Abstract
The fracture strength in tension of nominally 0.026 cm diameter c-axis sapphire filament grown from the melt using the “edge-defined, Film-fed Growth” technique is presented. The strength is found to be a function of filament diameter, decreasing with decreasing diameter. This relationship is explained on the basis of the particular characteristics of the melt growth preparation method. A melt temperature controlling device, dependent on the infra-red emitted from the melt area at which the filament is withdrawn, was developed and used to grow filament of constant diameter in the growth rate range 2.5 to 7.5 cm/min. With this device strength is not found to vary significantly with growth rate. Average strengths in tension of 2.75×109 N/m2 (400×103 lb f/in.2) are reported using this temperature controlling method compared with 2.5×109 N/m2 (360×103 lb f/in.2) for similar diameter material grown using a constant power mode system.
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References
H. E. Labelle, Jun and A. I. Mlavsky, Mater. Res. Bull. 6 (1971) 571.
H. E. Labelle, Jun, ibid 6 (1971) 581.
B. Chalmers, H. E. Labelle, Jun, and A. I. Mlavsky, ibid 6 (1971) 681.
H. E. Labelle, Jun and J. T. A. Pollock, ibid to be published.
H. E. Labelle, Jun and G. F. Hurley, SAMPE 6 (1970) 17.
J. T. A. Pollock, J. Mater. Sci. 7 (1972) 631.
J. B. Wachtman, W. E. Tefft, D. G. Lam, and R. P. Stinchfield, J. Res. Nat. Bur. Stand. 64A (1960) 213.
R. P. Nelson, Battelle North-West, private communication. μ=0.7 poise at the melting point, 2057°C. μ=0.4 poise at 2650°C
J. T. A. Pollock and G. F. Hurley, submitted for publication.
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Pollock, J.T.A. Filamentary sapphire. J Mater Sci 7, 649–653 (1972). https://doi.org/10.1007/BF00549376
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DOI: https://doi.org/10.1007/BF00549376