll-bonded titanium/stainless-steel couple, consisting of grade-1 titanium and a low-carbon Cr-Ni-Mo-steel (1.4404), after different heat treatments are described. The mechanical properties, determined by tensile and stretch-forming tests, facilitate the optimum process widow for the heat-treatment parameters after roll bonding. The results of stretch-forming tests to determine the forming limits of the composite are shown. These tests also give important indications of the failure mechanism of the composite. Deep-drawing tests allow a first estimation of the deep-drawing functional area for a subsequent forming process to be made. [source] Detection of Sublethal Thermal Injury in Salmonella enterica Serotype Typhimurium and Listeria monocytogenes Using Fourier Transform Infrared (FT-IR) Spectroscopy (4000 to 600 cm,1)JOURNAL OF FOOD SCIENCE, Issue 2 2008H.M. Al-Qadiri ABSTRACT:, Fourier transform infrared (FT-IR) spectroscopy (4000 to 600 cm,1) was utilized to detect sublethally heat-injured microorganisms: Salmonella enterica serotype Typhimurium ATCC 14028, a Gram-negative bacterium, and Listeria monocytogenes ATCC 19113, a Gram-positive bacterium. A range of heat treatments (N= 2) at 60 °C were evaluated: 0D (control), 2D, 4D, 6D, and 8D using a D60 °C (S. enterica serotype Typhimurium ATCC 14028 = 0.30 min, L. monocytogenes ATCC 19113 = 0.43 min). The mechanism of cell injury appeared to be different for Gram-negative and Gram-positive microbes as observed from differences in the 2nd derivative transformations and loadings plot of bacterial spectra following heat treatment. The loadings for PC1 and PC2 confirmed that the amide I and amide II bands were the major contribution to spectral variation, with relatively small contributions from C-H deformations, the antisymmetric P==O stretching modes of the phosphodiester nucleic acid backbone, and the C-O-C stretching modes of polysaccharides. Using soft independent modeling of class analogy (SIMCA), the extent of injury could be predicted correctly at least 83% of the time. Partial least squares (PLS) calibration analysis was constructed using 5 latent variables for predicting the bacterial counts for survivors of the different heat treatments and yielded a high correlation coefficient (R= 0.97 [S. enterica serotype Typhimurium] and 0.98 [L. monocytogenes]) and a standard error of prediction (SEP= 0.51 [S. enterica serotype Typhimurium] and 0.39 log10 CFU/mL [L. monocytogenes]), indicating that the degree of heat injury could be predicted. [source] Effect of Equivalent Thermal Treatments on the Color and the Antioxidant Activity of Tomato PureeJOURNAL OF FOOD SCIENCE, Issue 9 2002M. Anese ABSTRACT: The influence of different heat treatments on color and antioxidant properties of tomato purees was investigated. The treatments were designed to produce the same total thermal effect against spoilage microorganisms. Although the development of nonenzymatic browning reactions occurred by increasing process temperature, no changes in redness were observed in the heated samples, due to the "masking" effect of lycopene. Also, the heat treatments had equivalent effect on the chain-breaking activity of the aqueous and lycopene tomato fractions. However the redox potential values increased as the heating temperature increased. All data together showed that the thermal resistance constant z values for color and chain-breaking activity were close to 10°C, but lower than 10°C for reducing properties. [source] Corrosion behaviour of tool steels in tannic acidsMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 3 2009H. Winkelmann Abstract It is well known that cutting knifes in the wood industry often suffer from corrosion. Investigations showed that the corrosiveness of different wood types is responsible for a major part of the damage, and that different woods have a different corrosive impact. It is revealed that tannin, a water-soluble acid, which can be found in all woods in different concentrations, is the most aggressive acid contained in the wood, and so it is responsible for the main part of the corrosive attack. In view of the above, the ability of different cold-work steels to resist corrosion caused by tannic acid has been investigated. Often corrosion is measured by the mass loss of the sample divided by the surface of the sample under certain conditions during a fixed period of time. One problem with this method is that there is also a weight gain caused by oxidation or by other side reactions at the samples surface. So in some cases the weight of the sample even increases during the testing time, which makes the quantification of the corrosion impossible with this method. Due to the reasons already mentioned, another method was used to quantify the test results. This method is based on inductive coupled plasma,optical emission spectral analyses (ICP-OES), where the released Fe is quantified. The results of the corrosion resistant tests get correlated to the microstructure and the elemental composition of the analysed cold-work steels. The present investigations improve the understanding of important material parameters to enhance the corrosion resistance against tannin. It is revealed that the higher the primary carbide concentration is the more Cr or other passivating elements are necessary in the matrix to show a good protection against corrosion by tannin. Three materials with different elemental compositions have been investigated, and for one of those materials the influence of different heat treatments was also analysed. The investigations could show that annealing parameters and freeze-cycle processing (FCP) have less impact on the corrosion resistance to tannin than elemental composition and austenitising temperature. [source] Modelling and parameter comparison of equivalent circuits on the basis of impedance measurements of stainless steelsMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 4 2006M. Slemnik Abstract In our former work [1] we have discussed the impedance of differently heat treated steels X20Cr13 in 0.1 M H2SO4, undergoing an active passive transition. Impedance spectra were interpreted in terms of a model by Armstrong [2, 3], describing the electrochemical reaction at interfaces with adsorbed intermediates. The present work was performed in order to study this phenomenon in more detail, with computer simulations of a new created and more convenient equivalent circuit in comparison with the former model. Computer simulations of equivalent circuits were also made in the region of passivity which was also continuation of our earlier work [4]. In this sense the entire study for these steels was completed by collating distinctive parameter values, demonstrating electrochemical characteristics of steel X20Cr13, undergoing different heat treatments in the active-passive and passive region. [source] | ||||||||||