论文部分内容阅读
研究了两种不同凝固特性的Al Si Cu合金在局部加压方式下Cu的偏析现象。结果表明 :糊状凝固特性的合金AC4B易在加压杆下方形成Cu的负偏析 ,偏析程度受加压开始时间的影响 ;层状凝固特性的ADC12仅在加压杆圆柱面下方5mm处有轻微的负偏析 ,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。偏析的生成是因为局部加压使枝晶间的浓缩液体产生局部流动而形成的
The segregation behavior of Cu in two different solidification properties of Al Si Cu alloy under local pressurization was investigated. The results show that AC4B with paste-like solidification tends to form negative segregation of Cu under the pressure bar, and the degree of segregation is affected by the pressure start time. The ADC12 with lamellar solidification characteristics is only slightly 5mm below the cylindrical surface of the pressure bar Negative segregation, the degree of segregation is not affected by the start of the pressure. Corresponding to the negative segregation formed, positive segregation is formed around the cylindrical surface of the pressing rod. The formation of segregation is caused by the localized pressurization of localized flow of the concentrated liquid between the dendrites