SiC掺杂WC-10Ni硬质合金的真空烧结及性能研究

Study on vacuum sintering and performance of SiC doped WC-10Ni cemented carbide

摘要:

采用高能球磨和真空烧结技术制备了纳米SiC颗粒弥散增强WC-10Ni硬质合金复合材料,研究了SiC添加量和烧结温度对SiC掺杂WC-10Ni硬质合金复合材料显微组织和室温力学性能的影响。结果表明,采用真空烧结技术于1 450 ℃和1 500 ℃下烧结可获得烧结颗粒结合良好,致密度高达99.2%的WC-10Ni-SiC复合材料。SiC的添加不仅可以抑制WC晶粒的长大,起到细化晶粒的作用,还可促使WC晶粒烧结致密化。而且所获得的复合材料的维氏硬度随着SiC含量的增加而提高,最高达1 649 HV；断裂韧性和抗弯强度随着SiC添加量增加均呈现先升高后降低的趋势,当SiC添加量为0.5wt%时可获得断裂韧性和抗弯强度分别为12.7 MPa.m_1/2和1 126.1 MPa的WC-10Ni-SiC硬质合金复合材料。

Abstract:

Nano SiC particles dispersion strengthened WC-10Ni cemented carbide composites were fabricated by high energy ball milling(HEBM) and vacuum sintering(VS). The effects of the SiC content and vacuum sintering temperature on the microstructure and the room temperature mechanical properties of the SiC doped WC-10Ni cemented carbide composites were investigated in this paper. The results showed that the well-combined and highly-densified (nearly 99.2%) WC-10Ni-SiC composites can be obtained by the VS technology at 1 450 ℃ and 1 500 ℃, respectively. The addition of the SiC can not only restrain the growth of WC grains, but also play a role in refining grains, but also accelerate densification of the WC grains sintering. Also the vickers hardness of the prepared composite materials is improved with the increase of SiC content, up to 1 649 HV. Their fracture toughness and flexural strength increased with the increase of the SiC addition and then decreased. The fracture toughness and flexural strength of the WC-10Ni-SiC cemented carbide composites are 12.7 MPa?m_1/2 and 1 126.1 MPa, respectively when the content of the SiC is 0.5wt %.