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The article is an obituary that reports on the death of Francisco Cruz Gandarilla, one of the pioneers of materials science. Francisco Cruz was an outstanding Cuban physicist, graduating in 1974 from the University of Havana. He specialized in X-ray Diffraction, Crystallography, and Electron Microscopy, and conducted research on texture analysis in metallic alloys. He published over 60 articles in high-level journals and participated in scientific events in Cuba and abroad. Additionally, he was recognized for his tireless dedication and his contribution to the construction of the faculty's structure laboratory. Francisco Cruz passed away at the age of 72, leaving behind his wife, Lola, who accompanied him during his illness. [Extracted from the article]

Nowadays, Zinc Aluminum Alloys (ZA) are generally used for galvanization, in order to prevent the attack produced by corrosion. In this investigation, the microstructure of deposited layers of ZA on SAE 1020 steel is evaluated, as well as its behavior when submitted to tensile tests. For this purpose, several standardized test were carried out according to the norm COVENIN 299, after applying the covering layers of alloys; Zn-4%Al, Zn-%6Al and the Zn-10%Al by the method of hot immersion. After performing the tensile test, a metallographic examination was made, according to norm ASTM E-3. The measurement of the thickness of the layers and the counting of cracks was made by Optics Microscopy (OM). The microstructure analysis was made by Scanning Electronic Microscopy (SEM). The characterization of the micro-components was made with the application of EDX. It can be concluded that the samples with better mechanical properties, were those covered with the alloy of Zn - 6%Al. The observed microstructure displayed Zn-Al-Fe precipitates in a rich Zinc matrix; they increase in quantity and size with the percentage of aluminum in the alloy. [ABSTRACT FROM AUTHOR]

This work presents the determination of intrinsic values (metal alloy composition) of medals, using a laboratory developed portable X-Ray Fluorescence (XRF) spectrometer based in miniaturized low power X-ray tube (max. 50 kV 1 mA, Pd anode) and Si-PIN detector . The analyses were carried out without sampling or contact with surface of medals. The application of this non destructive analytical method in Numismatic is demonstrated and exemplified with the study of a collection of Cuban primary schools medals (1850-1960). The medals are characterized through the concentrations of metals and pigments. Anachronisms and metal alloy were identified in medals of year's 50s (XX). Questions about Cuban or North American provenance or attribution to specific Cuban jeweller's workshop of the non marked medals of the collection were answered through the analysis of bivariate plots of XRF characteristic line area of marker metals: Ni/Cu vs. Zn/Cu y Au/Cu vs. Zn/Cu. Significant differences between attributed medals of the Havana's jewelleries: Fuentes & Alvarez and Bustamante y Hnos. and the North American jewelleries: Art Co. and Green Duck Co., which allows to attribute the non marked medals granted by Cuban schools. The metal concentrations of 22 most important medals of this collection were calculated using the external standard method and certified standard reference materials. [ABSTRACT FROM AUTHOR]

A characterization of coating obtained from the cuban chromite and boric acid as sources of the saturating elements using optical microscopy, x-ray diffractometry and scanning electronic microscopy was carried out. The layers present phases of complex chromium carbides of the type (Cr, Fe) 23 C6, (Cr, Fe)7 C3. The contents of chromium and iron in the layers vary with the saturated mixtures composition. [ABSTRACT FROM AUTHOR]

Some alloys Fe-C have an excellent combination of toughness and strength, related to bainitic reaction products, being useful in manufacturing of machine components subjected to high stresses. However, in our medium the knowledge of this transformation is reduced; it makes difficult a competition of industrial sector in the global economy. In this work it has been made a summary of basic issues of bainitic reaction, further to the review of classic books of phase transformations and considering last advances that it has been realized in its study. In addition, it's compiled the issues more important of bainite as in steels as much as in ductile irons. It is discussed the reaction mechanisms, reaction kinetic, microstructure characteristics and mechanical properties. The goal is diffuse notions and techniques required to implantation of this phase transformation, promoting the bainitic products development. [ABSTRACT FROM AUTHOR]

In this work it has been carried out the anticorrosive study of Turbomax 15W/40 oil, being produced by Castrol Cuba S. A., in order to prove the lubricating oil in motors OM-366A, used by local buses MB in Santiago de Cuba. In order to determine the influence of temperature and acidity over the corrosion rate, it was applied a complete factorial design of type 32, with two independent variables (temperature and acidity) and a dependent variable (corrosion rate) for each alloy, determining the mathematical pattern which permits to evaluate the results obtained. [ABSTRACT FROM AUTHOR]