The factors necessary to obtain an optimal heat treatment that influence the hardness and resistivity of Al-6Si-0.5Mg casting alloys with Cu or/and Ni additions were investigated. The alloys were homogenised (24hr at 500C), solutionized (2hr at 540C) and artificially ageing at various times and temperatures. The alloys were aged isochronally for 60 minutes at temperatures up to 400C and isother...

The temperature dependence of the heat of hydration of natrolite was studied by isothermal adsorption calorimetry from 412 to 472 K. The heat capacity of hydration implied by these results is about 5 times greater than the calorimetric heat capacity of reaction, suggesting atypical behavior across this solid solution.

this article addresses the interplay between heat of hydration and physico-mechanical properties of calcium sulfate hemi-hydrate in the presence of retarding additives such as citric and malic acids and sodium citrate. the heat of hydration was measured using a semi-isothermal calorimeter. results proved that citric and malic acids had superior impact on hydration and mechanical properties. whi...

This study consists of the experimental and numerical analysis phase transformations 5Cr-0.5Mo.0.1C steel after heat treatment. The microstructure as-received comprised ferrite bainite, which is in agreement with microconstituents predicted by Calphad-calculated TTT diagram. Calphad-based precipitation calculations show that cooling stage normalizing treatment did not cause carbide formation. I...

The efficiency of the ideal stirling cycle assumes, that the cylinder volumes are isothermal and that the temperatures in the cylinder volumes are identical to the temperatures in the heat sink and the heat source. The efficiency is then identical to the efficiency of the Carnot cycle. However, in a real stirling machine the cylinder volumes are nearly adiabatic instead of isothermal, and the h...

the effects of isothermal aging at temperatures between 550-850 ?c for durations of 1-100 h on microstructure, tensile properties, and impact fracture behavior of 316l austenitic stainless steel weld metal have been investigated. for this purpose, various techniques including metallographic observations, measurement of ferrite content using ferritscope, and fractographic investigations have bee...