(山東大學(xué) 材料液固結(jié)構(gòu)演變與加工教育部重點(diǎn)實(shí)驗(yàn)室，濟(jì)南 250061)
摘 要: 采用宏觀硬度、力學(xué)拉伸、室溫及高溫摩擦磨損、掃描電鏡等測(cè)試分析方法，研究Al-Si合金經(jīng)不同變質(zhì)處理使Si相形貌不同時(shí)，各項(xiàng)力學(xué)性能的變化情況。結(jié)果表明：近共晶Al-13Si合金經(jīng)Sr變質(zhì)處理后拉伸性能優(yōu)于P變質(zhì)處理，拉伸強(qiáng)度相比提高23%，室溫耐磨性也較P變質(zhì)的好；但高溫耐磨性相反，P變質(zhì)處理后合金高溫摩擦因數(shù)曲線變化更加平穩(wěn)；兩種變質(zhì)處理后合金硬度值均在62~65HBW之間，表明硬度對(duì)Si相形貌變化不敏感。過(guò)共晶Al-25Si合金經(jīng)Al-P合金細(xì)化處理后，拉伸強(qiáng)度提高53%；室溫磨損量降低，尤其是高載荷條件下，高溫摩擦因數(shù)曲線變化更穩(wěn)定，室溫和高溫耐磨性均得到明顯改善；但硬度值仍保持在77HBW左右不變。
關(guān)鍵字: Al-Si合金；變質(zhì)處理；Si相形貌；力學(xué)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
