放电等离子烧结制备纳米SiC_p/Al复合材料及组织性能研究

以微米级、纳米级碳化硅(SiC)颗粒和纯铝(Al)粉为原料,通过高能球磨+放电等离子烧结(SPS)工艺制备了不同质量分数的SiC颗粒增强Al基复合材料(SiC_p/Al),研究了SiC颗粒尺寸和含量对复合材料组织性能的影响。结果表明:高能球磨能促进增强颗粒的均匀分布,放电等离子烧结具有烧结温度低、保温时间短的特点,可有效减少甚至避免基体与增强体有害反应的发生。纳米级SiC增强铝基复合材料的颗粒团聚趋势较大,复合材料致密度较低,但是其细晶强化和Orowan强化效果显著,包含源缺陷和源裂纹较少,因此,复合材料硬度和屈服强度相应提高。

Microstructure and Properties of Nano-SiC/Al Composites Fabricated by SPS

Micro?and nano?silicon carbide ( SiC) particles and pure aluminum ( Al) powder were used as raw materials to prepare SiC particulate?reinforced aluminum?based composites with different mass fractions by ball milling and spark plasma sintering. The effect of size and amount of SiC particles on the microstructure and properties of the composite were studied. The results show that high energy ball milling can effectively improve the uniform distribution of SiC particles. SPS has the characteristics of low sintering temperature and short holding time, which can effectively reduce or even avoid harmful reactions between the matrix and the reinforcement. For the nano?SiC/Al composite, the particle agglomeration increased while the density decreased, but the effects of grain refinement and Orawan strengthening were greatly improved, with decreased defects and fractures. The yield strength and hardness of the SiC/Al composites enhanced thereby.