半固态AlSi6Mg2铝合金的稳态流变性能

RHEOLOGICAL BEHAVIOR OF SEMI-SOLID AlSi6Mg2 ALUMINUM ALLOY AT STEADY STATE

利用Couette型同轴双桶流变仪研究了半固态AlSi6Mg2铝合金浆料的等温稳态流变性能.结果表明:半固态AlSi6Mg2合金的稳态表观粘度随着固相分数的增加而增加,并且当固相分数达到某-临界值后表观粘度迅速增加;半固态AlSi6Mg2合金稳态表观粘度随着剪切速率增大而减小,并且随着剪切速率增加,表观粘度急剧增加,所对应的临界固相分数也随着增加;半固态AlSi6Mg2合金稳态表观粘度与固相分数和剪切速率之间的模型方程为:ηa=78.6 exp(6.17 fs)γ-36.

The apparent viscosities of semi-solid AlSi6Mg2 alloy at steady state were investigated using a Couette type viscometer. The results show that the apparent viscosities of semi-solid AlSi6Mg2 alloy at steady state increase with increasing solid fraction, but decline with increasing shearing rate. When the solid fraction reaches a critical value, the apparent viscosities increase rapidly and with the increase in shearing rate, the critical fraction value becomes bigger. Based on the experimental results, an empirical equation that shows the effect of solid fraction and shearing rate on the apparent viscosities was built as the following, eta(a)=78.6 exp(6.17 f(s))((gamma)over dot-1.36).