Ce在钼合金中的存在形态及其对力学性能的影响

OCCURRENCE STATUS OF Ce ELEMENT IN Mo ALLOY AND ITS EFFECTS ON THE MECHANICAL PROPERTIES OF MO ALLOY

实验研究了稀土元素Ce在钼丝制备过程中的存在形态以及对其性能的影响。结果表明,在通过MoO2粉末和Ce(NO3)3溶液的固-液掺杂、还原获得的Mo-Ce合金粉末中,Ce元素以CeO2形态存在;在烧结坯中,较大尺寸的CeO2质点分布于晶界,较小尺寸的CeO2质点分布于晶内;在丝材成形过程中,晶内CeO2质点逐渐变形为纤维状,晶界CeO2质点仍呈球状,未发生变形。CeO2的存在不但细化了钼粉,同时弥散分布在烧结坯基体中,起到了一定的韧化作用。对不同Ce含量的Mo-Ce合金而言,CeO2存在形式有所不同,导致其塑性有所差异。

The occurrence status and effect of rare-earth Ce addition on properties of Mo alloy wires have been investigated during the preparation of Mo wires.The results show that in Mo-Ce alloy powders which were prepared by the solid-liquid doping method and reducing processing in the present of H2 as reducing agent,Ce exsists in the form of CeO2.CeO2 particles with larger size distribute in grain boundaries of Mo and smaller CeO2 in the crystal boundaries of Mo in sintered Mo-Ce rods.In the wire forming process,internal CeO2 particles gradually become fibrous,but CeO2 in the boundaries is still of ball particles.Due to CeO2,the grain sizes of Mo powders are refined.Dispersed distribution of CeO2 in sintering bulk play the role of toughening.There are differences in the plasticity of Mo-Ce alloy with different level because of different forms of CeO2.