A mechanical seal promotes the connection between systems or mechanisms, preventing the escape of fluids to the exterior. Nonetheless, due to extreme working conditions, premature failure can occur. Diamond, due to its excellent properties, is heralded as an excellent choice to cover the surface of these devices and extend their lifetime. Therefore, the main objective of this work was to deposit diamond films over mechanical seals and test the coated seals on a water pump, under real working conditions. The coatings were created by hot filament chemical vapor deposition (HFCVD) and two consecutive layers of micro-and nanocrystalline diamond were deposited. One of the main difficulties is the attainment of a good adhesion between the diamond films and the mechanical seal material (WC-Co). Nucleation, deposition conditions, and pre-treatments were studied to enhance the coating. Superficial wear or delamination of the film was investigated using SEM and Raman characterization techniques, in order to draw conclusions about the feasibility of these coatings in the WC-Co mechanical seals with the purpose of increasing their performance and life time. The results obtained gave a good indication about the feasibility of this process and the deposition conditions used, with the mechanical seals showing no wear and no film delamination after a real work environment test.

The standard uniaxial tensile test is the widely accepted method to obtain relevant properties of mechanical characterization of sheet metal materials. However the range of strain obtained from tensile test is limited. The bulge test is an alternative to obtain ranges of deformation, higher than tensile test, thus permitting a better characterization for material behaviour. This paper presents a sensitivity analysis for some influencing variables used in bulge measurements, thus giving some guidelines for the evaluation of the stress-strain curve from experimental results using a developed experimental mechanical system. Additionally, using bulge test up to fracture shall give material information regarding damage, which in turn may be used to evaluate and calibrate damage models. A methodology is presented to be used for evaluation and calibration of Ito-Goya damage model of damage prediction.

Abstract. In this work an integrated model for all the process of glass forming of glass containers is presented. The model addresses press-and-blow and blow-and-blow procedures from the gob forming to the final product. Glass forming involves coupled thermal-mechanical physical phenomena, in which the material viscous flow is highly dependent on heat transfer which, in turn, is dependent changes of shape due to material flow. Numerical aspects associated with the model implementation and its validation with real formed products are discussed.

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