热分析技术检测319铝合金熔体质量的研究

Quality Detection of 319 Al Alloy Melt by Thermal Analysis

运用热分析技术研究了冷却曲线特征值与319铝合金铸件气孔率及变质剂Sr的加入量之间的关系。结果表明,TEAl,Smiin与TAEl,Cmuin的温度差ΔT与铸件气孔率P之间有显著的关系,随气孔率P的增大,ΔT呈上升趋势,其关系可表示为P=45.0+0.417×ΔT。319铝合金中变质剂Sr的加入量达到0.008%时,合金充分变质,Sr的加入量超过0.030%时,变质效果变差,Sr的加入量大于0.008%时,Sr的加入量与TAEl,Smiin的关系可以表示为:TEAl,Smiin=543.2+375.5×wSr-5399.3×wS2r。

The relationships between characteristic value of cooling curve and the porosity of 319 Al alloy as well as the content of modifier Sr have been detected by thermal analysis. The results show that the temperature difference is closely related to the porosity in castings. With increasing in porosity,the temperature difference is increased. The alloy can be totally modified with 0.008% Sr addition while the modification effects can be deteriorated with the Sr addition more than 0.03%.