High-entropy alloys al-co-cr-fe-mn-ni-si-v in as-cast and splat-quenched states

V. F. Bashev, O. I. Kushnerov

Abstract


This work is dedicated to establish the effects of the composition and the melt cooling rate on microhardness, phase composition and parameters of the fine structure of high-entropy alloys (HEA) of Al-Co-Cr-Fe-Mn-Ni-Si-V system in the ascast  and rapid quenched  state. Metodology. As-cast  alloy  samples  were  obtained  using  a  copper  mold  (cooling  rate  ~  10 2 K/s). Quenching from a liquid state was  carried  out  by  a  known  technique  of  splat-quenching  (SQ). Cooling rate estimated by foil thickness was ~ 10 6K/s. The X-ray diffraction analysis was carried out with use of the DRON-2.0 diffractometer.  Microhardness was measured on the PMT-3 microhardnessmeter. Selection of components of the studied HEAs was carried out on the basis of the criteria  adopted  in  the  literature  for  the  HEA  composition  based  on  calculation  of  the  entropy  and  enthalpy  of  mixing, valence electron concentrations as well as the difference between the atomic radii of the components. Findings. It was found that the as-cast alloys show a multiphase BCC+B2 structure, while the SQ alloys - fully disordered BCC crystal structure only. The value of lattice parameters of the investigated alloys suggests that the solid solutions are form on the base of Cr lattice, in view of its higher melting temperature.  All  of  the  as-cast  alloys  display  a  typical  cast  dendritic  structure  with  various  configurations  and volumes  of  the interdendritic  space.  The  positive  influence  of  microstrains  level  and  dislocation  density  on  the  microhardness  values  of  splatquenched  Al-Co-Cr-Fe-Mn-Ni-Si-V  alloys  has  been  established.  Improved  mechanical  characteristics  are  ensured  by  the  strong distortion of the crystal lattice due to the differences in atomic radii of the elements. It was found that the splat-quenching HEAs of Al-Co-Cr-Fe-Mn-Ni-Si-V system are characterized  by higher  values of  microhardness than as-cast alloys. Originality. At  present work were first obtained and studied HEAs of Al-Co-Cr-Fe-Mn-Ni-Si-V system in the as-cast and splat-quenched state. Practical value. The HEAs possess  many  attractive  properties,  such  as  high  hardness,  outstanding  wear  resistance,  irradiation  resistance, excellent  high-temperature  strength,  good  thermal  stability  and  corrosion  resistance. The  study  of  thin  films  obtained  by splatquenching  from  the  liquid  state  is  also  of  great  practical  interest,  since  one  of  the  promising  applications  of  HEAs  are  thin  film coatings.


Keywords


high-entropy alloy; splat-quenching; phase composition; structure; microhardnes.

Full Text:

PDF

References


Bashev V.F. and Kushnerov O.I. Structure and properties of high-entropy CoCrCuFeNiSnx alloys // The Physics of Metals and Metallography. 2014, vol. 115, no. 7, pp. 692–696.

Dong Y., Lu Y., Jiang L., Wang T. and Li T. Effects of electro-negativity on the stability of topologically close-packed phase in high entropy alloys // Intermetallics. 2014, vol. 52, pp. 105–109.

Dong Y., Zhou K., Lu Y., Gao X., Wang T. and Li T. Effect of vanadium addition on the microstructure and properties of AlCoCrFeNi high entropy alloy // Materials and Design. 2014, vol. 57, pp. 67–72.

Guo S., Liu C.T. Phase stability in high entropy alloys: Formation of solid-solution phase or amorphous phase // Progress in Natural Science: Materials International. 2011, vol. 21, no. 6, pp. 433–446.

Guo S., Ng C., Lu J. and Liu C.T. Effect of valence electron concentration on stability of fcc or bcc phase in high entropy alloys // Journal of Applied Physics. 2011, vol. 109, no. 10, pp. 1-5.

He J.Y., Wang H., Huang H.L., Xu X.D., Chen M.W., Wu Y., Liu X.J., Nieh T.G., An K. and Lu Z.P. A precipitation-hardened high-entropy alloy with outstanding tensile properties // Acta Materialia. 2016, vol. 102, pp. 187–196.

Körmann F., Ma D., Belyea D.D., Lucas M.S., Miller C.W., Grabowski B. and Sluiter M.H.F. “Treasure maps” for magnetic high-entropy-alloys from theory and experiment // Applied Physics Letters. 2015, vol.107, no. 14, p. 142404.

Lu Z.P., Wang H., Chen M.W., Baker I., Yeh J.W., Liu C.T. and Nieh T.G. An assessment on the future development of high-entropy alloys: Summary from a recent workshop // Intermetallics. 2015, vol. 66, pp. 67–76.

Miracle D., Miller J., Senkov O., Woodward C., Uchic M. and Tiley J. Exploration and Development of High Entropy Alloys for Structural Applications // Entropy. 2014, vol. 16, no.1, pp. 494–525.

Murty B.S., Yeh J.-W. and Ranganathan S. High-Entropy Alloys. Oxford: Butterworth-Heinemann, 2014, 219 p.

Singh A.K., Kumar N., Dwivedi A. and Subramaniam A. A geometrical parameter for the formation of disordered solid solutions in multi-component alloys // Intermetallics. 2014, vol. 53, pp. 112–119.

Shafeie S., Guo S., Hu Q., Fahlquist H., Erhart P. and Palmqvist A. High-entropy alloys as high-temperature thermoelectric materials // Journal of Applied Physics. 2015, vol. 118, no. 18, p. 184905.

Stepanov N.D., Shaysultanov D.G., Salishchev G. A. and Senkov O.N. Mechanical Behavior and Microstructure Evolution during Superplastic Deformation of the Fine-Grained AlCoCrCuFeNi High Entropy Alloy // Materials Science Forum. 2016, vol. 838-839, pp. 302–307.

Stepanov N.D., Shaysultanov D.G., Salishchev G.A. and Tikhonovsky M.A. Structure and mechanical properties of a light-weight AlNbTiV high entropy alloy // Materials Letters. 2015, vol. 142, pp. 153–155.

Takeuchi A. and Inoue A. Classification of bulk metallic glasses by atomic size difference, heat of mixing and period of constituent elements and its application to characterization of the main alloying element // Materials Transactions. 2005, vol. 46, no. 12, pp. 2817–2829.

Tsai M.-H. and Yeh J.-W. High-Entropy Alloys: A Critical Review // Materials Research Letters. 2014, vol 2, no. 3, pp. 107–123.

Yeh J.-W. Physical Metallurgy of High-Entropy Alloys // JOM. 2015, vol. 67, no. 10, pp. 2254–2261.

Yu P.F., Zhang L.J., Cheng H., Zhang H., Ma M.Z., Li Y.C., Li G., Liaw P.K. and Liu R.P. The high-entropy alloys with high hardness and soft magnetic property prepared by mechanical alloying and high-pressure sintering // Intermetallics. 2016, vol. 70, pp. 82–87.

Zaddach A.J., Niu C., Oni A.A., Fan M., LeBeau J.M., Irving D.L. and Koch C.C. Structure and magnetic properties of a multi-principal element Ni–Fe–Cr–Co–Zn–Mn alloy // Intermetallics. 2016, vol. 68. P 107–112.

Zhang Y., Yang X. and Liaw P.K. Alloy Design and Properties Optimization of High-Entropy Alloys // JOM. 2012, vol. 64, no. 7. pp. 830–838.

Zhang Y., Zhou Y.J., Lin J.P., Chen G.L. and Liaw P.K. Solid-Solution Phase Formation Rules for Multicomponent Alloys // Advanced Engineering Materials. 2008, vol. 10, no. 6, pp. 534–538.

Zhang Y., Zuo T.T., Tang Z., Gao M.C., Dahmen K.A., Liaw P.K. and Lu Z.P. Microstructures and properties of high-entropy alloys // Progress in Materials Science. 2014, vol. 61, pp. 1–93.


GOST Style Citations




Refbacks

  • There are currently no refbacks.