EBSD analysis of spark plasma sintered SS316-B₄C composite

Prior research has shown that sintering processes influence grain structure and mechanical properties in metal composites. It was already known that Spark Plasma Sintering (SPS) allows for precise control of microstructural evolution. However, the specific effects of carbon content and sintering temperature on grain boundary behavior remain unclear. No prior work had resolved how twin boundary migration and grain recrystallization change with carbon addition. This gap motivated a closer look at how microstructural changes are captured using EBSD in SS316-B4C composites. The uncertainty around optimal sintering temperatures for microstructural homogeneity drove the need for detailed EBSD analysis. Existing studies have not fully explained the interplay between carbon content and grain boundary dynamics during SPS. That uncertainty drove the current investigation into how B4C affects grain evolution in SS316.

The aim of this study was to evaluate how sintering temperature affects the microstructural evolution of SS316-B4C composites using EBSD. The specific problem addressed is the lack of understanding about how carbon content influences grain boundary migration and twin boundary formation. The motivation comes from the need to optimize sintering parameters for improved mechanical properties. The researchers propose that EBSD can provide detailed insights into grain orientation and boundary behavior. The study focuses on comparing samples sintered at 800, 900, and 1000°C to identify optimal conditions. The goal is to determine how B4C addition and sintering temperature affect grain structure homogeneity. The researchers propose that EBSD can differentiate between recrystallized and sintered grains using GOS maps. The study aims to clarify the role of carbon in grain boundary dynamics during SPS.

The study used Electron Backscatter Diffraction (EBSD) to analyze microstructural changes in SS316-B4C composites. Spark Plasma Sintering (SPS) was employed to fabricate samples with 10 wt% B4C at 800, 900, and 1000°C. The EBSD method was applied to capture misorientation diagrams, pole figures, and grain size distribution. The samples were analyzed for equiaxed and elongated grain structures post-sintering. Grain Orientation Spread (GOS) maps were used to partition microstructural regions. The study compared grain boundary migration and twin boundary formation across temperature conditions. The researchers propose that EBSD can distinguish between recrystallized and sintered grains. The experimental setup focused on tracking how carbon content affects grain boundary behavior.

The samples sintered at 900°C showed the highest degree of recrystallization compared to those at 800 and 1000°C. The grain structure was more equiaxed and homogeneous at 900°C. At 800 and 1000°C, the microstructure was partially recrystallized with elongated grains. The EBSD analysis revealed that increasing carbon content reduced grain boundary migration. The twin boundary generation rate was also reduced with higher carbon content. The loss of twin character was accelerated due to low-angle boundary formation. The drag effect caused by carbon addition led to smaller dynamically recrystallized grains. The GOS maps effectively differentiated sintered and recrystallized grain regions.

The authors propose that EBSD is a valuable tool for analyzing microstructural evolution in SS316-B4C composites. The results suggest that sintering at 900°C produces the most favorable microstructure. The researchers propose that carbon content influences grain boundary migration rates. The study suggests that higher carbon content accelerates twin character loss. The drag effect caused by carbon addition reduces grain size during recrystallization. The GOS maps effectively partitioned sintered and recrystallized grain regions. The findings suggest that EBSD can distinguish between different grain structures. The study concludes that EBSD provides detailed insights into grain boundary behavior during SPS.