 | Raha, K. |
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 | Static Charge Development on Explosives
Author : Raha, K. ;Chhabra, J.S.
Source : Defence Science Journal ; Vol:41(1) ; 1991 ; pp 21-25
Subject : 620.261 Explosives
Keywords : Explosives crystals ;Pyroelectric characters ;Ammonium trinitrate
Abstract : Static charge development character of some of the important explosive crystals have been predicted on the basis of their crystal class and symmetry. Among the important mechanism of charge development, the piezoelectric and pyroelectric characters have been considered. Ammonium trinitrate, ammonium nitrate, m-dinitro-benzene, trinitro-toluene, styphnic acid, beeta-lead styphnate, 4,4'dinitro-dipheny1, a-hexamethylenetetranitramine, nitroguanidine, picric acid, dimethylnitramine, a-lead azide and beeta-lead azide are pyroelectric in nature, whereas pentaerythritol tetranitrate, picryliodide, s-hexamethylenetranitramine, tetranitromethane and trinitroethane are piezoelectric in nature. |
| | Piezoelectricity in Single Crystal of Pentaerythritol Tetranitrate
Author : Raha, K. ;Chhabra, J.S.
Source : Defence Science Journal ; Vol:41(3) ; 1991 ; pp 295-304
Subject : 620.261 Explosives ;623.4 Armaments and Ballistics
Keywords : Explosives ;Piezoelectric crystals ;Single crystals
Abstract : The piezoelectric constants perpendicular to (110) and (001) of single crystal f pentaerythritol tetranitrate (PETN) are determined to be (3.2+-0.30)x10/sup-13/and (1.5+-0.30)x10/sub-13/CN/sub-1/. The charge development on these faces under static loading has been confirmed to be true piezoelectric in origin. The crystal seems to experience a quasi permanent deformation under repeated and successive compression with a very long relaxation time. This gives rise to a unique behaviour of individual crystal of PETN under identical stress condition. Mechanical stress relaxation measurements have also been carried out to provide additional evidence on the uniqueness of the crystal. Dielectric constant of the crystal along the directions perpendicular to (110) and (001) are 3.50+-0.12 and 4.57+-0.17; Young's modulus along the directions are (1.24+- 0.30)x10/sub6/g cm/sup-2/ respectively. Single crystals of one cm/sub3/ of PETN develops about 10 V cm/sup-1/ field under a force of 1 kg across (110)face. |
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