In order to improve the mechanical properties at elevated temperatures, several types of steels are mechanically alloyed with yttria. The processes that are active during milling differ dependent on the individual powder constituents. Nevertheless, some theories exist which try to describe the mechanism of producing a metastable phase during milling. However, even in the system iron–yttria, the mechanisms taking place during milling are still not well understood. By using the example of a simple iron–yttria model alloy, this paper attempts to elucidate the structure of mechanically milled powder particles and, consequently, to clarify the functionality of mechanical alloying in the last stage of milling. Positron annihilation experiments on milled materials revealed “open” volumes which are enriched in yttria. Electron backscatter diffraction and atom probe tomography as complimentary techniques allowed an identification of these “open” volumes as mainly vacancies, where enrichments of Y and O occur. From these results, it can be concluded that especially vacancies are responsible for producing a metastable phase, whereby yttria is dissolved in pure iron.

1.
C.
Suryanarayana
,
Prog. Mater. Sci.
46
,
1
(
2001
).
2.
G.
Ressel
,
S.
Primig
, and
H.
Leitner
,
Int. J. Mater. Res.
104
,
1088
(
2013
).
3.
G.
Ressel
,
D.
Holec
,
A.
Fian
,
F.
Mendez-Martin
, and
H.
Leitner
, “
Atomistic insights into milling mechanisms in an Fe-Y2O3 model alloy
,”
Appl Phys. A
(in press).
4.
G.
Ressel
,
S.
Primig
, and
H.
Leitner
,
Metall. Mater. Trans. A
45
,
1552
(
2014
).
5.
M. K.
Miller
,
D. T.
Hoelzer
,
E. A.
Kenik
, and
K. F.
Russell
,
J. Nucl. Mater.
329–333
,
338
(
2004
).
6.
M. K.
Miller
,
K. F.
Russell
, and
D. T.
Hoelzer
,
J. Nucl. Mater.
351
,
261
(
2006
).
7.
A.
Hirata
,
T.
Fujita
,
Y. R.
Wen
,
J. H.
Schneibel
,
C. T.
Liu
, and
M. W.
Chen
,
Nature Mater.
10
,
922
(
2011
).
8.
M.
Klimiankou
,
J. Nucl. Mater.
329–333
,
347
(
2004
).
9.
J.
Roesler
and
E.
Arzt
,
Acta Metall.
36
,
1043
(
1988
).
10.
E.
Arzt
and
J.
Roesler
,
Acta Metall.
36
,
1053
(
1988
).
11.
E.
Arzt
and
D.
Wilkinson
,
Acta Metall.
34
,
1893
(
1986
).
12.
J.
Roesler
and
E.
Arzt
,
Acta Metall. Mater.
38
,
671
(
1990
).
13.
Y.
Ashkenazy
,
N. Q.
Vo
,
D.
Schwen
,
R. S.
Averback
, and
P.
Bellon
,
Acta Mater.
60
,
984
(
2012
).
14.
S.
Odunuga
,
Y.
Li
,
P.
Krasnochtchekov
,
P.
Bellon
, and
R.
Averback
,
Phys. Rev. Lett.
95
,
045901
(
2005
).
15.
N. Q.
Vo
,
S.
Odunuga
,
P.
Bellon
, and
R. S.
Averback
,
Acta Mater.
57
,
3012
(
2009
).
16.
R. B.
Schwarz
,
Mater. Sci. Forum
269–272
,
665
(
1998
).
17.
R.
Schwarz
and
C. C.
Koch
,
Appl. Phys. Lett.
49
,
146
(
1986
).
18.
L. Y.
Pustov
,
S. D.
Kaloshkin
,
V. V.
Tcherdyntsev
,
I. A.
Tomilin
,
E. V.
Shelekhov
, and
A. I.
Salimon
,
Mater. Sci. Forum
360–362
,
373
(
2001
).
19.
M. K.
Miller
and
K. F.
Russell
,
Ultramicroscopy
107
,
761
(
2007
).
20.
M. K.
Miller
,
K. F.
Russell
, and
G. B.
Thompson
,
Ultramicroscopy
102
,
287
(
2005
).
21.
W.
Puff
,
H.
Rabitsch
,
G.
Wilde
,
G. P.
Dinda
, and
R.
Wuürschum
,
J. Appl. Phys.
101
,
123512
(
2007
).
22.
W.
Puff
,
Comput. Phys. Commun.
30
,
359
(
1983
).
23.
A.
Somoza
,
M.
Petkov
,
K.
Lynn
, and
A.
Dupasquier
,
Phys. Rev. B
65
,
094107
(
2002
).
24.
M. J.
Puska
,
P.
Lanki
, and
R. M.
Nieminen
,
J. Phys. Condens. Matter
1
,
6081
(
1989
).
25.
B.
Oberdorfer
and
R.
Würschum
,
Phys. Rev. B
79
,
184103
(
2009
).
26.
W.
Puff
,
X.
Zhou
,
B.
Oberdorfer
,
B.
Scherwitzl
,
P.
Parz
,
W.
Sprengel
, and
R.
Würschum
,
J. Phys. Conf. Ser.
443
,
012033
(
2013
).
27.
O. C.
Hellman
,
J. B.
du Rivage
, and
D. N.
Seidman
,
Ultramicroscopy
95
,
199
(
2003
).
28.
O. C.
Hellman
,
J. A.
Vandenbroucke
,
J.
Rüsing
,
D.
Isheim
, and
D. N.
Seidman
,
Microsc. Microanal.
6
,
437
(
2000
).
29.
T. E. M.
Staab
,
R.
Krause-Rehberg
, and
B.
Kieback
,
J. Mater. Sci.
34
,
3833
(
1999
).
30.
H.
Schaefer
,
R.
Würschum
,
R.
Birringer
, and
H.
Gleiter
,
Phys. Rev. B
38
,
9545
(
1988
).
31.
A.
Vehanen
,
P.
Hautojärvi
,
J.
Johansson
,
J.
Yli-Kauppila
, and
P.
Moser
,
Phys. Rev. B
25
,
762
(
1982
).
32.
C.
Hidalgo
,
G.
González-Doncel
,
S.
Linderoth
, and
J.
San Juan
,
Phys. Rev. B
45
,
7017
(
1992
).
33.
H. E.
Schaefer
and
R.
Würschum
,
Phys. Lett. A
119
,
370
(
1987
).
34.
H. F. M.
Mohamed
,
J.
Kwon
,
Y.-M.
Kim
, and
W.
Kim
,
Nucl. Instrum. Methods Phys. Res., Sect. B
258
,
429
(
2007
).
35.
J.
Kuriplach
,
O.
Melikhova
,
M.
Hou
,
S.
Van Petegem
,
E.
Zhurkin
, and
M.
Šob
,
Phys. Status Solidi
4
,
3461
(
2007
).
36.
J.
Kuriplach
,
O.
Melikhova
,
M.
Hou
,
S.
Van Petegem
,
E.
Zhurkin
, and
M.
Šob
,
Appl. Surf. Sci.
255
,
128
(
2008
).
37.
P.
Hautojärvi
,
J.
Johansson
,
A.
Vehanen
,
J.
Yli-Kauppila
, and
P.
Moser
,
Phys. Rev. Lett.
44
,
1326
(
1980
).
38.
M. J.
Puska
and
R. M.
Nieminen
,
J. Phys. F: Met. Phys.
13
,
333
(
1983
).
39.
J. H.
Lee
,
J. Nanosci. Nanotechnol.
12
,
1670
(
2012
).
40.
M. J.
Alinger
,
S. C.
Glade
,
B. D.
Wirth
,
G. R.
Odette
,
T.
Toyama
,
Y.
Nagai
, and
M.
Hasegawa
,
Mater. Sci. Eng. A
518
,
150
(
2009
).
41.
S.
Pogatscher
,
H.
Antrekowitsch
,
H.
Leitner
,
T.
Ebner
, and
P. J.
Uggowitzer
,
Acta Mater.
59
,
3352
(
2011
).
42.
A.
Kelly
and
R. B.
Nicholson
,
Prog. Mater. Sci.
10
,
151
(
1963
).
43.
E. V.
Pereloma
,
I. B.
Timokhina
,
J. J.
Jonas
, and
M. K.
Miller
,
Acta Mater.
54
,
4539
(
2006
).
44.
Y.
Chen
and
C. A.
Schuh
,
Scr. Mater.
57
,
253
(
2007
).
45.
P.
Stender
,
Z.
Balogh
, and
G.
Schmitz
,
Ultramicroscopy
111
,
524
(
2011
).
46.
D.
Raabe
,
S.
Sandlöbes
,
J.
Millán
,
D.
Ponge
,
H.
Assadi
,
M.
Herbig
, and
P.-P.
Choi
,
Acta Mater.
61
,
6132
(
2013
).
You do not currently have access to this content.