摘要
研究了两种不同凝固特性的铝合金在局部加压条件下的宏观组织与成分偏析。结果表明:加压使加压杆周围的组织细化,糊状凝固特性的AC4B合金中等轴晶晶粒比层状凝固的ADC12细小。铜的成分分析显示AC4B合金易在加压杆下方形成负偏析;且离加压杆端面越近,偏析程度越大。ADC12合金仅在加压杆圆柱面下方5mm处有轻微的负偏析,其偏析程度不受加压开始时间的影响。与形成的负偏析相对应,在加压杆圆柱面周围则形成了正偏析。
In this investigation, a study for local pressurization was carried out with a specially designed permanent mold to examine macrostructure and segregation for two kinds of Al alloys with different solidification modes. The results showed that grain was refined by pressurization. Copper content analyzed by ICP illustrate that segregation under the pin tip is negative one and easily occurred for AC4B rather than for ADC12 alloy. The degree of segregation differs with position from the pin tip in the casting for AC4B. Negative segregation in ADC12 only occurred in annular position about 5mm below the pin tip and did not affected by pressurization starting time. On the contrary, there appears positive segregation of copper in the upper zone around pin.
出处
《铸造》
CAS
CSCD
北大核心
2004年第4期266-270,共5页
Foundry
关键词
局部加压
压铸
铝合金
宏观组织
成分偏析
local pressurization
die casting
Al alloy
macrostructure
segregation
