جستجوی مقالات مرتبط با کلیدواژه « حلالیت » در نشریات گروه « مواد و متالورژی »

In this research, with evaluation of the solubility of cyclotetramethylene tetranitramine (HMX) explosive in different concentrations of water- methyl ethyl ketone (MEK) solvent, at a temperature range of 40-70 °C, the solubility and some thermodynamic parameters such as enthalpy of dissolution and mixing were calculated. Thereafter, in order to increase the capacity of the crystallization process, the effect of digestion of HMX in evaporative crystallization procedure on the morphology and polymorph conversion of crude HMX was investigated using electron microscopy, X-ray diffraction (XRD) and Raman spectroscopy. Then, two quantitative methods based on the XRD and Raman spectroscopy were developed for the determination of -HMX in  -type samples. The results showed that with the mentioned methods, -polymorph can be determined in the linear dynamic range of 0.32-5.25 wt. % in  -HMX. Also, the crystallization studies in MEK using digestion and evaporative crystallization showed complete conversion of crude HMX polymorphs to  -type, along with significant increasing in the crystallization capacity.

Cu-Cr alloys with high electrical and thermal conductivity, high strength and good resistance to fatigue and corrosion, as well as good ductility have many applications in industry. These alloys are capable of being age-hardened. As Cr- content in solution before aging increases, their strength increases since more fine particles can be produced in the matrix during ageing stage of hardening. Therefore intensive works have been done to increase Cr solubility in Cu especially by rapid solidification of molten copper containing chromium. In the present work attempts have been done to introduce a method for production of Cu-Cr alloy with acceptable Cr-content with reasonable cost. Results show that maximum solubility of Cr in Cu matrix about 1.12 wt.% can be achieved.