(山东大学 材料液固结构演变与加工教育部重点实验室，济南 250061)
摘 要: 采用宏观硬度、力学拉伸、室温及高温摩擦磨损、扫描电镜等测试分析方法，研究Al-Si合金经不同变质处理使Si相形貌不同时，各项力学性能的变化情况。结果表明：近共晶Al-13Si合金经Sr变质处理后拉伸性能优于P变质处理，拉伸强度相比提高23%，室温耐磨性也较P变质的好；但高温耐磨性相反，P变质处理后合金高温摩擦因数曲线变化更加平稳；两种变质处理后合金硬度值均在62~65HBW之间，表明硬度对Si相形貌变化不敏感。过共晶Al-25Si合金经Al-P合金细化处理后，拉伸强度提高53%；室温磨损量降低，尤其是高载荷条件下，高温摩擦因数曲线变化更稳定，室温和高温耐磨性均得到明显改善；但硬度值仍保持在77HBW左右不变。
关键字: Al-Si合金；变质处理；Si相形貌；力学性能
（Key Laboratory of Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Ji’nan 250061, China）
Abstract:The difference in sensitivity of mechanical behaviors to the Si phase morphologies of Al-Si alloys prepared by different modification treatments was investigated by macro hardness test, tensile test, wear test and scanning electron microscopy. The results show that both of the ultimate tensile strength (UTS) and wear resistance at room temperature for Al-13Si alloy with Sr modification are superior to those of P modification; while the performance of wear resistance at high temperature is just the reverse, the variation of friction coefficient is more stable with P modification; the hardness keeps in the range of 62-65HBW, which indicates hardness is insensitive to the change of Si phase morphologies. Besides, the UTS of Al-25Si alloy increases by 53% after being refined by Al-P master alloy; wear resistances at room and high temperature are improved obviously due to lower abrasion loss and more stable friction coefficient curve, respectively; but the hardness is still 77HBW.
Key words: Al-Si alloy; modification treatment; Si phase morphology; mechanical property
