R.H. FOLK II, M. KHANTHA, D.P. POPE, V. VITEK, "Temperature-Dependent Onset of Yielding in Dislocation-Free Silicon: Evidence of a Brittle-to-Ductile Transistion", pp.161-167.

R.H. FOLK II, M. KHANTHA, D.P. POPE, V. VITEK, "Temperature-Dependent Onset of Yielding in Dislocation-Free Silicon: Evidence of a Brittle-to-Ductile Transistion", pp.161-167. Copyright - [Précédente] [Première page] [Suivante] - Home

Article : [SHEET412]

Titre : R.H. FOLK II, M. KHANTHA, D.P. POPE, V. VITEK, Temperature-Dependent Onset of Yielding in Dislocation-Free Silicon: Evidence of a Brittle-to-Ductile Transistion, pp.161-167.

Auteur : R. H. Folk II
Auteur : M. Khantha
Auteur : D.P. Pope
Auteur : V. Vitek - Dept. of Materials Science and Eng., University of Pennsylvania, Phila. Pa., 19072

Stockage : Stéphane FORSTER et Thierry LEQUEU
Pages : 161 - 167

ABSTRACT :
An investigation of the brittle-to-ductile transition (BDT) in silicon has been conducted on essentially dislocation-free
silicon test specimens made by photolithography. No pre-cracks or additional dislocation sources were introduced into the
samples. Three-point bending tests of the samples reveals a well defined transition from brittle fracture of the specimens
to complete yielding near 732°C at a crosshead displacement rate of 0.1 mm/min. Limited plasticity is observed below 732°C
but is insufficient to prevent crack propagation suggesting that yielding is not dislocation mobility limited. Instead the
transition may be controlled by the nucleation of a sufficient density of dislocations. Further support comes from the
results of experiments conducted at temperatures below 732°C in which samples were rapidly pre-loaded within the linearly
elastic regime, then immediately retested. This rapid pre-loading results in a lower transition temperature. This would not
be expected if dislocation mobility controlled the BDT. Instead, it is believed that the transition only occurs when a
sufficient density of dislocations has nucleated within the sample. In these experiments, the pre-loading event may increase
the dislocation nucleation rate. The source of the dislocations in these defect free samples is still under investigation.

REFERENCES : 7
[1] : P. B. Hirsch, F. R. S., S. G. Roberts, and J. Samuels, Proc. R. Soc. Lond. A421, pp. 25-53 (1989).
[2] : M. Brede, Acta Metall. Mater. 41, No.l, pp. 211-228 (1993).
[3] : V. R. Nitzsche and K. J. Hsia, Mat. Sci. and Eng. A176, pp. 155-164 (1994).
[4] : G. L. Pearson, W. T. Read Jr., and W. L. Feldmann, Acta Met. S, pp. 181-191 (1957).
[5] : S. S. Brenner, J. Applied Phy., 27, No.12, pp. 1484-1491 (1956).
[6] : S. S. Brenner, J. Applied Phy., 28, No.9, pp. 1023-1026 (1957).
[7] : J. R. Patel and A. R. Chaudhuri, J. Applied Phy., 34, No.9, pp. 2788-2799 (1963).

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