Mekanik Alaşımla Süresince Al85Co7Y8 Alaşımının Faz Değişimi

Bu çalışmada nanoyapılı Al85Co7Y8 (at.%) alaşımı, mekanik alaşımlama (MA) tekniği kullanılarak elemental tozların katı hal reaksiyonuyla sentezlenmiştir. Toz alaşımlar, argon gazı altında sertleştirilmiş paslanmaz çelik hazne ve bilyeler kullanılarak yüksek-enerjili bilyeli değirmen içerisinde 300 saatlik öğütme işlemine tabi tutulmuştur. Öğütme işlemi süresince numunelerdeki yapısal ve morfolojik değişimler X-ışını difraksiyonu (XRD) ve taramalı elektron mikroskobu (SEM) ile termal kararlılıkları ise diferansiyel termal analiz (DTA) ile incelenmiştir. MA işlemi sonucunda aşırı doymuş fcc-Al katı çözelti fazı içeren alaşımlar üretilmiştir. Al85Co7Y8 alaşımının 300 saatlik öğütme işlemi sonrasındaki kristalit boyutu yaklaşık 16 nm olarak bulunmuştur.

Phase Evolution of Al85Co7Y8 Alloy during Mechanical Alloying

In this study, the nanostructured Al85Co7Y8 (at.%) alloy was synthesized by a solid state reaction from the constituent elemental powder mixture via mechanical alloying (MA). The powder mixture was ball milled for times up to 300 h in a planetary high energy mill using hardened steel media under argon atmosphere. Structural and morphological changes during the milling process were characterized by a combination of X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Thermal stability of the milled powders was investigated using differential thermal analysis (DTA). The results showed that supersaturated α-Al solid solution was formed in the whole content of the milled material. The mechanically alloyed Al85Co7Y8 powder for 300 h of milling indicated the formation of fine nanoparticles with a size of about 16 nm.

___

  • [1] Suryanarayana, C. (2004). Mechanical alloying and milling. Marcel Dekker, New York, USA. 466s.
  • [2] Inoue, A. (1998). Amorphous, nanoquasicrystalline and nanocrystalline alloys in Al-based systems. Prog. Mater. Sci., 43, 365-520.
  • [3] Viet, N.H., Oanh, N.T.H., Quynh, P.N.D., Lap, T.Q. ve Kim, J.S. (2015). Thermal stability of amorphous Al-Fe-Y prepared by mechanical alloying. Mater. Sci. Forum, 804, 271-274.
  • [4] Inoue, A. (2000). Stabilization of metallic supercooled liquid and bulk amorphous alloys, Acta Mater., 48, 279-306.
  • [5] Gogebakan, M. (2004). Thermal stability and mechanical properties of Al-based amorphous alloys. J. Mater. Proc Techn., 153-154, 829-832.
  • [6] Avar, B., Gogebakan, M., Tarakci, M., Gencer, Y. ve Kerli, S. (2013). Microstructural investigations of rapidly solidified Al-Co-Y alloys. Adv. Mater. Sci. Eng., Article ID 163537.
  • [7] Sun, Z., Xing, Q., Axinte, E., Ge, W., Leng, J. ve Wang, Y. (2015). Formation of highly thermal stable Al88Ni6Y6 amorphous composite by graphene addition design. Mater. Design, 81, 59-64.
  • [8] Wang, T., Sun, Z., Zhang, L. ve Wang, Y. (2016). Glass formation and thermal stability of mechanically alloyed Al75Ni10Ti10Zr5 amorphous composites with graphene addition. Mater. Sci. Forum, 849, 58-63.
  • [9] Maurya, R.S., Sahu, A. ve Laha, T. (2016). Effect of consolidation pressure on phase evolution during sintering of mechanically alloyed Al86Ni8Y6 amorphous powders via spark plasma sintering. Mater. Sci. Eng. A, 649, 48-56.
  • [10] Börner, I. ve Eckert, J. (2001). Phase formation and properties of mechanically alloyed amorphous Al85Y8Ni5Co2. Scripta Mater., 45, 237-244.
  • [11] Calin, M., Grahl, H., Adam, M., Eckert, J. ve Schultz, L. (2004). Synthesis and thermal stability of ball-milled and melt-quenched amorphous and nanostructured Al-Ni-Nd-Co alloys. J. Mater. Sci., 39, 5295-5298.
  • [12] Zhang, L.C., Calin, M., Branzei, M., Schultz, L. ve Eckert, J. (2007). Phase stability and consolidation of glassy/nanostructured Al85Ni9Nd4Co2 alloys. J. Mater. Res., 22, 1145-1155.
  • [13] Prashanth, K.G., Scudino, S., Murty, B.S. ve Eckert, J. (2009). Crystallization kinetics and consolidation of mechanically alloyed Al70Y16Ni10Co4 glassy powders. J. Alloys Comp., 477, 171-177.
  • [14] Viet, N.H., Oanh, N.T.H., Quynh, P.N.D., Lab, T.Q. ve Kim, J.S. (2015). Thermal stability of amorphous Al-Fe-Y prepared by mechanical alloying. Mater. Sci. Forum, 804, 271-274.
  • [15] Manna, I., Chattopadhyay, P.P., Banhart, F. ve Fecht, H.J. (2004). Development of amorphous and nanocrystalline Al65Cu35-xZrx alloys by mechanical alloying. Mater. Sci. Eng. A, 379, 360-365.
  • [16] Samanta, A., Manna, I. ve Chattopadhyay, P.P. (2007). Phase evolution in Al-Ni-(Ti, Nb, Zr) powder blends by mechanical alloying. Mater. Sci. Eng. A, 464, 306-314.
  • [17] Chen, H., Cheng, X., Zhang, J., Ouyang, Y., Du, Y., Zhong, X. ve Tao, X. (2008). The compositional range of amorphous phase formation and thermal stability of Al90-xFe5Ni5Cex. J. Alloys Comp., 460, 309-313.
  • [18] Mula, S., Ghosh, S. ve Pabi, S.K. (2009). On the formation of phases by mechanical alloying and their thermal stability in Al-Mn-Ce system. Powder Tech., 191, 176-181.
  • [19] Cullity, B.D., Stock, S.R. (2001). Elements of X-ray diffraction. 3 rd. Edition, Prentice Hall, New-Jersey, USA. 664s.
  • [20] Suryanarayana, C. (2001). Mechanical alloying and milling. Prog. Mater. Sci., 46: 1-184.
  • [21] Nayak, S.S., Wollgarten, M., Banhart, J., Pabi, S.K. ve Murty, B.S. (2010). Nanocomposites and an extremely hard nanocrystalline intermetallic of Al-Fe alloys prepared by mechanical alloying. Mater. Sci. Eng. A Mater. Sci. Eng. A, 527, 2370-2378.
  • [22] Nayak, S.S., Pabi, S.K. ve Murty, B.S. (2010). Al-(L12)Al3Ti nanocomposites prepared by mechanical alloying: synthesis and mechanical properties. J. Alloys Comp., 492, 128-133.