深冷处理对ZA27合金组织性能的影响

对铸态ZA27合金进行350 ℃×2 h的固溶处理后分别水冷和深冷处理。通过测量硬度、磨损试验以及XRD、金相观察, 对水冷和不同深冷时间下锌合金组织和性能做了对比分析。结果表明, 固溶后直接深冷处理4 h的锌合金硬度最高; XRD结果表明深冷处理后合金某些相的衍射峰相对强度发生了变化; 通过显微组织观察发现固溶深冷4 h的合金中共析组织片层结构增多, 且细小均匀; 深冷后耐磨性也得到提高, 且低转速下效果更加明显。

Effects of Deep Cryogenic Treatment on Microstructures and Property of ZA27

After solution treatment at 350 ℃ for 2 hours, as-cast ZA27 alloys were cooled in water and liquid nitrogen respectively．The properties and microstructures of zinc alloy at different water and liquid nitrogen temperatures were analyzed comparatively by microhardness measurement, X-ray diffraction, optical microscope and metallographic observation. It is showed that the zinc alloy has the highest hardness after solution directly by deep cryogenic treatment for 4 hours. And the XRD results also showed that there were some changes in the diffraction peaks of some alloy phases after cryogenic treatment. It was found through microstructure observation that solution-deep cryogenic treatment for 4 hours resulted in the increasing of fine and uniform lamellar eutectic structure in the alloy. The cryogenic treatment also improved the wearability of alloy, especially at a low rotating speed.