Experimental study on thermal damage characterization of RDX-based PBX after high-temperature treatment
The thermal damaged features and evolution behaviors of High Explosives(HEs)has an important effect on their safety.To investigate the internal damage and evolution behavior of RDX(1,3,5-trinitro-l,3,5-triazinane)-based Polymer Binder Explosive(PBX)under different temperature loads(unheated,140 ℃,160 ℃,180 ℃ for 40 h),an unconstrained cook-off experiment was designed.Throughout the experiment,the mass change of the explosives was monitored through balance analysis to determine the law of mass loss under high-temperature loading conditions.Optical microscopy and scanning electron microscopy were used to observe the surface of the explosive and obtain information on its damage evolution.Micro-CT was used to characterize the internal structural damage of the explosive.Results show that the higher the loading temperature,the greater the mass loss and mass loss rate of the explosive.At 140 ℃,the binder melts,and with increasing temperature,the degree of binder melting increases while the fluidity is enhanced.At 180℃,the binder and RDX crystals become mixed,such that the boundary can not be distinguished between the two.Gas escaped from the holes on the surface of the explosive,and the binder formed a bubble-like structure.As temperature increases,the number and size of surface holes in the explosive also increase.The amount and size of voids inside the explosive increase with increasing temperature,which are largely formed by gas escaping from the interior of the sample.The variance law of the specific surface area inside the explosive changes from up-down-up and is influenced by the chemical reaction rate and the flow and loss of the binder.The thermal stability of binder materials is an important factor affecting the evolution behaviour of thermal damage of explosives.Therefore,improving the thermal stability of binder materials is particularly important for reducing the thermal sensitivity of explosive materials.
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万方数据
维普
