利用超重力分离5052铝合金熔体中的非金属夹杂

Application of super gravity to separating non-metallic inclusions from 5052 aluminum alloy melt

  • 摘要: 在自行设计改装的超重力装置上采用超重力场分离铝熔体中的非金属夹杂,研究了不同重力系数下,5052铝合金熔体中夹杂物的分离规律.实验结果表明:经过超重力处理后,非金属夹杂沉降聚集至试样底部,且随着重力系数的增大,夹杂在试样底部聚集程度越好.试样处理5 min后,常重力条件下,夹杂物在试样底部的沉降比率为0.35;当重力系数G=250时,夹杂物在试样底部的沉降比率达到0.99.根据Stokes定律,超重力场中固相颗粒能够瞬间达到临界沉降速度,当重力系数G=1时,νr=7.25×10-5 m/s,而当G=250时,νr=1.813×10-2 m/s,这意味着,随着重力系数的增加,熔体中固相颗粒的临界速度指数递增.这表明超重力法可以有效分离金属熔体中的非金属夹杂.

     

    Abstract: Super-gravity segregation performed on self-designed centrifugal furnace is applied to separate non-metallic inclusions in molten aluminum under various gravity fields. The results show that the oxide inclusions are accumulated to the bottom of samples by super-gravity treatment. The level of inclusions aggregation became more remarkable with the increasing of super-gravity field. The settling rate of inclusions at the bottom of the sample is 0.35 after 5 minutes treatment under conventional gravity, while the settling rate of inclusions is 0.99 under super-gravity with G=250. According to the Stokes' law, the terminal velocity reaches at a very early stage of the process (when G=1, νr is 7.25×10-5 m/s). However, when G=250 m/s, νr reaches 1.813×10-2 m/s, which indicates the terminal velocity increases exponentially with adding gravity coefficient. Hence, the non-metallic inclusions can be separated effectively under super-gravity fields.

     

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