原位冶金反应氧化钨制备碳化钨

在密闭和开放两种环境下,采用原位合成法在采掘机截齿齿体(20CrMnTi)的齿顶孔内制备钨基硬质合金,研究了原位反应的热力学原理、产物的微观组织、成分、相组成及其形成机理。结果表明:在非平衡快速凝固条件下,凝固组织内应力较大,内部有裂纹出现。在相对密闭的环境下反应,生成的产物是W、W2C、Al2O3。W或W2C与Al2O3的界面清晰,产物多孔且硬度高。采用电弧为外加热源,开口情况下WO3大量汽化,导致钨元素大量损失,产物中钨元素的含量很低,几乎没有生成W2C和WC。最后,文中列举了解决这些问题的几种改进措施。

Insitu Metallurgical Reaction Preparation of Tungsten Carbide from Tungsten Oxide

In this paper, the Wbased hard alloy tool bit was produced by insitu metallurgy reaction at open and closed environment respectively in the tip hole of coal mining machine cutting pick (20CrMnTi). In the experimental, the thermodynamic principle of the insitu reaction and the microstructure of the products were analised, and the formation mechanism of microstructure, composition, and phase composition of the products were also analised. The results show that in the nonequilibrium solidification progress during insitu reaction, the solidification stress is large and then lead to some internal cracks. In response to the relatively closed environment, the products are W, W₂C and Al₂O₃. The interface of them is very clear, the products is porous and very hard. As heated by the arc, a large number of vaporization of WO₃ in the open systerm, leading to a significant loss of tungsten, tungsten content in the products is very low and only a little W₂C and WC is found. Finally, the paper gives some solutions to these problems.