(華東交通大學 機電工程學院 載運工具與裝備教育部重點實驗室，南昌 330013)
摘 要: 采用間接超聲振動輔助鑄造法制備Al-24%Si合金(質(zhì)量分數(shù))，利用金相顯微鏡、電子萬能試驗機、磨損試驗機、掃描電鏡和顯微硬度計分別研究超聲波頻率對合金的顯微組織、抗壓強度、磨損性能和顯微硬度的影響。結(jié)果表明:施加20.4 kHz的超聲處理對合金中初晶硅和共晶硅的細化作用最佳，初晶硅平均尺寸為100 μm，共晶硅平均尺寸為40 μm；隨著超聲頻率的增大，合金抗壓強度先增大后減小，磨損率先減小后增大；磨損機制主要為磨粒磨損和粘著磨損；合金的顯微硬度先增大后減小，與合金中硅相尺寸呈負相關(guān)關(guān)系。
關(guān)鍵字: Al-24%Si合金；顯微組織；超聲頻率；抗壓強度；磨損性能；顯微硬度
（Key Laboratory of Ministry of Education for Conveyance and Equipment,
School of Mechatronics Engineering, East China Jiaotong University, Nanchang 330013, China）
Abstract:Al-24%Si alloy was prepared by indirect ultrasonic aided casting method. With metalloscope, vertical electronic universal testing machine, abrasion tester, scanning electron microscope and microhardness tester, the influences of ultrasonic frequency on the microstructure, compressive strength, wear performance and hardness of the alloy were investigated. The results show that 20.4 kHz ultrasonication has the best refining effect on the alloy primary silicon and eutectic silicon with average sizes are 100 and 40 μm, respectively. Along with the increase of ultrasonic frequency, the compressive strength increases first and then decreases, while the wear rate decreases first and then increases. Furthermore, the wear mechanism of the alloy is mainly represented as abrasive wear and adhesive wear. Additionally, the alloy microhardness increases first and then decreases along with the increase of ultrasonic frequency, and has a negative correlation with grain size of silicon in the alloy.
Key words: Al-24%Si alloy; microstructure; ultrasonic frequency; compressive strength; wear property; microhardness
