An investigation on supercooling directional solidification process of Cu-Ni single phase alloy

Supercooling directional solidification (SDS) is put forward by combination of melt supercooling and conventional solidification by application of sup ercooling inheritance. On the self-designed SDS equipment, SDS of Cu-Ni all oy was achieved successfully. The results are as follows: (i) The primary a rm spacing is about 30 mu m, the growth of secondary arms are strongly supp ressed. The primary arm spacing is nearly the same as LMC method (G(L)=25 K /mm, V=500 mu m/s), the primary stems are straight, fine and completed, wit h an inclination angle of about 5.8 degrees. (ii) A semi-quantitative T-T m odel is brought forward to describe the dendrite growth rate V vs. undercoo ling Delta T. The prediction of T-T model agrees well with experimental res ults. The formation of fine equiaxed dendrites, transition region and dendr ite region can be explained successfully by Delta T-V-x relation of T-T mod el.