Development of Elcctrode Material for Plasma Cutting by Laser Furnace

为开发耐久性等离子切割电极材料，对电极的耐久性及其消耗机理进行了探讨。尝试了将激光束引入到等离子切割电极材料的烧结中。在本研究中，氮化铪粉末较金属铪粉末难烧结，可以在300 W激光功率下，1.8ks的时间内由金属粉末制备氮化铪粉末。我认为激光熔覆法在将来用于高熔点材料的烧结或氮化是有用的。从氧气氛下直到200 A的电弧电流下的消耗测试结果来看，含10-25wt%氧化钇的Ir电极与目前广泛使用的铪电极相比具有良好的抗侵蚀性。在25 A的氧化等离子弧作用下，Ir-15wt%Y_2O_3电极的寿命是铪电极的3倍左右，其良好的耐腐蚀性能与氧化层的形成密切相关，氧化层是良好的电子发射体。

This study was carried out to develop the durable electrode materials for plasma cutting and was discussed the durability of electrode and its cosumption mechanism. It was attempted that the new type furnace introduced the laser beam apply to sintering the electrode materials for plasma cutting. In this method of the laser furnace, the high melting meterial such as hafnium or hafnium compound can be sintered.In this study, it is abvious that hafnium nitride powder is difficult to sintering compared with hafnium metal powder, and can be made of hafnium nitride from metal powder at 300W in laser power for 1.8ks. I think that the laser furnce method is useful to sintering or nitridizing of the high melting material in the future.Ir including 10-25wt% yttrium oxide electrode has a good erosion resistance compared with hafnium electrode of the widely used in today from the results of consumption test under the oxygen atmosphere until 200A in arc current. Especially, Ir-15wt%Y_2O_3 electrode shows about three times life-time compared with hafnium electrode under the oxidizing plasma arc at 25A.And the good erosion resistance is strongly depended on the formation of oxide layr acts as a good electron emitter.