【摘要】 在脉冲磁场下,以Al-ZrSiO4为反应体系成功制备了内生Al3Zr和Al2O3颗粒增强铝基复合材料。用X射线衍射仪(XRD)、扫描电镜(SEM)、电子探针(EPMA)等研究了(Al2O3+Al3Zr)p/Al复合材料的相组成、凝固组织和内生增强体的特征。试验结果表明,在脉冲磁场作用下,原位合成的颗粒细小,呈矩形或短棒状的Al3Zr颗粒尺寸为1~3!m,形状圆整的Al2O3颗粒尺寸小于2"m,且弥散分布于基体中。随着外加脉冲磁场强度的增大,反应生成的增强颗粒变得更加细小,分布更均匀。外加脉冲磁场作用时间短,颗粒体积分数低,颗粒粗大;作用时间长,颗粒体积分数明显下降,部分颗粒开始团聚长大,最佳的作用时间为15~20min。更多还原

【Abstract】 In-situ Al3Zr and Al2O3 particles reinforced aluminum matrix composites have been synthesized successfully under pulsed magnetic field in the system Al-ZrSiO4. The phase composition, solidification microstructure and in-situ particulate features of(Al2O3+Al3Zr)p/Al composites have been investigated using X-ray diffraction(XRD), scanning electron microscope(SEM), electron probe micro-analyzer(EPMA)and other modern equipment. It is found that in-situ formed particles synthesized under pulsed magnetic field are finer and well distributed in the Al matrix than that under zero magnetic field. The size of Al3Zr particles in the shape of rectangle or short bar is in the range of 1-3 цm and Al2O3 particles in the shape of circularity is less than 2 цm. With the increasing of the plused magnetic intensity, the size and distribution of in-situ particles in the matrix become refiner and more homogenous. And when the melt exposed to the pulsed magnetic field in a short time, the volume fraction of the particles in the microstructure is lower and the size of the particles is thicker, however, with the increasing of the applying time of pulsed magnetic field, the volume fraction of in-situ particles in the melt decreases obviously, while the part of in-situ formed particles starts to aggregate and grow up, so the optimum time is 15-20 min.更多还原