本文采用X射线衍射(XRD)、扫描电镜(SEM)和性能检测等研究了Cr3C2添加量对WC-6%Co-(0~1.0%)Cr3C2超细晶硬质合金WC粒度、WC形貌及力学性能的影响.结果表明:WC平均晶粒尺寸随Cr3C2 添加量的增加先快速后缓慢减小;添加0.25%Cr3C2后,诱发WC晶粒各向异向生长,WC晶粒形貌呈准三棱柱状,随Cr3C2添加量的增加,WC晶粒形貌更规则,最终变成三棱柱状;随Cr3C2添加量的增加,WC-6%Co-Cr3C2超细晶硬质合金的硬度先快速后缓慢增加,而断裂韧性逐渐降低,抗弯强度先增加后缓慢降低;当添加0.6%Cr3C2时,WC-6%Co硬质合金的综合性能最优,其维氏硬度、抗弯强度和断裂韧性分别为18.42 GPa、3 450 MPa和9.32 MPa·m1/2.
In this paper,the effects of Cr3C2 addition amount on the particle size,morphology,and mechanical properties of ultrafine grained WC-6%Co-(0~1.0%)Cr3C2 cemented carbide were studied by X-ray diffraction(XRD),scanning electron microscopy(SEM),and property detection.The results show that the average grain size of WC decreases rapidly at first and then slowly with the increase in the Cr3C2 addition amount.The addition of 0.25%Cr3C2 induces the anisotropic growth of WC grains,and the morphology of WC grains is a quasi-triangular prism.With the increase in the Cr3C2 addition amount,the morphology of WC grains becomes more regular and finally becomes a triangular prism.With the increase in the addition amount of Cr3C2,the hardness of ultrafine grained WC-6%Co-Cr3C2 cemented carbide first increases rapidly and then slowly,but the fracture toughness gradually decreases,and the bending strength first increases and then slowly decreases.When 0.6%Cr3C2 is added,the comprehensive performance of WC-6%Co cemented carbide is the best,and its Vickers hardness,bending strength,and fracture toughness are 18.42 GPa,3 450 Mpa,and 9.32 MPa·m1/2,respectively.