【摘要】 采用重力铸造制备了A1-10Si-1.2Cu-x B（x=0,0.02,0.04,0.06,0.08,0.1；质量分数，下同）合金。通过金相显微镜（OM）、扫描电镜（SEM）、能谱分析（EDS）、万能试验机和涡流导电仪等手段，分析了B元素的含量对合金的微观组织、力学性能及导电导热性能的影响。结果表明：不同B含量的A1-10Si-1.2Cu-x B组织均由初生α-Al相、共晶硅与富铁相和Al₂Cu组成，添加0.02%～0.1%B元素后，α-Al二次枝晶臂间距先减小后增大，同时在组织中析出了多元过渡族（钛、钒、锆、铬）硼化物；加入量为0.06%时硼化物沉淀的面积分数达到最大；合金的抗拉强度、屈服强度、断后伸长率和导热率呈现先升高后降低的趋势，并在B含量达0.06%时最大，分别为264.23 MPa、163.8 MPa、5.55%、132.3 W/（m·K）。更多还原

【Abstract】 A1-10Si-1.2Cu-x B(x=0,0.02,0.04,0.06,0.08,0.1%)alloys were prepared by gravity casting.The effects of B element on the microstructure,mechanical properties,electrical and thermal conductivity of the alloy were analyzed by means of metallographic microscope(OM),scanning electron microscope(SEM),energy spectrum analysis (EDS),universal testing machine and eddy current conductivity meter.The results showed that the microstructures of Al-10Si-1.2Cu-x B were composed of primary α-Al phase,eutectic silicon and ironrich phase and Al2Cu.With the addition of 0.02%～0.1%B element(the same below),the secondary dendrite arm spacing of α-Al decreased first and then increased,and the multi-transition group(titanium,vanadium,zirconium,chromium)borides were precipitated in the microstructure.The area fraction of boride precipitation reached the maximum when the content of B was 0.06%.The tensile strength,yield strength,elongation and thermal conductivity of the alloy increased first and then decreased,and reached the maximum when the B content reached 0.06%,which were 264.23 MPa,163.8 MPa,5.55% and 132.3 W/(m·K),respectively.更多还原