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Study of constrained sintering of powers used to cracks reparation

 

Estudio del sinterizado restringido de polvos utilizado para reparación de fisuras

 

L. Olmos¹*, A.M. Estrada-Murillo², J. Lemus-Ruiz², R. Huirache-Acuña³, H.J. Vergara-Hernández⁴, P Garnica-González⁴, and J.M. Salgado⁵

 

¹ Coordinación de la Investigación Científica. * Corresponding author. E-mail: luisra24@gmail.com.

² Instituto de Investigaciones Metalúrgicas.

³ Facultad de Ingeniería Química, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, México.

⁴ Posgrado de Ciencias en Metalurgia, Instituto Tecnológico de Morelia, México.

⁵ Centro de Ingeniería y desarrollo Industrial. Santiago de Querétaro, Querétaro, México.

 

Received May 28, 2013.
Accepted July 31, 2014.

 

Abstract

Sintering is a thermal treatment normally used to produce parts from different types of powders, and it is a phenomenon that has been studied since the 1950's. Mechanisms and diffusion paths for several materials have already been established. However, the use of sintering; powders to repair fissures on solid materials has rarely been studied. The aim of this work is to study the solid state sintering of copper powders filling artificial grooves in a bar of solid copper. Sintering was carried out in an electrical furnace under H₂ and Ar (10-90 respectively) atmosphere at two different temperatures, 1000 and 1050°C. The powder used to fill the grooves was a spherical atomized copper powder with a wide particle size distribution, 0-63/μm. Sintering of particles wat evaluated at the edge of the solid bar and at the center of the groove by scanning electron microscopy (SEM). It was observed that particles sintered well on the wall's surface at the site of the artificial groove. Greater densification reached by the smaller particles and higher sintering temperatures creates defects inside the groove. Those defects are the consequence of the constraints of sintering, and the necks developed during the thermal cycle could be broken by the higher stresses generated during densification.

Keywords: constrained sintering, copper, solid state sintering, defects evolution, cracks healing.

 

Resumen

El sinterizado libre es un tratamiento térmico usado para fabricar partes sótidas a partir de diferentes tipos de polvos. Este fenómeno se ha estudiado desde los años 50 y los mecanismos de difusión para diversos materiales son conocidos. Sin embargo, el sinterizado restringido ha recibido poca atención, a pesar de las aplicaciones que puede tener como la reparación de fisuras en materiales que no pueden ser soldados. El objetivo de este trabajo es estudiar el sinterizado restringido de polvos de cobre depositados al interior de una ranura creada artificialmente en barras sólidas de cobre. Se evaluó el efecto del tamaño de partícula y de la temperatura de sinterizado sobre la evolución microestructural. El sinterizado se llevó a cabo en un horno eléctrico a dos temperaturas, 1000 y 1500°C, bajo una atmósfera reductora de una mezcla de H₂ y Ar (10-90 respectivamente). Los polvos usados son esféricos y con dos distribuciones de tamaño de partícula, 0-40 y 40-63 /μm. La evolución del sinterizado fue evaluada al borde de la barra sólida y al centro de la ranura mediante microscopia electrónica de barrido. Los resultados muestran que el método es capaz de reparar fisuras y que los contactos entre partículas y las paredes se desarrollan de manera satisfactoria. Sin embargo, se encontró que altas densificaciones generan esfuerzos suficientemente fuertes para romper los contactos creados entre partícula-pared y también entre partícula-partícula, generando defectos como grietas o delaminaciones al borde de la pared. Se encontró que el uso de partículas de menor tamaño es más perjudicial para la unión entre partículas y pared.

Palabras clave: sinterizado restringido, cobre, sinterizado en estado sólido, evolución de defectos, reparación de fisuras.

 

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References

Anselmi-Tamburini U, Garay JE, Munir ZA. (2006). Fast low-temperature consolidation of bulk nanometric ceramic materials. Scripta Materialia 54, 823-828.         [ Links ]

Ch'ng HN, Pan J. (2007). Sintering of particles of different sizes. Acta Materialia 55 813-824.         [ Links ]

Coble R.L. (1958). Initial sintering of alumina and hematite. Journal of American Ceramic Society 41, 55-62.         [ Links ]

Exner H. (1979). Principles of single phase sintering. Reviews on Powder Metallurgy and Physical Ceramics 1, 7-251.         [ Links ]

Exner HE, Petzow G. (2006). A critical assessment of porosity coarsening during solid state sintering. Advances in Science and Technology 45, 539-548.         [ Links ]

Frenkel J. (1945) Viscous flow of crystalline bodies under the action of surface tension, Journal of Physics (Moscow).

German R.M. (1978). Surface area reduction kinetics during intermediate stage sintering. Journal of American Ceramic Society 61, 272-274.         [ Links ]

Henrich B, Wonisch A, Kraft T, Moseler M, Riedel H. (2007). Simulations of the influence of rearrangement during sintering. Acta Materialia 55, 753-762.         [ Links ]

Hsueh C.H. (1985).Sintering of a Ceramic Film on a Rigid Substrate. Scripta Metallurgica 19, 1213-1217.         [ Links ]

Khalil A.K., Abdulhakim A.A. (2012). Effect of high-frequency induction heat sintering conditions on the microstructure and mechanical properties of nanostructured magnesium/hydroxyapatite nanocomposites. Materials and Design 36, 58-68.         [ Links ]

Kingery WD, Berg M. (1955). Study of the initial stages of sintering solids by viscous flow, evaporation-condensation and self-diffusion. Journal of Applied Physics 26, 1205-1212.         [ Links ]

Kuczynski GC. (1949). Self-diffusion in sintering of metallic particles. Transactions ofthe American Institute of Mining and Metallurgical Engineers 185, 169-178.         [ Links ]

Lame O, Bellet D, Di Michiel M, Bouvard D. (2004). Bulk observation of metal powder sintering by X-ray synchrotron microtomography. Acta Materialia 52, 977-984.         [ Links ]

Martin CL, Bordia RK. (2009). The effect of a substrate on the sintering of constrained sintering. Acta Materialia 57, 549-558.         [ Links ]

Martin CL, Camacho-Montes H, Olmos L, Bouvard D, Bordia RK. (2009). Evolution of defects during sintering-discrete element simulations. Journal ofAmerican Ceramic Society 92, 1435-1441.         [ Links ]

Martin CL, Schneider LCR, Olmos L, Bouvard D. (2006). Discrete element modeling of metallic powder sintering. Scripta Materialia 55, 425-428.         [ Links ]

Mori K, Matsubara H, Noguchi N. (2004). Micro-macro simulation of sintering process by coupling Monte Carlo and finite element methods. International Journal ofMechanical Sciences 46, 841-854.         [ Links ]

Mori K, Ohashi M, Osakada K. (1998). Simulation of microscopic shrinkage behavior in sintering of powder compact. International Journal of Mechanical Sciences 40, 989-999.         [ Links ]

Olmos L, Martin CL, Bouvard D, Bellet D, Di Michiel M. (2009). Investigation of the sintering of heterogeneous powder systems by synchrotron microtomography and discrete element simulation. Journal of American Ceramic Society 92, 1492-1499.         [ Links ]

Olmos L, Martin CL, Bouvard D. (2009). Sintering of mixtures of powders: experiments and modeling. Powder Technology 190, 134-140.         [ Links ]

Olmos L, Takahashi T, Bouvard D, Martin CL, Salvo L, Bellet D, Di Michiel M. (2009) Analysing the sintering of heterogeneous powder structures by in situ microtomography. Philosophical Magazine 89, 2949-2965.         [ Links ]

Pan J, Le H, Kucherenko S, Yeomans JA. (1998). A model for the sintering of spherical particles of different sizes by solid state diffusion. Acta Materialia 46, 4671-4690.         [ Links ]

Panigrahi BB, Godkhindi MM, Das K, Mukunda PG, Ramakrishnan P. (2005). Sintering kinetics of micrometric titanium powder. Materials Science and Engineering A A396, 255-262.         [ Links ]

Parhami F, McMeeking RM. (1998). A network model for initial stage sintering. Mechanics of Materials 27, 111-124.         [ Links ]

Rasp T, Jamin C, Wonisch A, Kraft T, Guillon O. (2012). Shape Distortion and Delamination During Constrained Sintering of Ceramic Stripes: Discrete Element Simulations and Experiments. Journal of American Ceramic Society 95, 586-592.         [ Links ]

Scherer GW, Garino T. (1985). Viscous Sintering on a Rigid Substrate. Journal of American Ceramic Society 68, 216-220.         [ Links ]

Showaiter N, Youseffi M. (2008). Compaction, sintering and mechanical properties of elemental 6061 Al powder with and without sintering aids. Materials and Design 29, 752-762.         [ Links ]

Subrata K.G. Partha S. (2011). Crack and wear behavior of SiC particulate reinforced aluminium based metal matrix composite fabricated by direct metal laser sintering process. Materials and Design 32, 139-145.         [ Links ]

Tikare V, Braginsky M, Bouvard D, Vagnon A. (2006). An Experimental Validation of a 3D Kinetic, Monte Carlo Model for Microstructural Evolution during Sintering. Advances in Science and Technology 45, 522-529.         [ Links ]

Upadhyaya A, German RM. (1998). Densification and dilatation of sintered W-Cu alloys. International Journal of Powder Metallurgy 34, 43-55.         [ Links ]

Vagnon A, Riviere JP, Missiaen JM, Bellet D, Di Michiel M, Josserond C, Bouvard D. (2008). 3D statistical analysis of a copper powder sintering observed in situ by synchrotron microtomography. Acta Materialia 56, 1084-1096.         [ Links ]

Wei Z, Yong T, Bin L, Rong S, Lelun J, Hui KS, Hui KN, Haimin Y. (2012). Compressive properties of porous metal fiber sintered sheet produced by solid-state sintering process. Materials and Design 36, 414-418.         [ Links ]