添加TiC和Cr_3C_2对超细WC-8Co硬质合金微观结构和性能的影响

Effect of TiC and Cr_3C_2 Addition on Microstructures and Properties of Ultrafine WC-8Co Cemented Carbides

在WC-8Co硬质合金中添加不同含量的TiC和Cr3C2,用X射线衍射、扫描电镜分析了添加微量的TiC与Cr3C2对WC-8Co硬质合金微观结构的影响,通过硬度和断裂韧性测试,研究了TiC与Cr3C2含量对材料力学性能的影响。实验结果表明:添加适量TiC和Cr3C2能使超细硬质合金中WC晶粒尺寸细小且晶粒分布更为均匀,微观结构得以优化,从而改善硬质合金力学性能。此外,添加微量TiC能起到细化WC晶粒的作用,提高合金硬度,而添加Cr3C2能够显著抑制硬质合金中硬脆Co6W6C相的形成,从而改善合金的断裂韧性。

With adding various contents of TiC and Cr3C2 into the WC-8Co ultrafine cemented carbides,the effects of the TiC or Cr3C2 addition on the microstructure and mechanical properties of the cemented carbides were investigated by X-ray diffraction（ XRD）,scanning electron microscopy（ SEM）,hardness and fracture toughness test,respectively. The results show that alloys with homogeneous microstructure and ultrafine grain structure forms,and excellent properties are obtained when the optimal proportion of TiC or Cr3C2 is added. Moreover,Minor TiC addition refines the WC grains and increases the hardness of the alloys,while the addition of Cr3C2 decreases the volume fraction of Co6W6C phase in ultrafine WC-8Co alloys and thus increases the fracture toughness of alloys.