The dendrite structure characteristics

mechanical properties and forming conditions of Al-35La alloy prepared by directional solidification were investigated.The results show that the dendrite structure in Al-35La alloy obtained by directional solidification exhibits discontinuous and periodic two-phase morphology along the main body.The mechanic properties testing shows that the samples obtained exhibit higher compression strength and hardness.Formation mechanism of the periodic two-phase dendrite structure in Al-35La alloy was described.Convection with a certain intensity will take off crystallization latent heat in the liquid by promoting solute exchanging during nucleation and growth of dendrite.Therefore

it is considered that the convection with a certain intensity will promote the alternately nucleation and growth of two phase in the liquid of Al-35La alloy

resulting in the formation of periodic two-phase dendrite structure in the alloy.