高能球磨-快速热压烧结工艺制备纳米晶粒WC-Co 硬质合金

采用高能球磨-快速热压烧结工艺制备了纳米晶粒WC-Co 硬质合金块体, 并对合金的物理、力学性能及微观组织进行了分析测试。研究结果表明:高能球磨合成的纳米WC-Co 复合粉末通过快速热压烧结, 可在较低的烧结温度(1 300 ℃), 较短的保温时间(15 min), 较快的升温速率(120 ℃/min), 不太高的压力(35 MPa)下获得高致密的纳米硬质合金块体;通过添加0.8%的VC 和0.2%的Cr₃C₂ 作为晶粒生长抑制剂, 并采用低温、短时、快速、加压烧结的快速热压烧结工艺, 在一定程度上控制了纳米WC 晶粒的快速长大, 制备出了平均晶粒尺寸约为200 nm 且综合性能较高的纳米WC-Co 硬质合金块体。

Preparation of Bulk Nanostructured WC-Co Cermets by High Energy Ball Milling and Rapid Hot-Pressing

In the present study, bulk nanostructured WC-Co cermets were prepared by high energy ball milling and rapid hotpressing;the physical andmechanical properties as well as microstructure of the sintered bulk materials were also measured.It was shown that highly-compacted WC-Co cermets (99.9 %)could be achieved by rapid hot-pressing sintering at lower temperature(1 300 ℃), shorter soaking time(15 min), higher heating rate(120 ℃/min)and lower pressure(35 MPa).Rapid growth of WC crystal grains could be controlled to a certain extent by adding 0.8 %VC and 0.2 %Cr₃C₂ as crystal growth inhibitors and using the rapid hot-pressing sintering technology, preparing bulk nanostructured WC-Co cements, which have a mean size of 200 nm and a good comprehensive performance.