Critical stress intensity for off-axis fracture of Al 2 O 3 fiber reinforced magnesium
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Critical Stress Intensity for Off-Axis Fracture of AI203 Fiber Reinforced Magnesium
[2] Thus, the experimental value (Eq. [1]) of the magnetization amounts to 95 pct of the theoretically possible value (Eq. [2]). The 5 pct difference may be due either to the errors involved in the estimation of numerical values or to the possible existence of remaining untransformed particles. Since Msexp is very close to M ~ e~ this strongly supports the conclusion that once martensitic transformation takes place in Fe particles surrounded by a Cu matrix, the entire volume of the particles becomes micro-twinned a-Fe. This is because if plastic deformation should induce partial transformation of Fe particles with a banded structure of alternating layers of y-and a-Fe of approximately equal volume, as has been suggested by others, 1'2'7'8M~xp can not be larger than half of the theoretical value, Mt~e~ It may be argued that prohibitively large elastic strain energy may be associated with a fully transformed a-Fe particle, and this may affect the result. We feel that, even in the fully transformed particle, the elastic strain energy can drastically be reduced by the occurrence of micro-twinning in the a-Fe particle. 6'14 This research note is a portion of a joint research effort of the Materials Research Laboratory group at Michigan State University. Use of the SQUID facility and other related facilities in the Physics Department is gratefully acknowledged. Two of the authors (M. K. and C. T.) would also like to acknowledge partial support of this work through the All University Research Initiation Grant.
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K. S. CHAN, J.E. HACK, and R. A. PAGE While studying the fracture behavior of fiber-reinforced composite materials a number of investigators ~-6 have concluded that Kc, the critical stress intensity factor, is a material parameter and as such should be useful for design purposes. These studies have also established that,
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