Abstract
Elemental tungsten powder was mechanically milled by planetary mill for 100 h. Particles were thinned down to nanometre scale. The shape of the milled powders was flat cylindrical with average diameter and length 12˙5 and 46˙5 nm respectively. The corresponding crystallite size obtained by X-ray diffraction (XRD) was 26˙96 nm. The results obtained by XRD and small angle X-ray scattering were well supported by transmission electron microscopy and high resolution transmission electron microscopy results. The maximum shrinkage of the compact has been observed at ∼1500 K, which has been used as a guideline for sintering experiments. The powders sintered at 1773 K have resulted in 96% relative density.
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References
1.
Smith
W. F.
: ‘Structure and properties of engineering alloys’, 2nd edn; 1993, Singapore, McGraw-Hill.
2.
Bose
A.
and
German
R. M.
in ‘Sintering technology’, (ed.
German
R. M.
et al), 269-276; 2000, New York, Mercel Dekker Inc.
3.
Wu
Y.
,
German
R. M.
,
Marx
B.
,
Bollina
R.
and
Bell
M.
Mater. Sci. Eng. A , 2003 , A344 , 158 –167 .
4.
Ryu
H. J.
,
Hong
S. H.
and
Baek
W. H.
J. Mater. Process Technol , 1997 , 63 , 292 –297 .
5.
Ryu
H. J.
,
Hong
S. H.
and
Back
W. H.
Mater. Sci. Eng. A , 2000 , A291 , 91 –96 .
6.
Suryanarayana
C.
: ‘Mechanical alloying and milling’ ; 2004 , New York , Marcel Dekker .
7.
Malewar
R.
,
Kumar
K. S.
,
Murty
B. S.
,
Sarma
B.
and
Pabi
S. K.
J. Mater. Res ., 2007 , 22 , 1200 –1206 .
8.
German
R. M.
and
Olevsky
E.
Int. J. Refract. Met. H ., 2005 , 23 , 294 –300 .
9.
German
R. M.
and
Olevsky
E.
Int. J. Refract. Met. H ., 2005 , 23 , 77 –84 .
10.
Oda
E.
,
Ameyama
K.
and
Yamaguchi
S.
Mater. Sci. Forum , 2006 , 503-504 , 573 –578 .
11.
Jang
J. S. C.
,
Fwu
J. C.
,
Chang
L. J.
,
Chen
G. J.
and
Hsu
C. T.
J. Alloys Compd , 2007 , 434-435 , 367 –370 .
12.
Huang
B.
,
Fan
J.
,
Liang
S.
and
Qu
X.
J. Mater. Process Technol , 2003 , 137 , 177 .
13.
Ozawa
E.
,
Kawakami
Y.
and
Scr
T.
Scr. Mater ., 2001 , 44 , 2279 –2283 .
14.
Metal-powder
MPR
.net , December 2006 , 16.
15.
Nersisyan
H. H.
,
Lee
J. H.
and
Won
C. W.
Combust. Flame , 2005 , 142 , 241 –248 .
16.
Ghosal
P.
,
Singh
A. K.
,
Bagchi
T. P.
,
Sarma
B.
and
Maitra
N.
Powder Metall , 2006 , 49 , 224 –235 .
17.
Cullity
B. D.
: ‘Elements of X-ray diffraction’, 2nd edn; 1978, Reading, MA, Addition-Wesley Publishing Company Inc.
18.
Young
R. A.
: ‘The rietveld method’ ; 2000 , IUCR , Oxford Science Pub .
19.
Oldani
C.
and
Silvetti
S. P.
Scr. Mater ., 2000 , 43 , 129 –134 .
20.
Dutta
H.
,
Sahu
P.
,
Pradhan
S. K.
and
De
M.
Mater. Chem. Phys ., 2002 , 77 , 153 –164 .
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