Effect of cluster deposition on the eutectic structure in binary systems: A Monte-Carlo simulation

The dynamic evolution of the lamellar eutectic of binary alloys in directional solidifications was studied in detail using the Monte-Carlo technique. In our simulation, the solidification is executed by individual A and B atoms (Case I) and individual A atoms and AB dimers (Case II). We can find: (1) the off coupled eutectic pattern occurs easily in Case II by introducing the cluster deposition; (2) the fluctuation of branching degree (Db) of the lamella in Case II is larger than Case I; (3) the simulated tendency for the formation of the off-coupled and branched structures accords with the experimental results in the Al-Cu alloys and Al-Si alloy.