【摘要】 采用快速凝固技术制备Mg-5Zn-1Y-0.6Zr合金,用XRD、SEM、HRTEM、显微硬度测量等分析方法研究其凝固组织和性能。结果表明,合金由α-Mg固溶体、晶界处不连续分布的I(Mg3Zn6Y)准晶相和非晶相组成。根据热传导理论,采用一维傅立叶热传导方程计算了合金的冷却速度。冷却速度的提高使得晶粒细化、成分均匀、非晶相含量增多。硬度(HV)随冷速的提高显著增大,最大值为167.23,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 rapidly solidified method.Solidification structure and properties of the prepared alloy were investigated by XRD,SEM,HRTEM and micro-hardness measurements.Microstructure of the alloy is composed of fine α-Mg phase,amorphous phases and I-Mg3Zn6Y quasicrystal phase discontinuously distributes along crystal boundary.Based on the heat transfer theory,the cooling rate of the alloy ribbons can be calculated by one-dimensional heat conductivity equation.With the increase of cooling rate,grain size in the microstructure of the alloy is refined with the more homogeneous distribution of composition,and the volumetric fractions of amorphous phase are raised,meanwhile,micro-hardness value of the alloy is increased greatly,and the maximum value reaches Hv 167,which is 2.2 times of that of the conventionally solidified alloy.更多还原