Showing papers by "Ghulam Ishaq Khan Institute of Engineering Sciences and Technology published in 2000"
TL;DR: In this paper, the high-temperature, isothermal-oxidation behavior of a superalloy was studied in the as-rolled and deformed conditions using optical, scanning electron microscopy (SEM), fine-probe EDS microanalysis, and X-ray diffraction techniques.
Abstract: The high-temperature, isothermal-oxidation behavior of a superalloy was studied in the as-rolled and deformed conditions. The microstructural changes occurring during the oxidation of samples were examined using optical, scanning electron microscopy (SEM), fine-probe EDS microanalysis, and X-ray diffraction techniques. The topography of the oxide layers formed in the as-rolled and cold-deformed specimens exposed at various temperatures and time intervals is also examined. The kinetics and microstructural results are presented for the comparative study of the structural changes occurring during high-temperature oxidation. It was found that a Cr2O3 external layer was adherent and uniform on the rolled specimens in comparison to the scattered and preferential oxide developed on the deformed specimens. The latter can be attributed to the concurrent dynamic changes occurring in the deformed substructure that subsequently lead to breaking and spallation of the oxide.
31 citations
TL;DR: In this article, the effect of mix proportions has also been considered to ascertain the durability under the simulated conditions of adverse exposure during the hydration period, which ultimately determine the durable service life of a concrete structure.
7 citations
TL;DR: In this paper, the soaking temperatures were found to have a pronounced effect on the types of carbides formed, and it was also shown that a high volume fraction of fine secondary carbides (M23C6) results in inducing maximum hardness.
Abstract: Stainless steels containing 26Cr, 2Mo, and 1.6C are shown to contain primary and/or secondary carbides when subjected to various heat treatment routines. The soaking temperatures were found to have a pronounced effect on the types of carbides formed. It is also shown that a high volume fraction of fine secondary carbides (M23C6) results in inducing maximum hardness. Based on the results, optimal heat treatment cycles are proposed.
1 citations
TL;DR: In this article, the high-frequency behavior of superconducting NdBa2Cu3O6+x (NBCO) has been investigated by the standing-wave technique in the microwave region.
Abstract: The high-frequency behavior of superconducting NdBa2Cu3O6+x (NBCO) has been investigated by the standing-wave technique in the microwave region. The joule loss of the bulk NBCO sample, as determined from the voltage standing wave ratio (VSWR), falls markedly at Tc. In the low temperature region, i.e. for T