Abstract The influence of Sc microalloying on compressive creep behaviors of Al-0.2Zr and Al-0.2Zr-0.1Sc alloy have been studied. The steady state creep rate of Al-0.2Zr-0.1Sc alloy ranged from 1.124 × 10−9 s−1 to 1.926 × 10−8 s−1 at 90–150 °C /70 MPa. By contrast, the steady state creep rate of Al-0.2Zr alloy ranged from 6.862 × 10−8 s−1 to 8.560 × 10−7 s−1, indicating that Sc addition significantly improve the compressive creep resistance of Al-0.2Zr alloy. According to the TEM micrographs, except for Al3(Zr,Sc) precipitates precipitated during aging, a large number of fine dispersed Al3Sc precipitates precipitated after creep for 70 h, which significantly hinder movements of dislocations and grain boundaries. As a result, the steady-state creep rate of Al-0.2Zr-0.1Sc alloy slightly decreases after 70 h at 150 °C /70 MPa. The critical creep stress value of Al-0.2Zr alloy is 47.2 MPa, and that of Al-0.2Zr-0.1Sc alloy is 68.4 MPa. The higher critical creep stress value indicates the more excellent compressive creep resistance.

中文翻译：

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含L12结构富Sc析出物的Al-0.2Zr合金抗压蠕变性能的提高

摘要 研究了Sc微合金化对Al-0.2Zr和Al-0.2Zr-0.1Sc合金压缩蠕变行为的影响。Al-0.2Zr-0.1Sc 合金的稳态蠕变速率范围为 1.124 × 10-9 s-1 至 1.926 × 10-8 s-1，温度为 90-150 °C /70 MPa。相比之下，Al-0.2Zr合金的稳态蠕变速率范围从6.862×10-8 s-1到8.560×10-7 s-1，表明Sc的加入显着提高了Al-0.2Zr合金的抗压蠕变能力. 根据TEM显微照片，除了时效过程中析出的Al3(Zr,Sc)析出物外，蠕变70 h后析出大量细小分散的Al3Sc析出物，显着阻碍了位错和晶界的运动。因此，Al-0.2Zr-0.1Sc 合金的稳态蠕变速率在 150 °C /70 MPa 下 70 小时后略有下降。Al-0.2Zr合金的临界蠕变应力值为47.2 MPa，Al-0.2Zr-0.1Sc合金的临界蠕变应力值为68.4 MPa。临界蠕变应力值越高表明抗压蠕变性能越优异。