|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Fundamental Aspects and Modeling Powder Metal Synthesis and Processing
||Dislocation Density Approach to Understanding Sintering Mechanics
||Chaoyi Zhu, Diletta Giuntini, Tyler Harrington, Eugene Olevsky, Kenneth Vecchio
|On-Site Speaker (Planned)
Understanding of how dislocations accumulate in the sintered particles is fundamental to shrinkage kinetics. Based on bulk and pipe diffusivity data from the literature, Olevsky <I>et al.</I>’s theoretical model relates dislocation density to shrinkage rates. Experimentally, nanoindentation allows determination of the total dislocation density, comparable with theoretical predication, including statistically stored dislocation (SSD) and geometrically necessary dislocations (GND). Utilizing Nye’s tensor, we are able to separate out the geometrically necessary part of the total dislocation density present to accommodate lattice curvature using EBSD based computational methods. In this study, GND density data validates the nanoindentation result and reconfirm that the theoretical predication of dislocation density is higher in the compaction plane than the compaction direction of powder compacts. In addition, detailed information about GND dislocation structure can be mapped to the sintered particles, which sheds light on the micromechanics of the sintering process.