选区激光烧结WC-10％Co颗粒增强Cu基复合材料的显微组织

Microstructure of the WC-10%Co Particulate Reinforced Cu Matrix Composites Fabricated by Selective Laser Sintering

利用选区激光烧结工艺制备了WC-10％Co颗粒增强Cu基复合材料,其中WC-Co和Cu的质量比为30:70。X射线衍射和扫描电镜分析证实,粉末激光成形是基于液相烧结机制,其中Cu,Co充当粘结相,WC充当增强相:而激光作用的非平衡性导致形成亚稳相CoC0.25。WC增强颗粒具有3种典型形态(未熔且团聚、部分熔化且部分团聚、熔化且弥散),表明粒径较大的WC以颗粒重排为主要成形机制,而粒径较小的WC则以溶解-析出为主导机制。烧结试样显微硬度平均值HV0.1为3898 MPa,且分布平稳。

The WC-10%Co particulate reinforced Cu matrix composite material with the WC-Co： Cu weight ratio of 30：70 was successfully produced using selective laser sintering （SLS） process. The scanning electron microscope （SEM） and X-ray diffraction （XRD） analyses show that the bonding mechanism of this process is liquid phase sintering, during which the Cu and the Co act as the binder phase, while the WC acts as the reinforcing phase. The non-equilibrium effects induced by the laser beam give rise to the formation of a metastable phase CoC0.25. The WC reinforced particulates typically have three distinct morphologies, i.e., undissolved and agglomerated, partially dissolved and incompletely separated, and dissolved and separated. Rearrangement acts as a dominant forming mechanism for the larger WC particles, while dissolution-precipitation prevails for the smaller WC particles. The microhardness distribution of the laser sintered part is uniform with a high average HV0.1 value of 3898 MPa