超声对Al-14Si-xFe-yMn合金富Fe相和性能的影响

Influence of Ultrasonic Vibration Treatment on Fe-enriched Phases and Mechanical Properties of Al-14Si-xFe-yMn Alloys

研究了超声处理对Al-14Si-xFe-yMn(x=1,2,3,4,y/x=0.2)合金中富Fe相和力学性能的影响。结果表明,无超声处理时,Al-14Si-1Fe-0.2Mn合金组织中含大量针状β-Al_5FeSi相。当Fe含量达到或超过2%时,板条状δ-Al_4FeSi_2相出现。超声处理不仅使得粗大β-Al_5FeSi和δ-Al_4FeSi_2相细化,还促进了不规则多边形α-Al_(15)(Fe,Mn)_3Si_2相的生成。α相在超声处理结束后发生了Ostwald熟化,即随着Fe含量的增加,α相向着粗大近球形演变。在同等条件下,相比无超声处理的试样,有超声处理的试样室温强度显著提高。超声处理后合金的高温强度也略有增加。

The influence of ultrasonic vibration treatment （UVT） on the Fe-enriched phases and mechanical properties of Al-14Si-xFe-yMn （x=1,2,3,4, y/x=0.2） alloys were investigated. The results show that the long-needle-like β-Al5FeSi phase can be generated in the Al-14Si-1Fe-0.2Mn alloy without UVT. When the iron content in the alloy is equal or greater than 2%, both of the long-needle like β-Al5FeSi phase and coarse plate-like δ-Al4FeSi2 phase appear. The coarse β-Al5FeSi and δ-Al4FeSi2 phase can be refined to a certain extent after UVT. In addition, the formation of irregular polygonal α-Al15（Fe,Mn）3Si2 phase is also promoted. Ostwald ripening of the α-Al15 （Fe,Mn）3Si2 phase takes place during the solidification process after UVT. Some grains of α-Al15（Fe,Mn）3Si2 phase are close to spherical particles when the iron content is increased. The room temperature tensile strength of the alloy with UVT is improved significantly compared to that without UVT. The tensile strength at 350℃ is also improved slightly.