Краткое описание

An atomic force microscope has been used to reveal the structure of residual sub-micron size reaction sites in drop weight impacted RDX and in laser heated AP crystals. The smallest reaction sites in impacted RDX were hemispherical craters of 20−300 nm size. On a somewhat larger scale, hillocks of 200−1000 nm were observed, their shape giving evidence of internal reaction and ballooning. At some sites large (1000−3000 nm) volcano-like hot spots from which gases had escaped and where melting had taken place, were observed. Even a mild impact disrupts the periodicity of the RDX lattice, the molecules get displaced from their normal sites by as much as 20 % and sometimes get re-oriented. In AP, laser heating produced cracks and also trumpet shaped 50−200 nm craters, most of which supported a crystallographically oriented square lid on top of them, formed from the wellknown orthorhombic to cubic(rocksalt) phase transition at 240°C.