Study On Preparation Technology And Property Of La-Mo Alloy Powder

RE-Mo alloy plate not only has good high-temperature strength and creep resistance performance,but also has excellent plasticity at room temperature after high-temperature annealing,its general mechanical properties prior to Si-Al-K alloy mixed with Mo and TZM.The main applications of RE-Mo alloy plate are heat shield of modern high-temperature furnace,structural parts,plate electrodes,manufacturing components of strip,etc.La-Mo powder is the raw material of molybdenum plate production.The uniformity and performance indicators of La element play a crucial role in improving the performance of La-Mo alloy plate.The preparation of RE-Mo alloy powder is the premise and basic of the development of RE-Mo alloy slab technology.Therefore,the study of alloy molybdenum powder is particularly important.In this paper,three doping methods(solid-solid doping,solid-liquid doping, liquid-liquid doping) were used to mix molybdenum powder with La₂O₃.The proper doping method was selected by measuring and comparing the uniformity of La₂O₃ in molybdenum powder.Through adjusting processing parameters(temperature,material thickness,hydrogen flow,etc.) in reduction process,this paper identified the production process of La-Mo alloy powder,and produced La-Mo alloy powder in which the content of La₂O₃ was 0.2～0.3%,0.5～0.7%,0.9～1.0%and the distribution was very uniform.The particle size,pattern,phase and chemical composition of La-Mo alloy powder were measured by laser particle size analyzer,scanning electron microscopy,X-ray diffractmeter and ICP.The La-Mo alloy powder and pure molybdenum powder were compared to study the effects of La₂O₃ on properties of La-Mo alloy powder. The results show that RE oxide La₂O₃ refined molybdenum powder particles. Molybdenum powder had the regular shape.The content of oxygen increased with increasing the addition of La₂O₃.The distribution uniformity of La element in molybdenum powder produced by solid-liquid doping method was better than that produced by solid-solid doping method and liquid-liquid doping method,and the content of La₂O₃ was easy to control.