Alumina-silicate inclusions (shot) have been found to adversely affect the mechanical properties of a short alumina-silicate fiber reinforced aluminum alloy (A356). To better understand the differences between the responses of the shot and fibers to applied loads, the Young’s modulus of the shot is measured and compared to that of the fibers. The Rayleigh wave speed in the shot particle (cross-sectional area of 200 μm × 150 μm), measured in situ to be 4041 m/s using a scanning acoustic microscope, was used to calculate the Young’s modulus of the shot particle (132 GPa). The accuracy of the technique and the experimental arrangement used was verified to be better than four percent by independent measurements of the Rayleigh wave speeds in the aluminum alloy matrix and an embedded sapphire fiber. The fiber modulus was estimated to be 225 GPa based on a comparison of previously measured composite modulus with micromechanical predictions. Thus, shot was found to have a Young’s modulus 40 percent lower than that of the fibers. The applicability of the V(z) technique has been demonstrated for measuring the elastic properties over a microscopic area, even when the target material is an embedded inclusion.

1.
Bertoni
H. L.
,
1984
, “
Ray-optical Evaluation of V(z) in the Reflection Acoustic Microscope
,”
IEEE Trans. on Sonics and Ultrasonics
, Vol.
SU-31
, No.
2
, pp.
105
116
.
2.
Budiansky
B.
,
1965
, “
On the Elastic Moduli of Some Heterogeneous Materials
,”
Journal of Mechanics and Physics of Solids
, Vol.
13
, pp.
223
227
.
3.
Canumalla
S.
,
Dynan
S. A.
,
Green
D. J.
,
Bhagat
R. B.
, and
Pangborn
R. N.
,
1995
, “
Mechanical Behavior of Mullite Fiber Reinforced Aluminum Alloy Composites
,”
Journal of Composite Materials
, Vol.
29
(
5
) pp.
653
670
.
4.
Canumalla, S., 1995, “Processing and Mechanical Behavior of a Short Fiber Reinforced Metal Matrix Composite,” Doctoral dissertation, The Pennsylvania State University.
5.
Del Grosso
V. A.
, and
Mader
C. W.
,
1972
, “
Speed of Sound in Pure Water
,”
J. Acoust. Soc. Am.
, Vol.
52
, pp.
1442
1446
.
6.
Dynan, S. A., 1992, “Processing and Mechanical Performance of Mutually Interconnected Short Alumina-Silicate Fiber Reinforced A356 Aluminum Composites,” Master of Science thesis in Ceramic Science, Department of Materials Science and Engineering, The Pennsylvania State University.
7.
Farnell, G. W., 1970, “Properties of Elastic Surface Waves,” Physical Acoustics VI, W. P. Mason and R. N. Thurston, eds., Academic Press, New York pp. 109–166.
8.
Hashin
Z. N.
, and
Shtrikman
S.
,
1963
, “
A Variational Approach to the Elastic Behavior of Polycrystals
,”
J. Mech. Phys. of Solids
, Vol.
11
, pp.
127
140
.
9.
Herr
A. E.
,
Canumalla
S.
, and
Pangborn
R. N.
,
1995
, “
Thermal Fatigue Behavior of a Discontinuous, Alumina-Silicate Fiber Reinforced Aluminum Alloy (A356) Composite
,”
Materials Science and Engineering A
, Vol.
200
, pp.
181
191
.
10.
Hill
R.
,
1952
, “
The Elastic Behavior of a Crystalline Aggregate
,”
Proceedings of the Physical Society
, Vol.
65A
, pp.
349
354
.
11.
Hill
R.
,
1965
, “
A Self-consistent Mechanics of Composite Materials
,”
Journal of Mechanics and Physics of Solids
, Vol.
13
, pp.
213
222
.
12.
Hurd
N. J.
,
1988
, “
Fatigue Performance of Alumina Reinforced Metal Matrix Composites
,”
Materials Science and Technology
, Vol.
4
, pp.
513
517
.
13.
Kearney, A. L., 1990, “Cast Aluminum Alloys,” Properties and Selection-Nonferrous Alloys and Special Purpose Metals, Metals Handbook, 10 ed., American Society for Metals, Metals Park, Ohio, pp. 165–166.
14.
Kro¨ner
E.
,
1958
, “
Berechnung der elastischen Konstanten des Vielkristalle aus dem Konstanten des Einkristalls
,”
Z. Phys.
, Vol.
151
, pp.
319
329
.
15.
Kushibiki
J.
, and
Chubachi
N.
,
1985
, “
Material Characterization by Line-focus Beam Acoustic Microscope
,”
IEEE Trans.
, Vol.
SU-32
, pp.
189
211
.
16.
Liu
X. C.
, and
Bathias
C.
,
1993
, “
Fatigue Damage Development in Al2O3/Al Alloy Composite
,”
Composites
, Vol.
24
, No.
3
, pp.
282
287
.
17.
Reuss
A.
,
1929
, “
Berechnung der Fliessgrenze von Mischkristakken auf Grund der Plastizita¨tsbedingung fu¨r Einkristalle
,”
Z. agnew. Math. Mech.
, Vol.
9
, pp.
49
58
.
18.
Sacks
M. D.
,
1991
, “
Advanced Composite Materials
,”
Ceramic Transactions
, Vol.
19
, The American Ceramic Society, pp.
677
693
.
19.
Voight
W.
,
1889
, “
U¨ber die Beziehung zwischen den beiden Elastizita¨tskonstanten isotroper Ko¨rper
,”
Wied. Ann.
, Vol.
38
, pp.
573
577
.
20.
Watt
J. P.
,
Davies
G. F.
, and
O’Connell
R. J.
,
1976
, “
The Elastic Properties of Composite Materials
,”
Rev. of Geophysics Space Physics
, Vol.
14
, No.
4
, pp.
541
563
.
21.
Weglein
R. D.
, and
Wilson
R. G.
,
1978
, “
Characteristic Material Signatures by Acoustic Microscopy
,”
Electron Lett.
, Vol.
14
, pp.
352
354
, June 8.
22.
Weglein
R. D.
,
1985
, “
Acoustic Micro-Metrology
,”
IEEE Trans. on Sonics and Ultrasonics
, Vol.
SU-32
, No.
2
, pp.
225
234
.
23.
Viktorov, I. A., 1967, Rayleigh and Lamb Waves, Plenum Press, New York.
This content is only available via PDF.
You do not currently have access to this content.