| Autor: |
Wen MC; Institute of Material Science and Engineering, National Central University, Taoyuan 320, Taiwan., Hsu YD; Department of Mechanical Engineering, National Central University, Taoyuan 320, Taiwan., Chen MC; Institute of Material Science and Engineering, National Central University, Taoyuan 320, Taiwan., Yang WC; Institute of Material Science and Engineering, National Central University, Taoyuan 320, Taiwan., Lee SL; Institute of Material Science and Engineering, National Central University, Taoyuan 320, Taiwan. |
| Abstrakt: |
This study investigated the effects of a minor Zr addition (0.15 wt%) and heterogenization treatment (one-stage/two-stage) on the hot-working temperature and mechanical properties in Al-4.9Cu-1.2Mg-0.9Mn alloy. The results indicated that the eutectic phases (α-Al + θ-Al 2 Cu + S-Al 2 CuMg) dissolved after heterogenization, retaining θ-Al 2 Cu and τ 1 -Al 29 Cu 4 Mn 6 phases, while the onset melting temperature increased to approximately 17 °C. A change in the onset melting temperature and evolution of the microstructure is used to assess an improvement in hot-working behavior. With the minor Zr addition, the alloy exhibited enhanced mechanical properties due to grain growth inhibition. Zr-added alloys show 490 ± 3 MPa ultimate tensile strength and 77.5 ± 0.7 HRB hardness after T4 tempering, compared to 460 ± 2.2 MPa and 73.7 ± 0.4 HRB for un-added alloys. Additionally, combining minor Zr addition and two-stage heterogenization resulted in finer Al 3 Zr dispersoids. Two-stage heterogenized alloys had an average Al 3 Zr size of 15 ± 5 nm, while one-stage heterogenized alloys had an average size of 25 ± 8 nm. A partial decrease in the mechanical properties of the Zr-free alloy was observed after two-stage heterogenization. The one-stage heterogenized alloy had 75.4 ± 0.4 HRB hardness after being T4-tempered, whereas the two-stage heterogenized alloy had 73.7 ± 0.4 HRB hardness after being T4-tempered. |
