HMX和RDX晶体微细结构μCT表征

Characterization on Microscopic Structures of HMX and RDX with μCT

利用微焦点CT技术研究了HMX和RDX单晶体和松装大量RDX晶体的微细结构,得到了炸药晶体的三维细微形貌、内部孔隙的定位定量、密度分布等信息,结果显示,结晶品质好的单晶体外观棱角分明,晶面光洁,内部密度均匀,但也有很多微孔隙;而结晶品质较差的单晶体的表面不光滑,棱角不明显,内部孔隙数量多,有较大体积的孔洞,而且密度分布不均匀,有局部密度较高的区域。松装大量炸药晶体平均孔隙率及孔隙数量分布统计表明,经过特定工艺处理过的高品质与其原料相比在各个缺陷大小范围内数量减少,孔隙率减小;在一定程度范围内,越小的孔洞数量越多,但对整个晶体的孔隙率影响越来越小,说明晶体内部微米级以上孔隙是影响晶体密度及其它性能的很重要的因素。

The microscopic structures of typical crystal explosives （HMX and RDX） were studied including single crystals and loose stacked crystal particles with microfocus X-ray industrial volume computed tomography （uCT）. The structure information has been obtained such as nice appearance,intragranular cavities and density distribution. Results show that the high quality crystal has clear edges and corners,the crystal surface is smooth and the interior density is homogeneous but many tiny cavities in it. The surface is rough and the edges and corners are not clear for the low quality of HMX and RDX. Furthermore,the number of interior cavities is big and the density is not well-distributed and high density localities usually exist. The statistical results indicate that the cavity ratio and quantities decrease for recrystallized RDX（D-RDX） to normal RDX（N-RDX） and the less the cavities the more the amount to some degree but very small in the cavity ratio,and illustrate that level cavities greater than micron are important factor for crystal density and other performance.