Browsing by Keyword "Nitrides"
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Item Mechanical properties of layers obtained by DC-pulsed plasma nitriding on a low-alloy steel (AISI 4140)(2009) Dutrey, Luciano; De Heras, Evangelina Las; Svoboda, Hernán G.; Corengia, Pablo A.; GENERALAn industrial DC-pulsed plasma nitriding (DCPPN) equipment was used to obtain samples of an AISI 4140 low-alloy steel with five different configurations: substrate, substrate + diffusion zone, diffusion zone, substrate + diffusion zone + compound layer, and diffusion zone + compound layer. The microstructures of the samples were investigated by scanning electron microscopy and X-ray diffraction. Microhardness and tensile tests were performed, and the fracture mechanisms for the different materials were finally analyzed and discussed. The DCPPN produced an increase in the elastic modulus as well as in the yield strengths, together with a pronounce ductility loss, associated to the brittle intergranular fracture surface due to the nitride precipitation in the grain boundaries.Item Microstructural, mechanical and tribological properties of CrA1YN coatings deposited by magnetron sputtering(2009) Brizuela, Marta; García-Luis, Alberto; Corengia, Pablo; González-Santamaría, Daniel; Muñoz, Roberto; González, Javier Jesús; INGENIERÍA DE SUPERFICIES; TECNOLOGÍAS DE HIDRÓGENO; GENERALCrAlYN coatings were synthesized by reactive magnetron sputtering. The aim of this research is to study the influence of the nitrogen flow at constant total gas flows on the chemical, structural and tribo-mechanical properties of the CrAlYN coatings. The nitrogen flow has an important effect on the deposition growth rate, the crystalline structure and the mechanical properties of the CrAlYN coatings. AU the coatings present a NaCl fee lattice structure but increase in the nitrogen flow changes the coating texture. Coatings morphology also changes from a columnar to an equiaxial structure. Coating hardness decreases with increase in the nitrogen flow. AU the coatings studied showed a similar tribological behaviour with a mean friction coefficient against steel between 0.47 and 0.53 without showing a clear correlation with the coatings' mechanical properties.