【摘要】 采用普通凝固和快速凝固技术制备Mg-5Zn-1Y-0.6Zr合金,用XRD,SEM,显微硬度测量等分析方法研究其凝固组织和性能特征。结果表明,普通凝固合金由α-Mg固溶体和在晶界处呈不连续网状分布的三元相I-(Mg3Zn6Y)准晶相和W-(Mg3Zn3Y2)相组成。快速凝固合金晶粒细化并产生非晶相,晶间化合物全部转化为准晶I相。非晶相的出现及显微组织细化是造成快速凝固合金条带显微硬度提高的主要原因。快速凝固合金条带的显微硬度随冷速提高显著增大,最大值HV167.23是普通凝固合金的2.2倍。更多还原

【Abstract】 The Mg-5Zn-1Y-0.6Zr alloys were prepared by conventionally solidified method and rapidly solidified method.The solidification microstructures and properties of the alloys were observed by XRD,SEM and micro-hardness measurements.The results indicate that the conventionally solidified alloy is composed of preliminary α-Mg matrix and interdendritic ternary phases of I-(Mg3Zn6Y) quasicrystal phase and W-(Mg3Zn3Y2) phase in the grain boundary.The rapidly solidified alloys are composed of fine α-Mg matrix phase,amorphous phase and quasicrystal I-phase.The amorphous phase and ultra-fine phase are the main reason to increase the micro-hardness value of the alloy ribbon.With the increase of cooling rate,the micro-hardness of the rapidly solidified alloys increase tremendously.The maximum micro-hardness value of the rapidly solidified alloy is HV167.23,which is 2.2 times the size of the conventionally solidified alloy.更多还原