双尺度WC-CoCr涂层的组织结构分析

Morphology of the WC-CoCr coatings with micro-nano composite structure

微纳米复合结构的碳化钨涂层的性能引人关注。以纳米碳化钨(≤200nm)、亚微米碳化钨(0.8μm)和微米碳化钨(2μm)为原料,制备了两种双尺度的微纳米复合结构碳化钨喷涂粉末,采用超音速火焰喷涂工艺制备了相应的涂层。利用扫描电镜、能量色散X射线光谱仪和透射电镜对涂层的物相结构进行了分析。结果表明,纳米微米复合粉涂层中的碳化钨保留率为96.7%;纳米亚微米复合粉末制备的涂层碳化钨保留率为92.5%。两种涂层中,W_2C均分布在WC附近,大颗粒WC颗粒仍保持原来的尖角形,小尺度WC颗粒部分呈圆角形,纳米-亚微米涂层中Co_3W_3C相分散于WC与非晶相之间。

The property of the tungsten carbide powder with micro-nano composite structure has drawn a lot of attention recently. Two kinds of tungsten carbide powder with micro-nano composite structure were prepared from nano tungsten carbide（≤200nm）, submicro tungsten carbide（0.8μm） and micro tungsten carbide（2μm） and their coatings were produced by high velocity oxygen fuel. The morphologies of coatings were characterized via scanning electron microscopy, energy dispersive X-ray spectrometry and transmission electron microscopy. The results show the tungsten carbide retains 96.7% in the nano-micro composite coating while 92.5% in the nano-submicro one. The WC particles are distributed near W2C ones, the morphology of the large WC particle remains accuminate shape while part of the small one presents rounded shape in both of the two composite coatings. The phase of Co3W3C distributes between the phase of WC and amorphous phase in the nano-submicro composite coating.