Novel system for preparing spherical powder through plasma atomization

Abstract

The invention discloses a novel system for preparing spherical powder through plasma atomization. The novel system for preparing spherical powder through plasma atomization comprises a feeding device, one or more plasma cabinets, an atomization tower, a vacuum pump and an air supply device, wherein the vacuum pump and the air supply device are both connected with the atomization tower, and the air supply device is used for supplying inert gas. The novel system for preparing spherical powder through plasma atomization further comprises a powder screening device, and a discharge outlet of the atomization tower is connected with the powder screening device. The plasma cabinets are mounted at the top of the atomization tower. The atomization tower comprises an inner wall and an outer wall, and a water-cooling interlayer is formed between the inner wall and the outer wall. The multiple plasma cabinets are arranged, raw materials in the molten state are impacted while raw materials are molten through a gathering focus point of a plurality of angled jet flows by means of the high-temperature and high-speed jet flows, and the particle size of powder is effectively reduced; and an atomization main body is cooled rapidly through the water-cooling interlayer, so that atomized materials are cooled at a high cooling speed, and the quality and sphericity of collected fine powder are increased.

Description

technical field [0001] The invention relates to a plasma atomization system, in particular to a novel plasma atomization system for preparing spherical powder. Background technique [0002] With the rapid development of additive manufacturing technology (also known as 3D printing), metal injection molding (MIM), thermal spraying and other technologies, the market demand for metal powder, especially high-quality spherical metal powder is increasing. The types of metal powders demanded by the market include titanium, nickel, molybdenum, cobalt, copper, iron, aluminum, stainless steel and other metals and their alloy powders. [0003] At present, the commonly used processes for preparing metal powders include mechanical alloying, thermal reduction, molten electrolysis, and atomization. Among them, the atomization method is the main process for preparing spherical metal powder. At present, the commonly used atomization methods in China include electrode-induced gas atomization ...

AI Technical Summary

Problems solved by technology

However, there are still many problems in the current EIGA technology: the induction coil limits the diameter of the raw material bar of the induction electrode, and the large-diameter electrode requires a higher induction heating power supply and induction coil, and the cost is higher; in order to ensure that the electrode stays stably in the coil, the vertical feeding speed How to cooperate with the rotation speed of the electrode is also a complicated problem, and the problem still needs to be solved; after the electrode is heated and melted by induction, it flows into the gas atomization nozzle, and the metal droplets should maintain a stable and continuous flow state without interruption, and there will be liquid in the actual atomization process. Drops, or the electrode is not completely melted and breaks off and falls into the draft tube, causing blockage

However, the PREP process is limited by technical bottlenecks such as sealing and vibration caused by a large increase in the speed of the electrode rod, and the fixed length of the electrode rod cannot guarantee the continuity of the atomization, the atomization efficiency is low, the high-speed rotation of the electrode is easy to wear the shaft, and the powder produced The particle size is relatively large, with an average particle size of about 150um

However, 3D printing, metal injection molding and other technologies require fine particle size powders below 45um. It is difficult to prepare fine particle size powders that meet the requirements at low cost by this method.

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