半固态搅拌参数对A356-10%B4Cp复合材料显微组织的影响

Effect of Parameters of Semi-solid Stirring on Microstructure of A356-10%B4Cp Composites

本工作采用一种半固态搅拌与热轧工艺制备A356-10%B 4C p(质量分数,下同)复合板材,研究了半固态搅拌参数对A356-10%B 4C p复合材料铸造及热轧态显微组织的影响。研究发现:搅拌温度为580℃、搅拌时间为15 min、搅拌转速在800 r/min以内时,α-Al的晶粒平均直径和平均圆度随着搅拌速度的增加而减小,B 4C颗粒的分布也随之更加均匀。当搅拌转速超过800 r/min时,α-Al晶粒平均直径和平均圆度反而不再减小,且B 4C颗粒的分布不均匀。当搅拌温度为580℃、搅拌转速为800 r/min、搅拌时间在5~35 min内时,α-Al晶粒平均直径和平均圆度随着搅拌时间的延长而减小,B 4C颗粒的分布也随之均匀。优化的工艺参数为:搅拌温度为580℃,搅拌转速为800 r/min,搅拌时间为35 min。该工艺制备的铸锭经过热轧后,可获得表面光洁的A356-10%B 4C p复合板材。

In this paper,a semi-solid stirring and hot rolling process was used to prepare A356-10%B 4C p composite sheet,the effects of semi-solid stirring parameters on the as-cast and hot-rolled microstructures of the A356-10%B 4C p composites were studied.It is found that,when the mi-xing temperature is 580℃,the mixing time is 15 min,stirring speed is within 800 r/min,the average diameter and roundness ofα-Al grains decrease with the increase of stirring speed,and the distribution of B 4C particles tends to be uniform.When the stirring speed exceeds 800 r/min,the average diameter and roundness ofα-Al did not decrease,and the distribution of B 4C particles tends to be nonuniform.When the mixing temperature is 580℃,stirring speed is 800 r/min,stirring time is within 5—35 min,the average diameter and roundness ofα-Al decreased with the increase of stirring time,and the distribution of B 4C particles was also uniform.The optimum technological parameters are as follows:stirring temperature is 580℃,stirring speed is 800 r/min,stirring time is 35 min.The A356-10%B 4C p composite plate with smooth surface can be obtained after hot rolling of the composite ingot prepared by the process.