材料显微组织数字化三维重建过程中分辨率的选择

Selection of resolution in digital three-dimensional reconstruction of material microstructure

为合理地、定量化地选择三维重建的分辨率,以规则几何体(球体、八面体)的数字化模型为研究对象,从体积与表面积测量精度角度进行了分析。构建了不同尺寸的球体和八面体的数字化模型,分别利用体素个数计数和移动立方体(marching cube)算法进行体积与表面积的测量。分析表明,对接近球体的物相(如晶粒)而言,为保证其体积测量误差不大于5%,三维重建分辨率应不大于物相直径的1/10。通过测试不同大小规则几何体和不同截面层间距对其体积测量结果精度的影响,得到了系列截面层间距和几何体尺寸对体积测量结果精度的影响规律,可对利用系列截面法进行材料显微组织三维重建时截面层间距的设定提供依据。

In order to choose the resolution of three- dimensional （3D） reconstruction rationally and quantitatively, we used digital models of regular geometries （spheres and octahedrons） as the research objects and analyzed the measurement accuracy of their volume and surface area. We constructed digital spherical and octahedral models of different sizes, and utilized voxel counting and marching cube algo-rithm to measure volume and surface area respectively. From our analysis, for the phase approaching sphere （such as grain） , the 3D reconstruction resolution should be not more than 1/10 of phase diameter to ensure that the volume measurement error is not greater than 5%. We tested the effects of different size regular geometries and different section spacing on the accuracy of volume measurement to obtain the influence law of section spacing and geometrical size on volume measurement accuracy. This can provide the basis for setting section spacing when use serial section technique to reconstruct 3D material microstructure.