中文摘要：

采用常规铸造和分段式倾斜板过流冷却铸造工艺制备A1-22Si-2Fe-xMn合金，研究表明：过流冷却制备工艺能够改善初生si形貌及尺寸，但对针状富Fe相作用有限．利用扫描电镜、X射线衍射及透射电镜等手段分析过流冷却条件下Mn元素添加对富Fe相晶体结构的影响，通过摩擦磨损实验研究不同Mn／Fe质量比的过共晶Al-si合金的硬度及耐磨损性能．结果表明：随着过流冷却铸造过共晶A1-Si合金中Mn／Fe质量比增加，合金中四方结构的长针状富Fe相逐渐减少直至基本消失，当Mn／Fe质量比为0．7时，富Fe相主要为六方结构的块状或鱼骨状α-A115（Fe，Mn），i2相，此时，合金耐磨性较未添加Mn元素时有所提升，磨损机制以磨料磨损方式为主。

英文摘要：

A1-22Si-2Fe-xMn alloys were prepared by conventional casting and a segment-based inclined cooling plates. It is shown that inclined cooling preparation technology can improve the morphology and size of primary Si, but has limited effect on the needle-shaped Fe-rich phase. The effect of Mn addition on the crystal structure of Fe-rich phase under the condition of inclined cooling was analyzed by scanning electron microscopy （SEM） , X-ray diffraction （XRD） and transmission electron microscopy （TEM）. The hardness and wear resistance of hypereutectic Al-Si alloys with different Mn/Fe mass ratios were also researched by friction and wear test. Results indicate that long needle-shaped Fe-rich phase of tetragonal structure decreases gradually and disappears basically in al- loys as the Mn/Fe mass ratio increases by inclined cooling casting hypereutectic A1-Si alloys. When the Mn/Fe mass ratio is 0. 7, Fe- rich phase is mainly hexagonal structure block-shaped or fishbone-shaped α-Alls （ Fe, Mn） 3 Si2 phase. By the time, the wear resist- ance is enhanced compared with no Mn element addition. The wear mechanism gives priority to abrasive wear manner.