Metallurgical Study of Mechanical Milling Mechanism

Chapter 12

Metallurgical Study of Mechanical Milling Mechanism in Eutectic Nanopowders: The Role of Heterogeneities H. Rojas-Chávez, M.L. Mondragón-Sánchez, J.A. Andraca-Adame, and D. Jaramillo-Vigueras

Abstract A study of the addition of Pb–Sn nanoparticles, as heterogeneities, during the high-energy milling (HEM) process to achieve eutectic nucleation was carried out using chemical arguments, as well as X-ray powder diffraction and microscopy techniques. In addition to a change of energy source input, growth of eutectic alloys with the addition of Pb–Sn nano-heterogeneities promotes a more refined microstructure. The conventional melting/solidification method produced coarser microstructure than that of the high-energy milling process. To determine the mechanism responsible, eutectic nucleation in high-purity Pb–Sn mixtures, with and without the addition of Pb–Sn nano-heterogeneities, was studied. It was found that the addition of nano-heterogeneities exerts a positive effect on the nucleation process, while nucleation was not detected in the unmodified powder mixture. It was concluded that mixtures with the addition of nano-heterogeneities contain a large number of potent supersaturated nuclei that are susceptible to promote eutectic nucleation. Keywords High-energy milling • Eutectic • Heterogeneities • Nuclei • Nanopowders

H. Rojas-Chávez () Instituto Tecnológico de Tláhuac II, Tecnológico Nacional de México, Camino Real 625, Col. Jardines del Llano, San Juan Ixtayopan, Del. Tláhuac, CDMX. 13508, Mexico e-mail: [email protected] M.L. Mondragón-Sánchez Instituto Tecnológico de Morelia, Tecnológico Nacional de México, Av. Tecnológico 1500, Col. Lomas de Santiaguito, Morelia, Mich. 58120, Mexico J.A. Andraca-Adame Centro de Nanociencias y Micro y Nanotecnologías, Instituto Politécnico Nacional, Av. Luis Enrique Erro s/n, U.P.A.L.M. CDMX. 07738, Mexico D. Jaramillo-Vigueras Centro de Investigación e Innovación Tecnológica, Instituto Politécnico Nacional, Cerrada de CECATI s/n, Del. Azcapotzalco, CDMX. 02250, Mexico © Springer International Publishing Switzerland 2017 R. Pérez Campos et al. (eds.), Characterization of Metals and Alloys, DOI 10.1007/978-3-319-31694-9_12

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