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72XV International Symposium on Self-Propagating High-Temperature Synthesis
MECHANICAL ALLOYING WITH PARTIAL AMORPHIZATION OF Fe-Cr-Co-Ni-Mn MULTICOMPONENT POWDER MIXTURE AND ITS SPARK PLASMA SINTERING FOR COMPACT HIGH-ENTROPY MATERIAL PRODUCTION
N. A. Kochetov*", A. S. Rogachev", A. S. Shchukin", S. G. Vadchenko", and I. D. Kovalev"
aMerzhanov Institute of Structural Macrokinetics and Materials Science, Russian Academy of Sciences, Chernogolovka, Moscow, 142432 Russia *e-mail: [email protected]
DOI: 10.24411/9999-0014A-2019-10065
This paper presents the results of studying the mechanical alloying (MA) effect on the surface morphology, microstructure, and atomic-crystal structure of multicomponent Fe-Cr-Co-Ni-Mn powder mixture particles. The following materials were used as initial components: radioengineering carbonyl iron powder (R-10 with an average particle size d = 3.5 p,m), nickel powder (NPE-1, d = 150 p,m), cobalt powder (PK-1u, d < 71 p,m), chromium powder (PH-1M, d < 125 p,m), and manganese powder (MR0, d < 400 p,m) were used. MA of the prepared mixture was carried out in the AGO-2 water-cooled mechanical activator using 9-mm steel balls with an acceleration of 90 g in air [1-3]. Alloying time varied between 5 and 90 min. The ratio of ball mass to the mass of the mixture was 20 : 1. XRD patterns of the initial and alloyed mixtures and the sample obtained by sintering were made using a DRON 3M diffractometer in FeXa radiation in the range of angles 20 = 30°^100°. The microstructure of mixtures and compact sample section after sintering was studied by scanning electron microscopy. It is found that no peaks of the initial components are present in the XRD pattern of the mixture after 90 min of mechanical activation, but there are peaks corresponding to the y-Fe-based solid solution phase having a face-centered crystal lattice with an amorphous phase content increased by 20% (Fig. 1).
30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 26, deg.
Fig. 1. XRD patterns of the initial mixture (1), and mixtures after MA: (2) for 5 min, (3) for 10 min, (4) for 15 min, (5) for 60 min, (6) for 90 min.
ISHS 2019 Moscow, Russia
A compact single-phase material was obtained by spark plasma sintering at 800°C for 10 min from the mixture after 90-min alloying. Figures 2 and 3 show the XRD pattern and overall view of compact sample, respectively.
Material density was 7.49 kg/cm3, specific electrical resistivity was 0.94^0.96 10-6 Omm, microhardness was 306^328 kg/mm2, and the phase was distributed uniformly throughout the volume (Fig. 4).
5000 -
4000 -
angle, deg
Fig. 2. XRD pattern of the compact material Fig. 3. Overall view of compact material
sample obtained by SPS from the mixture after sample obtained by SPS from the
90 min alloying. mixture after 90 min alloying.
Fig. 4. Microstructure of compact sample section after etching in the HCl + HNO3 mixture.
This work was supported by Russian Foundation for Basic Research, project no. 18-53-15006
(in the frames of International Russian-French Program RFBR-CNRS).
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2. I.D. Kovalev, N.A. Kochetov, Mechanical activation-induced structural changes in a 5Ti + 3Si mixture, Inorg. Mater., 2017, vol. 53, no. 4, pp. 447-450.
3. N.A. Kochetov, S.G. Vadchenko, Mechanically activated SHS of NiAl: effect of Ni morphology and mechanoactivation conditions, Int. J. Self-Propag. High-Temp. Synth., 2012, vol. 21, no. 1, pp. 55-58.
