摘要
研究了La含量(4%、6%、8%、10%)对压铸Al-La合金的微观组织、力学性能以及导电导热性能的影响。La在铝基体中的固溶度极小,易富集于α-Al凝固界面前沿而造成成分过冷,降低α-Al周围液相的结晶温度,进而抑制α-Al的生长而实现细化。凝固过程中生成的Al11La3第二相不仅可以强化合金,还可作为α-Al的异质形核点以实现细化,这得益于其与α-Al基体5.96%的较小错配度。随着La含量从4%增加到10%,合金的屈服强度与抗拉强度分别从48.6MPa、113.9MPa提升到92.3MPa、186.7MPa,但伸长率从26.1%降低至9.6%。此外,Al-La合金的热导率、电导率随La含量的增加大致呈线性下降趋势,分别从207.8 W/(m·K)、32.0 MS/m下降至173.1 W/(m·K)、26.1 MS/m。
The effects of La contents(4%,6%,8%,10%)on the microstructures,mechanical properties,thermal and electrical conductivities of die-cast Al-La alloys were investigated.The solid solubility of lanthanum in aluminum matrix was very small,and it was easy to enrich in the front of the solidification interface ofα-Al,resulting in component supercooling,reducing the crystallization temperature of the liquid aroundα-Al,and then inhibiting the growth ofα-Al to achieve refinement.The secondary phase Al11La3 produced during solidification process not only improved the strength of the alloy,but also could be used as heterogeneous nucleation point ofα-Al to achieve refinement,which was benefit from the small lattice mismatch of 5.96%.With the increase of La content from 4%to 10%,the yield strength and ultimate tensile strength of the alloy increased from 48.6 MPa and 113.9 MPa to 92.3 MPa and 186.7 MPa,respectively,but the elongation decreased from 26.1%to 9.6%.In addition.It was found that the thermal and electrical conductivities decreased linearly with the increase of La content,from 207.8 W/(m·K),32.0 MS/m to 173.1 W/(m·K),26.1 MS/m,respectively.
作者
裘珂可
周其良
郭潘狄
彭暄霖
胡波
李德江
曾小勤
QIU Ke-ke;ZHOU Qi-iang;GUO Pan-di;PENG Xuan-in;HU Bo;LI De-jiang;ZENG Xiao-qin(Zhejiang Jufeng Technology Co.,Ltd.,Shengzhou 312400,Zhejiang,China;School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)
出处
《铸造》
CAS
2024年第7期947-954,共8页
Foundry
基金
绍兴市科技计划项目(2022B41020)。
关键词
Al-La合金
第二相
力学性能
电导率
热导率
Al-La alloy
secondary phase
mechanical properties
electrical conductivity
thermal conductivity
