论文部分内容阅读
The Fe-rich intermetallic compounds in Al17Si-2Fe were modified via Al-Mn-Ti quasicrystal master alloy.The effect of master alloy content on the Fe-rich phase morphology was studied by scanning electron microscope (SEM) and thermodynamic calculation.Results show that the microstructure of the Al-Mn-Ti master alloy consists of binary quasicrystal matrix and ternary AlMnTi secondary phase.The evolutive tendency of Fe-rich intermetallic compounds with content of quasicrystal Al-Mn-Ti master alloy increasing can be described as follows: long needle-shaped β phase for Al-17Si-2Fe alloy,long plate-shaped ternary δ phase for 3 wt％ master alloy addition,Chinese-script and polyhedral α phases for 4 wt％ master alloy addition and finer plate-shaped quaternary δ phase with α phases for 5 wt％ master alloy addition.The ultimate tensile strength of the Al-17Si-2Fe alloy with 4 wt％ master alloy addition (a mass ratio of wMn/wFe ≈ 0.7) increases by 23.8％ and the friction coefficient decreases from 0.45 to 0.35 compared with those of Mnfree alloy,α-Fe phases have less negative effect on the matrix compared with the long needle-shaped β phase and the plate-shaped 5 phase.