Ni包裹SiC对SiC(Ni)/Fe复合材料性能的影响

Effect of Ni-Coated SiC Particles on the Mechanical Properties of SiC/Fe Composite

分别以SiC粉体和Ni包裹的SiC复合粉体为硬质相,采用热压工艺(1000°C,20°C/min,40 MPa和45 min)制备了SiC含量为1 wt%~9 wt%的SiC/Fe复合材料。采用扫描电镜(SEM)、能谱仪(EDS)和X射线衍射仪(XRD)等研究了复合材料的界面反应物。研究结果表明:Ni过渡层的存在有效避免了SiC颗粒与Fe基体之间的化学反应。随着Ni包裹SiC粉体含量的增加,复合材料的相对密度和抗弯强度先增加后减小,当SiC(Ni)粉体含量为5 wt%时达到最大值。

SiC/Fe composites containing1wt%,3wt%,5wt%,7wt%and9wt%of uncoated or Ni-coated SiC particles were prepared respectively by vacuum hot-pressed sintering at40MPa,20oC/min,1000°C for45min.The effect of Ni-coated SiC particles on the densification of SiC(Ni)/Fe composites was investigated by relating their properties with their microstructure and crystallographic information.It was shown that Ni-coated SiC composite powders were beneficial for the microstructure and properties of the reinforced iron-based composites due to the promotion of neck formation and growth between SiC and iron powders during sintering,which enhanced the relative density of the sintered compact and the bonding strength between SiC particles and the iron matrix.The density and bending strength of SiC(Ni)/Fe composites got their peaks when the content of SiC(Ni)powder kept at5wt%.