【摘要】 在不同的恒温条件下,对Al-Si合金熔体进行不同时间的超声处理,当超声处理时间为60 s时,试样含气量显著降低,除气效果明显.在Al-Si合金凝固过程中施加超声场,晶粒发生球化、细化现象;在Al-Si合金凝固区间恒温条件下施加超声场,晶粒发生细化但未发生球化现象.超声场作用下Al-Si合金晶粒细化主要是由于空化泡破碎产生的过冷生核所造成的.更多还原

【Abstract】 Under different constant temperatures a Al-1%Si alloy(mass fraction)melt was treated by ultrasound field.The gass content in Al-Si melt decreased obviously when the treated time is 60 s.The grains are refined and globularization when the Al-Si melt was solidified under ultrasound but the grains only are refined when solidified at isothermal temperature in the mushy zone with ultrasonic vibrations.The results imply that the expansion and collapse of cavities which results in the formation of nuclei play the important role in the formation of fine and globular grains.更多还原