铁镍替代钴硬质合金的微观结构与性能

发布时间：2018-12-27 11:40

【摘要】：以Fe与Ni部分或全部替代Co作为粘结相,制备硬质合金WC-15Fe-5Ni和WC-13Fe-3Ni-4Co,测试和分析合金的性能与微观结构,并与WC-20Fe合金和传统WC-20Co硬质合金进行对比。结果表明:WC-15Fe-5Ni和WC-13Fe-3Ni-4Co合金的致密度都达到99%以上,抗弯强度比WC-20Fe合金(1 850 MPa)和WC-20Co合金(2 720 MPa)都高,其中以Fe与Ni部分替代Co的WC-13Fe-3Ni-4Co合金,其抗弯强度和硬度都最大,分别为2 880 MPa和1 066.3 MPa。WC-15Fe-5Ni和WC-13Fe-3Ni-4Co合金粘结相中W的溶解量较少,平均晶粒尺寸小,晶粒形貌多为边界圆滑的多面体,Ni和Co固溶于Fe中,起到固溶强化作用;这2种合金的弯曲断口存在明显的粘结相塑性变形撕裂,自腐蚀电流密度分别为4.26×10~(-4) A/cm~2和1.86×10~(-4) A/cm~2,均接近WC-20Co合金的自腐蚀电流密度3.27×10~(-5),比WC-20Fe合金的自腐蚀电流密度(4.34×10~(-2) A/cm~2)低2个数量级。
[Abstract]:The properties and microstructure of cemented carbides prepared by WC-15Fe-5Ni and WC-13Fe-3Ni-4Co, were tested and analyzed by using Fe and Ni partially or wholly instead of Co as bonding phase. The results were compared with WC-20Fe alloys and traditional WC-20Co cemented carbides. The results show that the density of both WC-15Fe-5Ni and WC-13Fe-3Ni-4Co alloys is over 99%, and the flexural strength is higher than that of WC-20Fe alloys (1 850 MPa) and WC-20Co alloys (2 720 MPa). The flexural strength and hardness of WC-13Fe-3Ni-4Co alloy partially replaced by Fe and Ni are the highest, which are 2 880 MPa and 1 066.3 MPa.WC-15Fe-5Ni and WC-13Fe-3Ni-4Co respectively. The average grain size is small, and the grain morphology is mostly polyhedron with smooth boundary. Ni and Co are solid solution in Fe, which plays a solid solution strengthening role. The bending fracture of these two alloys has obvious plastic deformation tear of bond phase. The corrosion current density of the two alloys is 4.26 脳 10 ~ (-4) A/cm~2 and 1.86 脳 10 ~ (-4) A / cm ~ (-2), respectively, and the corrosion current density of the two alloys is 1.86 脳 10 ~ (-4) A / cm ~ (-2). The corrosion current density of WC-20Co alloy is 3.27 脳 10 ~ (-5), which is two orders of magnitude lower than that of WC-20Fe alloy (4.34 脳 10 ~ (-2) A/cm~2).
【作者单位】：中南大学材料科学与工程学院;
【基金】：湖南有色研究基金资助项目(20120619)
【分类号】：TG135.5

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