高能球磨-快速热压烧结工艺制备纳米晶粒WC-Co硬质合金

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

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 ( 13 0 0℃ ) ,较短的保温时间 ( 15min) ,较快的升温速率 ( 12 0℃ /min) ,不太高的压力 ( 3 5MPa)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Cr3 C2 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 2 0 0nm且综合性能较高的纳米WC Co硬质合金块体。

In the present study, bulk nanostructured WC-Co cermets were prepared by high energy ball milling and rapid hot-pressing; the physical and mechanical 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%Cr 3C 2 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.