力学性能的影响
(1. 东南大学 机械工程系, 南京 210018;
2. 江苏永益铸管股份有限公司, 靖江 214500)
摘 要: 考察了Al-1B中间合金对0.030%Sr变质的Al-11.6%Si-0.4%Mg合金组织和力学性能的影响。 发现Al-B中间合金在近共晶铸造Al-Si合金中具有优异的枝晶细化能力。 通过比较3种不同熔体处理条件下(未变质＋未枝晶细化处理、 0.030%Sr变质处理、 0.030%Sr+0.028%B联合熔体处理)合金铸态和T6状态下的力学性能并对断口形貌进行分析， 可以得出在近共晶铸造Al-Si合金中同时加入Sr, B进行枝晶细化和共晶Si变质联合处理是十分必要的。
关键字: 锶; 硼; 铝硅合金; 力学性能; 组织
（1. Department of Mechanical Engineering, Southeast University,
Nanjing 210018, China;
2. Jiangsu Yongyi Casting Pipe Joint-stock
Company Limited, Jinjiang 214500, China）
Abstract:The influence of addition of Al-1B master alloy on the microstructure and mechanical properties of Al-11.6%Si-0.4%Mg alloy modified with 0.030%Sr were discussed. It is found that the Al-B master alloy has a very strong power of refining dendrite in near-eutectic Al-Si casting alloys. The mechanical properties and the fractographs of the alloy as-cast and after T6 heat treatment by three different melt treatments (no modifying+no refining, 0.030%Sr modifying, 0.030%Sr modifying+0.028%B refining) were also compared. It is concluded that the combined melt treatment of Sr+B is very necessary and important to improve the mechanical properties of the near-eutectic Al-Si casting alloys, especially the ductility.
Key words: strontium; boron; Al-Si alloy; mechanical property; microstructure
