对不同 Mn 含量的 Al-Mn 二元合金进行螺旋形流动性试样长度的测试，并通过计 算机辅助冷却曲线热分析技术研究该二元合金的凝固特性，以分析流动性变化的内在机 制． 结果表明:当 Mn 含量(质量分数)从 0. 6%增至 2. 7%时，合金流动性呈先升高后降低 的趋势;当 Mn 含量为 2. 0% 时，该二元合金的流动性最佳，其流动长度达到商用 ADC12 铝合金的 88. 5%． 热分析结果表明，合金凝固区间和浇注温度/枝晶搭接温度之差随 Mn 含量的变化而呈现一定规律，其趋势和流动长度变化趋势相一致．

In the investigation,the fluidity of the Al-Mn alloy of different Mn contents is tested by a spiral perma- nent mould.Then,the solidification characteristic of the alloy is measured through the computer-aided cooling curve thermal analysis so as to reveal the inherent mechanism of the fluidity change.The results show that,when the Mn dosage increases from 0. 6% (mass fraction) to 2. 7%,the fluidity of the Al-Mn alloy tends to increase first and then decrease,and that the Al-Mn alloy is of the best fluidity when the Mn dosage is 2. 0% and the fluidity length reaches up to 88. 5% of commercial ADC12 alloy.Thermal analysis results show that there exist some laws in the changes of both the alloy solidification range and the difference between the pouring temperature and the den- drite coherency temperature with the Mn dosage,and the corresponding trend accords well with the change trend of the fluidity length.