Microstructure Formation in Rapidly Solidified Alloys

摘要: In order to apply solidification theory the interpretation of micro- structures produced by rapid solidification, several modifications are required. Different degrees non-equilibrium occur during and constitute a hierarchy which is followed with increasing rate. Analytical expressions given for model interface conditions describe temperatures compositions at liquid solid as function velocity. For intermediate veloicities (≃10 cm/s) assumption local interfacial equilibrium remains valid but microstructures often under where solute Peclet number Pc= V1/2D, greater than one. The parameters V, 1 D velocity, relevant microstruetural length scale diffusion coefficient respectively. This fact requires that topics in be modified. Such modification presented alloy dendritic growth theory. alloys solidifying dendritically into undercooled melts, redistribution dominates relatinship between rate initial undercooling when smaller freezing range (difference liquidus solidus temperatures). has important consequences eutectic coupled zone boundaries arrayed growth.