放电等离子烧结快速制备高钪含量铝钪合金

采用放电等离子烧结技术制备高钪含量Al-Sc合金,利用扫描电子显微镜、能谱仪和X射线衍射仪等设备对球磨前后Al-Sc合金粉末的形貌、相组成以及不同温度快速烧结样品的显微组织结构进行观察和分析,研究烧结温度对Al-Sc合金显微组织的影响。结果表明:球磨后粉末的形状较规则,其颗粒尺寸为25~45mm,并初步实现了机械合金化,除Al、Sc相以外,有少量Al3Sc和AlSc2相生成。放电等离子烧结可实现高钪含量铝钪合金的快速致密化,成功制备出钪含量30%(质量分数)的铝钪合金,通过调整烧结工艺参数,烧结样品的相对密度可达92.19%;当烧结温度高于500℃时,所得样品致密,无孔洞,且无明显晶界;随着烧结温度的提高,Sc相与第二相融合,形成Al3Sc、AlSc2等第二相,存在于合金中,且Al3Sc相呈现逐渐增强的趋势。

Superfast preparation of Al-Sc alloys with high Sc content by spark plasma sintering

Aluminum-scandium alloys with high scandium content by mass were prepared by spark plasma sintering (SPS). The morphology, the phase composition, and the microstructures after sintering at different temperatures of Al-Sc alloy powders were investigated by scanning electron microscope (SEM), energy dispersive spectrometry (EDS), and X-ray diffractometry (XRD). The effect of sintering temperature on the microstructure of Al-Sc alloys was studied in the paper. The results show that, the Al-Sc alloy powders after ball milling are regular with the particle size of 25~45 μm, and the mechanical alloying of Al-Sc alloy powders is realized initially. In addition to the Al and Sc phases, a small amount of Al₃Sc and AlSc₂ are generated. The spark plasma sintering can realize the rapid densification of Al-Sc alloy with high scandium content, the Al-Sc alloy with 30% Sc by mass is successfully produced by SPS method. By adjusting the SPS process parameters, the relative density of sintered sample can be improved to 92.19%. The samples with the higher density and non-obvious grain boundary are achieved at the sintered temperature above 500℃. The second phases of Al₃Sc and AlSc₂ are formed by the combination of Sc with the increase of sintering temperature, and the peak intensity of Al₃Sc increases gradually.