TATB造型颗粒模压结构演变的X射线层析成像

X-ray Tomography of Structural Evolution of TATB Granules During Compaction

利用X射线层析成像技术结合内置变形材料的形变特征,研究了TATB造型颗粒压制过程中颗粒变形和结构演变。CT图像显示：中部颗粒主要发生向下的压实变形,模具壁附近颗粒向下压实同时还会发生拱起变形;孔隙率变化主要发生在压制初期,即0~10 MPa压力下,上、中、下各部位（分别距顶面5,20,35 mm处）孔隙率分别减少了73%,62%和58%,压制各阶段孔隙率沿轴向由上至下递增;颗粒主要在压制方向（轴向）发生位移,模具与颗粒间的摩擦力大于颗粒间摩擦力,中部的颗粒向下发生较大位移。结果表明,X射线层析成像可无损表征造型颗粒受压过程内部结构演变,颗粒形态变化和相互接触关系揭示了受压颗粒间作用模式,颗粒位移间接反映了炸药内部应力传递情况。

The triamino trinitrobenzene（ TATB） granule deformation and structural evolution during compaction process were studied by x-ray tomography technology and deformation characteristics of deformable material. The CT images show that the deformation orientations of granules in the central part are mostly downwards. In the meanwhile,there are arching between the granules near the edge of mould. The porosity changing mainly happens in the initial stage of compaction with the forming pressures of 0 MPa to 10 MPa,and the porosity of each part（ 5,20,35 mm away from the top surface） decreases 73%,62% and 58%,respectively. During each compaction process,the porosity increases from the top down and the displacements mainly take place along the axial direction. Friction between the mould and granule is greater than that between the granules,which makes the displacements of the granules in the central part larger than granules at other parts. Results show that X-ray tomography can nondestructively characterize inner structural evolution of TATB granules during compaction. Morphology changes and contact relations of granules reveal the interaction mode between the granules. The displacements of granules indirectly reflect the internal stress transfer in the explosive.