The heredity and control of microstructures of liquid metals during rapid cooling processes

An investigation of the heredity and control of the microstructures of liquid metals during rapid cooling processes has been performed under different conditions by molecular dynamics simulations. Some important results have been obtained. Firstly, in the liquid metal system, the choice of which atom becomes the central atom of a small cluster is accidental and random. However, as long as a small cluster has been formed with a given atom as the center and some surrounding atoms, the cluster could be repeated with the same central atom and the same surrounding atoms again and again during the runs. The clusters would possess relative stability during the isothermal processes and heredity (continuity) during the rapid cooling processes. The stability and heredity of icosahedral clusters can be expressed quantitatively by their lifetime or repeatable times. In general, the lifetimes of these clusters increase with decreasing temperature, especially below the glass transition temperature T/sub g/. The number of clusters having a longer lifetime also increases with decreasing temperature. These will give a new way of understanding and controlling the heredity and transition mechanisms of microstructures of liquid and solid metals.