Computer simulation of the aggregation and sintering restructuring of fractal-like clusters containing limited numbers of primary particles

A random particle computer simulation (in three dimensions) was conducted t o investigate the structure and aggregation characteristics of small cluste rs (containing limited numbers of primary particles per cluster). Though an individual cluster of small size does not satisfy the power law, it was fo und that these aggregated clusters are fractal-like and comply with the fra ctal power law form in a statistical sense. This statistically averaged fra ctal dimension decreases as the clusters become smaller. A cluster-restruct uring model is further developed to simulate the topological evolution of d endritic structured materials due to sintering at high temperatures. Result s indicate that the cluster fractal dimension increases as sintering procee ds for small clusters, in contrast to results for large clusters wherein th e topology is retained and the fractal dimension remains constant. A relati onship of the fractal dimension change with the normalized surface area of dendrites for different-sized clusters is established. (C) 1999 Academic Pr ess.