鋳造用Al-Cu合金の機械的性質並びに流動性に及ぼすけい素，マグネシウム及び亜鉛の影響

抄録

  The influences of Si, Mg and Zn on the mechanical properties and fluidity of Al-4.5%Cu alloy was investigated. The cast alloys were solution heat-treated at 515°C for 10 hrs and tempered 160 °C for 8 hrs.
  The addition of Si to Al-4.5%Cu-0.25%Ti alloy lowered the tensile strength somewhat and increased elongation. The addition of Mg to Al-4.5%Cu-0.25%Ti alloy made the tensile strength higher and the elongation smaller than those of Al-4.5%Cu-1.0%Si-0.25%Ti alloy. The addition of both Si and Mg to the Al-4.5Cu-0.25%Ti alloy made the tensile strength higher and the elongation smaller than those of Al-4.5%Cu-0.3%Mg-0.25%Ti alloy. The addition of 1-3%Zn to Al-Cu-Si-Ti alloys improved the tensile strength remarkably. However, these alloys containing 4%Zn were susceptible to burning so that the solution heat treatment temperatures had to be lowered.
  It was found in these alloys that the more the silicon was added, the more the shrinkage cavity in the feeder decreased, and titanium reduced the contraction of the feeder remarkably, The length of fluidity was extended more in Al-Cu alloys with silicon or magnesium addition. When a small amount of titanium was added to Al-Cu-Si, Al-Cu-Mg and Al-Cu-Mg alloys, the sensibility to temperature on the fluidity became smaller and the fluidity of those alloys became better.