Structural characterization of AA 2024-MoSi₂ nanocomposite powders produced by mechanical milling

Abstract

Nano-sized MoSi₂ powder was produced successfully from commercially available MoSi₂ by a mechanical milling process carried out for 100 h, and mechanical alloying was employed to synthesize AA 2024-MoSi₂ nanocomposites. The effects of MoSi2 reinforcement and mechanical milling on the structure, morphology, and iron contamination of the produced materials were investigated using X-ray diffraction, scanning electron microscopy, and atomic absorption spectrometry. It is revealed that the morphology of the aluminum alloy changes continuously during milling from spherical to plate-like, irregular, and finally equiaxed. The presence of MoSi₂ reinforcement accelerates the milling process and results in a smaller average particle size. The Williamson-Hall method determined that the crystallite size of the aluminum alloy in the composite powder is smaller than that of the unreinforced alloy at the same milling time and this size reaches 45 nm after 16 h milling time. The Fe contamination content is higher for the nanocomposite in comparison with the unreinforced alloy because of the wearing role of MoSi₂ hard particles.

Keywords

nanocomposites / aluminum alloys / mechanical milling / microstructure

References

[1] Han DS, Jones H, Atkinson HV. The wettability of silicon carbide by liquid aluminum: the effect of free silicon in the carbide and of magnesium, silicon and copper additions to the aluminum. J. Mater. Sci., 1993, 28, 2654.

[2] Zebarjad SM, Sajjadi SA. Dependency of physical and mechanical properties of mechanical alloyed Al-Al₂O₃ composite on milling time. Mater. Des., 2007, 28, 2113.

[3] Abdoli H, Salahi E, Farnoush H, Pourazrang K. Evolutions during synthesis of Al-AlN-nanostructured composite powder by mechanical alloying. J. Alloys Compd., 2008, 461, 166.

[4] Lai MO, Lu L, Laing W. Formation of magnesium nanocomposite via mechanical milling. Compos. Struct., 2004, 66, 301.

[5] Kang YC, Chan SL. Tensile properties of nanometric Al₂O₃ particulate-reinforced aluminum matrix composites. Mater. Chem. Phys., 2004, 85, 438.

[6] Lu L, Lai MO, Liang W. Magnesium nanocomposite via mechanochemical milling. Compos. Sci. Technol., 2004, 64, 2009.

[7] Fogagnolo JB, Robert MH, Torralba JM. Mechanically alloyed AlN particle-reinforced Al-6061 matrix composites: Powder processing, consolidation and mechanical strength and hardness of the as-extruded materials. Mater. Sci. Eng. A, 2006, 426, 85.

[8] Amigo V, Ortiz JL, Salvador MD. Microstructure and mechanical behavior of 6061Al reinforced with silicon nitride particles, processed by powder metallurgy. Scripta Mater., 2000, 42, 383.

[9] Sameezadeh M, Emamy M, Farhangi H. Effects of particulate reinforcement and heat treatment on the hardness and wear properties of AA 2024-MoSi₂ nanocomposites. Mater. Des., 2011, 32, 2157.

[10] Fogagnolo JB, Velasco F, Robert MH, Torralba JM. Effect of mechanical alloying on the morphology, microstructure and properties of aluminium matrix composite powders. Mater. Sci. Eng. A, 2003, 342, 131.

[11] Song M, He YH, Fang SF. Yield stress of SiC reinforced aluminum alloy composites. J. Mater. Sci., 2010, 45, 4097.

[12] Asgharzadeh H, Simchi A, Kim HS. Hot deformation of ultrafine-grained Al6063/Al₂O₃ nanocomposites. J. Mater. Sci., 2011, 46, 4994.

[13] Diaz C, González-Carrasco JL, Caruana G, Lieblich M. Ni₃Al intermetallic particles as wear-resistant reinforcement for Al-base composites processed by powder metallurgy. Metall. Mater. Trans. A, 1996, 27, 3259.

[14] Torres B, Lieblich M, Ibáñez J, García-Escorial A. Mechanical properties of some PM aluminide and silicide reinforced 2124 aluminium matrix composites. Scripta Mater., 2002, 47, 45.

[15] Walker JC, Ross IM, Rainforth WM, Lieblich M. TEM characterisation of near surface deformation resulting from lubricated sliding wear of aluminium alloy and composites. Wear, 2007, 263, 707.

[16] Corrochano J, Lieblich M, Ibáñez J. On the role of matrix grain size and particulate reinforcement on the hardness of powder metallurgy Al-Mg-Si/MoSi₂ composites. Compos. Sci. Technol., 2009, 69, 1818.

[17] Corrochano J, Walker JC, Lieblich M, Ibanez J, Rainforth WM. Dry sliding wear behaviour of powder metallurgy Al-Mg-Si alloy-MoSi₂ composites and the relationship with the microstructure. Wear, 2011, 270, 658.

[18] Rocha CJ, Neto RM L, Goncalves VS, Carvalho LL, Filho FA. An investigation of the use of stearic acid as a process control agent in high energy ball milling of Nb-Al and Ni-Al powder mixtures. Mater. Sci. Forum, 2003, 416–418, 144.

[19] Williamson GK, Hall WH. X-ray line broadening from filed aluminium and wolfram. Acta Metall., 1953, 1, 22.

[20] Mortensen MW, Sorensen PG, Björkdahl O, Jensen MR, Gundersen HJG, Bjørnholm T. Preparation and characterization of Boron carbide nanoparticles for use as a novel agent in T cell-guided boron neutron capture therapy. Appl. Radiat. Isotopes, 2006, 64, 315.

[21] Khakbiz M, Akhlaghi F. Synthesis and structural characterization of Al-B₄C nano-composite powders by mechanical alloying. J. Alloys Compd., 2009, 479, 334.

[22] Walker JC, Rainforth WM, Jones H. Lubricated sliding wear behaviour of aluminium alloy composites. Wear, 2005, 259, 577.

[23] Torres B, Lieblich M. Room and high temperature tensile behaviour of a P/M 2124/MoSi₂ composite at different heat treatment conditions. J. Mater. Sci., 2006, 41, 3493.

[24] Suryanarayana C. Mechanical alloying and milling. Prog. Mater. Sci., 2001, 46, 1.

[25] Hesabi ZR, Simchi A, Reihani SMS. Structural evolution during mechanical milling of nanometric and micrometric Al₂O₃ reinforced Al matrix composites. Mater. Sci. Eng. A, 2006, 428, 159.

[26] Maurice DR, Courtney TH. The physics of mechanical alloying: A first report. Metall. Mater. Trans. A, 1990, 21, 289.

[27] Lu L, Lai MO. Mechanical Alloying, 1998 165.

[28] Nasiri-Tabrizi B, Honarmandi P, Ebrahimi-Kahrizsangi R, Honarmandi P. Synthesis of nanosize single-crystal hydroxyapatite via mechanochemical method. Mater. Lett., 2009, 63, 543.

[29] Ortiz AL, Shaw L. X-ray diffraction analysis of a severely plastically deformed aluminum alloy. Acta Mater., 2004, 52, 2185.

[30] Chung KH, He JH, Shin DH, Schoenung JM. Mechanisms of microstructure evolution during cryomilling in the presence of hard particles. Mater. Sci. Eng. A, 2003, 356, 23.

[31] Parvin N, Assadifard R, Safarzadeh P, Sheibani S, Marashi P. Preparation and mechanical properties of SiC-reinforced Al6061 composite by mechanical alloying. Mater. Sci. Eng. A, 2008, 492, 134.

[32] Corrochano J, Lieblich M, Ibáñez J. The effect of ball milling on the microstructure of powder metallurgy aluminium matrix composites reinforced with MoSi₂ intermetallic particles. Compos. Part A, 2011, 42, 1093.