Abstract La2O3/WC-10Co mixed-powders with different amounts of La2O3 were prepared by ball milling. Then, the powders were pressed and consolidated by microwave sintering. The microstructure and mechanical properties of the La2O3/WC-10Co alloys with different La2O3 contents were investigated. The experimental results show that addition of an appropriate amount of La2O3 can suppress WC grain growth and narrow the grain size distribution. With the addition of a small amount of La2O3, the nanosize La2O3 particles mainly distribute at the interfaces between the WC and Co phases. However, excessive addition of La2O3 leads to aggregation, forming large particles with a size of approximately 200 nm. Two types of interface relationships were observed between the La2O3 and WC phases in the samples. One is that of the well-coherent interface, and the other is that of the poorly coherent interface where structural disorder is found in the 1–3 nm wide region between the La2O3 and WC phases. However, this structural disorder does not occur in the interfaces between Co and La2O3 phases. Addition of a minor amount of La2O3 into the alloys has less effect on the relative density of the La2O3/WC-10Co alloys. Regarding the mechanical properties, when the La2O3 content is 0.8 wt% (the mass ratio of La2O3 in Co), the Rockwell hardness and fracture toughness of the La2O3/WC-10Co alloys reach 91.8 HRA and 13.44 MPa m1/2, respectively. The transverse rupture strength (TRS) has a maximum value of 2359 MPa when the La2O3 content is 1.2 wt%.

中文翻译：

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添加La2O3的超细晶WC-10Co合金的制备及性能

摘要 采用球磨法制备了不同La2O3含量的La2O3/WC-10Co混合粉体。然后，通过微波烧结对粉末进行压制和固结。研究了不同La2O3含量的La2O3/WC-10Co合金的显微组织和力学性能。实验结果表明，加入适量的La2O3可以抑制WC晶粒长大，缩小晶粒尺寸分布。添加少量 La2O3 后，纳米尺寸的 La2O3 颗粒主要分布在 WC 和 Co 相之间的界面处。然而，过量添加 La2O3 会导致聚集，形成大小约为 200 nm 的大颗粒。在样品中的 La2O3 和 WC 相之间观察到两种类型的界面关系。一个是连贯的界面，另一个是相干性差的界面，在 La2O3 和 WC 相之间的 1-3 nm 宽区域中发现结构无序。然而，这种结构紊乱不会发生在 Co 和 La2O3 相之间的界面中。在合金中加入少量的 La2O3 对 La2O3/WC-10Co 合金的相对密度影响较小。在力学性能方面，当La2O3 含量为0.8 wt%（Co 中La2O3 的质量比）时，La2O3/WC-10Co 合金的洛氏硬度和断裂韧性分别达到91.8 HRA 和13.44 MPa m1/2。当 La2O3 含量为 1.2 wt% 时，横向断裂强度 (TRS) 的最大值为 2359 MPa。这种结构紊乱不会发生在 Co 和 La2O3 相之间的界面中。在合金中加入少量的 La2O3 对 La2O3/WC-10Co 合金的相对密度影响较小。在力学性能方面，当La2O3 含量为0.8 wt%（Co 中La2O3 的质量比）时，La2O3/WC-10Co 合金的洛氏硬度和断裂韧性分别达到91.8 HRA 和13.44 MPa m1/2。当 La2O3 含量为 1.2 wt% 时，横向断裂强度 (TRS) 的最大值为 2359 MPa。这种结构紊乱不会发生在 Co 和 La2O3 相之间的界面中。在合金中加入少量的 La2O3 对 La2O3/WC-10Co 合金的相对密度影响较小。在力学性能方面，当La2O3 含量为0.8 wt%（Co 中La2O3 的质量比）时，La2O3/WC-10Co 合金的洛氏硬度和断裂韧性分别达到91.8 HRA 和13.44 MPa m1/2。当 La2O3 含量为 1.2 wt% 时，横向断裂强度 (TRS) 的最大值为 2359 MPa。La2O3/WC-10Co 合金的洛氏硬度和断裂韧性分别达到 91.8 HRA 和 13.44 MPa m1/2。当 La2O3 含量为 1.2 wt% 时，横向断裂强度 (TRS) 的最大值为 2359 MPa。La2O3/WC-10Co 合金的洛氏硬度和断裂韧性分别达到 91.8 HRA 和 13.44 MPa m1/2。当 La2O3 含量为 1.2 wt% 时，横向断裂强度 (TRS) 的最大值为 2359 MPa。