Al-Li系鋳物合金の鋳造性に及ぼすジルコンおよびチタン添加の影響 Effects of Zr and Ti Contents on Castability of Al-Li-Cu-Mg and Al-Li-Mg Alloys
Castability of Al-Li-Cu-Mg and Al-Li-Mg alloys containing small amount of Zr and / or Ti were investigated using a spiral mold for fluidity test, ring mold for tearing test and feeder of the stepped form metal mold for contraction behavior test. The fluidity of the Al-2.5%Li-2%Mg alloy was lower than that of the Al-2%Mg alloy due to the fine <i>α</i>-Al dendrites, but the fluidity of the Al-2.5%Li-1.2%Cu-0.7%Mg alloy was higher than the Al-1.2%Cu-0.7%Mg alloy due to the occuring multiple eutectic reaction at 823K. When Zr and / or Ti contents in Al-2.5%Li-1.2%Cu-0.7%Mg and Al-2.5% Li-2% Mg alloys were above 0.25%, fluidity dropped and their fluidity length were 70-85% of the length of A356 (Al-7%Si-0.3%Mg). Hot tearing length decreased with the addition of Zr and Ti due to the increased strength of the solidified matrix alloy by grain refinement and low temperature at the beginning of solidification contraction. External contraction in the feeder of stepped castings increased, but the internal contraction decreased according as the Zr and / or Ti content increased, because of the retardation of the formation of outer solidified <i>α</i>-Al dendrites shell in contact with the mold surface.
- 鋳造工学 = Journal of Japan Foundry Engineering Society
鋳造工学 = Journal of Japan Foundry Engineering Society 69(6), 469-476, 1997-06