Development of Elcctrode Material for Plasma Cutting by Laser Furnace

本研究旨在研制等离子切割用耐久电极材料，并对电极的耐久性能及其消耗机理进行了探讨。尝试将激光引入到等离子切割电极材料的烧结中。在这种激光炉法中，可以烧结高熔点的材料，如Hf或Hf化合物。在本研究中，与金属Hf粉末相比，Hf N粉末很难烧结，在300W的激光功率下，1.8K的激光功率下，可以由金属粉末制备Hf N。笔者认为，激光熔炼法对未来高熔点材料的烧结或氮化是有益的。从氧气氛下到200A的电弧电流消耗试验结果来看，含10-25wt%氧化钇的Ir电极比目前广泛使用的Hf电极具有更好的抗烧蚀性能。尤其是Ir-15wt%Y_2O_3电极，在25A的氧化等离子弧下，其寿命约为Hf电极的3倍，而且良好的耐蚀性很大程度上依赖于氧化层的形成作为良好的电子发射体。

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.