Three-Dimensional Reconstruction of Friction Stir Welding Microstructure via Serial Sectioning

Three-Dimensional Reconstruction of Microstructures is one of the tools to
reveal the patterns, shape, area that affected by processing condition. The objectives
of this project are to perform serial sectioning as one of the technique of threedimensional
microscopy to generate three-dimensional microstructure image and to
characterize the effect of friction stir welding on silicon carbide aluminum reinforced
microstructure Friction stir welding (FSW) has been successfully used to join
aluminum matrix composites in a solid state joining process. The study of the
microstructure of the weld joint typically involved common metallography
preparation techniques, culminating in two-dimensional micrographs depicting the
microstructure of the weld joint. The techniques of serial sectioning and threedimensional
reconstruction were employed to characterize the microstructure of
silicon carbide (SiC) reinforced aluminum composite joined via the FSW process.
Serial sectioning tasks were performed using conventional metallography techniques
and equipment; however micrographs of the composite were recorded after each
successive polishing step. Using the open source software NIH ImageJ, these
micrographs were digitally enhanced and stacked to generate a 3D volume of the
composite. The 3D reconstructions showed that a portion of the initial SiC particles
were broken up by the FSW process and redistributed in the weld zone. Furthermore,
the FSW process appeared to cause some of the unbroken SiC particles to align
lengthwise in the welding direction. These characteristics would definitely influence
the mechanical behaviour of the weld joint and future work will include the effects of
welding parameters on the size and distribution of the SiC particles within the weld
zone.