Quantitative serial sectioning analysis

A method for serial sectioning is presented that allows one to take about 20 sections per hour with spacings in the range 1-20 mum between sections. The alignment of the cross-sections is done with a linear variable differential transformer; it is thus independent of the microstructure of the sample and does not rely upon markers implanted in the sample. The alignment errors as well as tilts and rotation errors between sections associated with the new method are found to be negligible. Once all the sections are captured in a computer a three-dimensional image can be constructed. This image can be viewed interactively and rotated, thus allowing the direct observation of three-dimensional shapes. It can further be used to determine a vast array of microstructural parameters including those that cannot be determined from planar sections. The technique is illustrated through the reconstruction of the microstructure of a cast standard aluminium alloy specimen.