Growth And Mechanical Properties Of Filamentary Silicon Carbide Crystals
Report Number: WADD TR 61-252
Author(s): Yerkovtich, Luke A., Kirchner, Henry P.
Corporate Author(s): Cornell Aeronautical Laboratory, Inc.
Laboratory: Nonmetallic Materials Laboratory
Date of Publication: 1961-08
Pages: 38
Contract: AF 33(616)-7005
DoD Project: 7340
DoD Task: 73400
Identifier: AD0273997
Abstract:
In this investigation silicon carbide whiskers were grown under various experimental conditions. The strength and modulus of elasticity of several whiskers were determined at room temperature. Methods of heating the whiskers for high temperature measurements were investigated. The specific gravity of the whiskers was inferred from measurement of the unit cell dimensions by X-ray diffraction patterns. Silicon carbide whiskers were grown by pyrolysis of methyltrichlorosilane in hydrogen. In some cases dense growths of whiskers from 1.2 to 1.5 centimeters in length and from 2 to 5 microns in diameter were observed. The longest whisker obtained, thus far, was 5 centimeters in length. The tensile strength ranged from 100,400 to 1,650,000 psi. The elastic strain at failure varied from 0.41 to 1.10 per cent and the observed values of elastic modulus varied from 12,700,000 to 123,300,000 psi. These results indicate that silicon carbide whiskers can be strong, high modulus of elasticity materials. Much research needs to be done to improve the methods of measurement, and to define the conditions of measurement and the types of whiskers that will give the best performance as structural materials.
Provenance: Lockheed Martin Missiles & Fire Control
Author(s): Yerkovtich, Luke A., Kirchner, Henry P.
Corporate Author(s): Cornell Aeronautical Laboratory, Inc.
Laboratory: Nonmetallic Materials Laboratory
Date of Publication: 1961-08
Pages: 38
Contract: AF 33(616)-7005
DoD Project: 7340
DoD Task: 73400
Identifier: AD0273997
Abstract:
In this investigation silicon carbide whiskers were grown under various experimental conditions. The strength and modulus of elasticity of several whiskers were determined at room temperature. Methods of heating the whiskers for high temperature measurements were investigated. The specific gravity of the whiskers was inferred from measurement of the unit cell dimensions by X-ray diffraction patterns. Silicon carbide whiskers were grown by pyrolysis of methyltrichlorosilane in hydrogen. In some cases dense growths of whiskers from 1.2 to 1.5 centimeters in length and from 2 to 5 microns in diameter were observed. The longest whisker obtained, thus far, was 5 centimeters in length. The tensile strength ranged from 100,400 to 1,650,000 psi. The elastic strain at failure varied from 0.41 to 1.10 per cent and the observed values of elastic modulus varied from 12,700,000 to 123,300,000 psi. These results indicate that silicon carbide whiskers can be strong, high modulus of elasticity materials. Much research needs to be done to improve the methods of measurement, and to define the conditions of measurement and the types of whiskers that will give the best performance as structural materials.
Provenance: Lockheed Martin Missiles & Fire Control