粉体粒径对SPS制备Zr基非晶合金的影响研究
Study on Effect of Particle Size on Zr-based Amorphous Alloys Prepared by SPS
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摘要: 在相同的烧结工艺条件下,采用放电等离子热压烧结法对三种不同粒径的Zr55Cu30Al10Ni5非晶合金粉末进行烧结,制备得到块体非晶合金试样。通过对致密度、硬度和压缩强度等性能的测试,分析了粉末粒径对非晶合金烧结试样的具体影响。结果显示:非晶合金烧结试样的致密度随粉末粒径的增大而下降。这是因为在烧结的前期预压阶段,粉末主要通过机械运动和颗粒重排实现致密化,粒径越小,颗粒堆积越紧密,致密化效果越好;施加脉冲电流后,与大粒径粉末相比,小粒径粉末的相对接触面积更大,热量传递更迅速,致密化效果更好;三种不同粒径粉末烧结试样的硬度为:粒径106~250 μm粉末烧结试样>粒径15~53 μm粉末烧结试样>粒径53~106 μm粉末烧结试样,非晶的部分晶化导致粒径106~250 μm粉末烧结试样的硬度显著升高;三种不同粒径粉末烧结试样的压缩强度为:粒径53~106 μm粉末烧结试样>粒径106~250 μm粉末烧结试样>粒径15~53 μm粉末烧结试样,小粒径粉末颗粒间较弱的界面结合力导致粒径15~53 μm粉末烧结试样的压缩强度最低,晶化相的析出导致106~250 μm粉末烧结试样的压缩强度低于53~106 μm粉末烧结试样的。Abstract: Three kinds of Zr55Cu30Al10Ni5 amorphous alloy powders with different particle sizes are sintered by spark plasma sintering (SPS) method, and bulk amorphous alloys are prepared. The effect of particle size on amorphous alloy prepared by SPS method is analyzed by testing properties such as density, hardness and compression strength. It is found out that density of the sintered amorphous alloy specimen decreases with the increase of powder size. In the pre-pressing stage of sintering, the densification of powders is achieved by mechanical movement and particle rearrangement, and the smaller the particle size and the closer the particles pack, the higher the densification degree. When the pulse current is applied, compare with the large sized particles, the small sized particles have larger contact area, and the heat transfers faster, which leads to higher densification degree. The hardness of the sintered specimen with particle size of 106-250 μm is the highest, that of the specimen with particle size of 15-53 μm follows, and that of the specimen with particle size of 53-106 μm is the lowest. The non-crystal partly crystallizes, promoting the hardness of the specimen with particle size of 106-250 μm efficiently. The compression strength of the specimen with particle size of 53-106 μm is the highest, that of the specimen with particle size of 106-250 μm follows, and that of the specimen with particle size of 15-53 μm is the lowest. The interface bonding force between the particles small size is weak, making the compression strength of the specimen with particle size of 15-53 μm the lowest, and the precipitation of the crystallized phase contributes to lower compression strength of the specimen with particle size of 106-250 μm than the specimen with particle size of 53-106 μm.
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