The Research On The High Aluminum Zinc Based Alloy Intensified By Rare Earth Oxide

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.