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对半固态Al-17Si-xFe(x=2,3,4)的流变性能进行了研究。测出了Al-17Si-xFe在液相线以上100℃、50℃和液相线以下10℃和40℃的粘度,及连续冷却过程中的粘度-温度曲线,4种温度下Al-17Si-2Fe合金熔体的粘度分别为0.7451、0.7878、0.9224、1.0829Pa·s。当Fe含量从2%增加到4%时,Al-17Si-xFe的定温粘度增大。但Fe含量较高时,在液相线以下40℃随着保温时间的增加,Fe相的析出和沉降也较严重,会一定程度上减小熔体的表观粘度。随着剪切时间的增加,Al-17Si-xFe合金熔体在液相线以下40℃的表观粘度先减小后增大;在连续冷却的过程中,随着温度的连续降低,熔体的固相率逐渐增大,熔体的表观粘度随之增大,但增加比较缓慢;当温度降低到固相线附近的时候,Al-17Si-xFe熔体表观粘度会急剧增大。另外,在相同剪切速率下,达到相同的固相率时,冷却速度越快,熔体表观粘度就越大。
The rheological properties of semisolid Al-17Si-xFe (x = 2,3,4) were investigated. The viscosity of Al-17Si-xFe at 100 ℃, 100 ℃ and below 10 ℃ and 40 ℃ below liquidus and the viscosity-temperature curve of Al-17Si-xFe during continuous cooling were measured. The Al-17Si- 2Fe alloy melt viscosity of 0.7451, 0.7878, 0.9224, 1.0829Pa · s respectively. When the content of Fe increased from 2% to 4%, the viscosity of Al-17Si-xFe increased. However, when the content of Fe is higher, precipitation and deposition of Fe phase are more severe at 40 ℃ below the liquidus with the increase of holding time, which will reduce the apparent viscosity of the melt to a certain extent. With the increase of shear time, the apparent viscosity of Al-17Si-xFe alloy melt decreases first and then increases at 40 ℃ below the liquidus phase. During the continuous cooling process, as the temperature decreases continuously, the melt The apparent viscosity of the melt increases slowly, but increases slowly. When the temperature decreases to near the solidus, the apparent viscosity of Al-17Si-xFe melt increases sharply. In addition, at the same shear rate, to achieve the same solid fraction, the faster the cooling rate, the greater the apparent viscosity of the melt.