【摘要】 用低过热度浇注和弱电磁搅拌工艺制备 A356铝合金半固态浆料,研究了浇注温度、搅拌功率和搅拌时间对 A356铝合金的半固态浆料的影响．结果表明,用该工艺可以制备出球状初生α-Al 晶粒的半固态 A356合金浆料．与单纯低过热度浇注的试样相比较,在弱电磁搅拌条件下,适当提高浇注温度亦可获得理想的球状 A356合金浆料,也简化了实际浇注工艺的操作．低过热度浇注和弱电磁搅拌,加速了合金液向外传热和减小了其温度梯度,扩大了同时凝固的区域,细化了初生α-Al 晶粒,造成的强迫流动,扩大了合金熔体的温度扰动和局部温度起伏,促使初生α-Al 二次臂的熔断和球状初生α-Al 晶粒的形成．更多还原

【Abstract】 The semi-solid slurry of A356 alloy was manufactured by low superheat pouring and weak electromagnetic stirring.The effects of pouring temperature,stirring power and stirring time on the slurry were investigated.The results show that the spherical semi-solid A356 alloy slurry can be prepared through this preparation method and that the proper pouring temperature,stirring power and stirring time are respectively 630℃,136 W and about 3s.When poured under a low superheat and stirred under a weak electromagnetic field,the heat diffusion towards the circumference is strengthened and the temperature gradient in the liquid alloy is decreased greatly,so the solidification region in the same time is enlarged and the primary α-Al grains are fined obviously.Moreover the compelled flow motion in the slurry is caused,and the temperature fluctuation in slurry is promoted,therefore this can cause the secondary arms to be remelted on their roots and the spherical primary α-Al grains are formed in the end.更多还原