【摘要】 分析了经过RE、Ti变质ZA27合金的非平衡凝固过程,获得的合金铸态组织是由枝晶α相、枝晶边缘的β相以及呈网状分布的晶界共晶体组成。这种能降低材料塑韧性的网状组织用固溶淬火处理可以消除,进而提高合金的塑韧性。利用投射电镜对合金铸态组织的微观结构进行了研究,发现在枝晶心部存在着调幅分解产物———"类织物",并说明了类织物的生成过程。此外,研究了RE、Ti使合金组织细化的变质机理。更多还原

【Abstract】 It is analyzed that the process of un-equilibrium solidification of Z A27 alloy modified by adding RE and Ti.The as-cast structure of ZA27 alloy is m ade up of dendrite α phase,β phase and ternary eutectic which is net structure reducing the plasticity- toughness pro perties.Ternary eutectic can be eliminated by quenching, and the plasticity- t oughness capacity of ZA27 alloy is improved.By observing the as-cast microstruc ture of ZA27 alloy by TEM,the spinodal transformation is occurred in the center of dendrite and then form the tweed-like microstructure,meanwhile the growth pr ocess of which is showed.The modification mechanism that the addition of Ti and Re to the ZA27 alloy can refine microstructure is studied.更多还原