【作者】 闫承俊；

【导师】 王吉岱；

【作者基本信息】 山东科技大学 ， 材料学， 2006， 硕士

【摘要】 锌铝合金制造成本低，具有良好的使用和加工性能，显示出较好的应用前景与经济优势。然而，合金的高温性能差，易发生蠕变等缺点，限制了合金的进一步推广应用。为此，本文试图探索改善锌铝合金的组织与性能的新方法、新途径。通过添加稀土氧化物及提高锌基合金中铝的含量，制备高铝锌基复合材料，来提高合金的室温及高温力学性能，改善其摩擦磨损性能。 本文评述了锌铝合金的发展概况和研究现状，研究了稀土氧化物强化的高铝锌基合金的金相组织、力学性能(包括强度、硬度、延伸率及高温强度)及摩擦磨损性能。结果表明，高铝锌基合金的组织为富铝α相枝晶和α与η相的共析体及少量富铜ε相、共晶体。随着合金中含铝量的增加，α相枝晶增多，而共析体减少。高铝锌基合金中添加了稀土氧化物后，合金的室温及高温力学性能均得到提高。室温抗拉强度比ZA40基体提高了12.4％，硬度提高24.5％，高温抗拉强度提高了43％，但延伸率有所下降。摩擦磨损性能与ZA27及铸造铅青铜ZQPbD相比也得到提高。 稀土氧化物及锶盐的加入使基体组织，尤其是初晶Si及初生树枝晶α相得到细化，弥散分布的氧化物颗粒起到第二相强化作用。但由于氧化物颗粒的粒度达到微米级，加入过多的稀土氧化物会发生团聚，反而使材料的力学性能恶化。更多还原

【Abstract】 Zinc Aluminium alloys show a preferable application foreground and economic predominance in engineering because of low cost and favorable using and machining properties.But their applications have been limited because of poor high temperature mechanical properties and corrosion resistance . Therefore,the purpose of this research is to find new methods and new approaches to improve the microstructure and properties of ZA alloys.By adding rare earth oxide to make ZA alloys composites , increasing the aluminum content of zinc based alloys , which can improve room temperature and high temperature mechanical properties of ZA alloys, amend friction and abrasion properties of ZA alloys.In this paper, the development general situation and research status of Zn-Al alloys have been reviewed. The paper has studied the high Al Zn-based alloys reinforced by rare earth oxide, observed and investigated the metallographic microstucture and mechanical properties (include strength, hardness, ductility and tensile strength at high temperature) and friction abrasion properties. The result demonstrate that the high Al Zn-based alloys consisted of aluminium-rich α branch crystal、α and η eutectoid and a few copper-rich ε phase、 eutectic.With the increasing aluminium content of alloys, α phase is increased, but α and η eutectoid is drcreased. After adding rare earth oxide to the high Al Zn-based alloys, their room temperature and high temperature mechanical properties are improved.Compared with the ZA40 composites, its room temperature tensile strength improved 12.4%, hardness improved 24.5%, high temperature tensile strength improved 43% , but its ductility reduced. Compared with the ZA27 and cast plumbum-bronze ZQPbD, its friction and wear properties are increased.The rare earth oxide and strontium salt can refine the basic structure 、 firstborn Si phase and firstborn α branch crystal.The dispered oxide grains as the second phases reinforced the alloys. But as the oxide grains are very small , too much rare earth oxide can be reunited, so result in the decrease of mechanical properties of the composites.更多还原