阅读说明：本技术 一种激光增材制造微弧火花MCrAlY电极的方法 (Method for manufacturing micro-arc spark MCrAlY electrode by laser additive manufacturing ) 是由 迟长泰 韩旭 陈书 林慧超 曾增伟 郭善赞 仲才 于 2019-12-09 设计创作，主要内容包括：本发明属于金属激光增材制造领域,具体为一种激光增材制造微弧火花MCrAlY电极的方法,适用于多种尺寸微弧火花MCrAlY电极的制备。首先预热激光沉积基材到一定温度,采用一定粒度的MCrAlY粉末,在真空手套箱中用同步送粉方法进行激光沉积,沉积过程中用一定流量的氩气覆盖激光沉积作用区,利用感应加热保持基材在一定温度,可实现沉积层组织致密均匀,无明显气孔夹杂等缺陷；然后采用线切割切取增材层一定直径和长度的圆柱,将圆柱体表面车光滑并进行清洗处理,同时进行结构成分及孔隙率分析,从而确保了MCrAlY电极的纯度和致密性。本发明为制造MCrAlY电极提供了高效、稳定、可靠的新型工艺方法,对微弧火花表面增材制造及改性方面具有重要意义。(The invention belongs to the field of metal laser additive manufacturing, and particularly relates to a method for manufacturing a micro-arc spark MCrAlY electrode by laser additive manufacturing, which is suitable for preparing micro-arc spark MCrAlY electrodes with various sizes. Firstly, preheating a laser deposition base material to a certain temperature, adopting MCrAlY powder with a certain granularity, carrying out laser deposition in a vacuum glove box by using a synchronous powder feeding method, covering a laser deposition action area with argon gas with a certain flow in the deposition process, and keeping the base material at a certain temperature by using induction heating, so that the compact and uniform structure of a deposition layer can be realized, and the defects of obvious air hole inclusion and the like are avoided; and then cutting a cylinder with a certain diameter and length of the additive layer by adopting linear cutting, turning and smoothing the surface of the cylinder, cleaning, and analyzing structural components and porosity simultaneously, thereby ensuring the purity and compactness of the MCrAlY electrode. The invention provides a novel efficient, stable and reliable process method for manufacturing the MCrAlY electrode, and has important significance on the aspects of material increase manufacturing and modification of the surface of the micro-arc spark.)

1. A method for manufacturing a micro-arc spark MCrAlY electrode by laser additive manufacturing is characterized by comprising the following process steps:

adopting MCrAlY powder, drying at 100-200 ℃, and cooling to room temperature after drying; selecting a base material according to the deposited MCrAlY powder, wherein the base material and the MCrAlY powder have wettability and welding performance, and preheating to 150-300 ℃ after the surface of the base material is polished; in a vacuum glove box environment, a synchronous powder feeding-laser deposition mode is adopted, and a light beam with one light spot is selected to carry out laser deposition treatment on a base material; in the deposition process, the temperature of the base material is adjusted at any time according to the temperature of the base material, the base material is heated by an induction coil to be kept at 150-450 ℃, and meanwhile, a protective gas is adopted to protect a laser action area and purify the laser action area; and then cutting the additive layer electrode by adopting a wire cut electrical discharge machine, polishing and smoothing the surface of the electrode, cleaning, and analyzing structural components and porosity simultaneously, thereby ensuring the high purity and compactness of the MCrAlY electrode.

2. The method for laser additive manufacturing of a micro-arc spark MCrAlY electrode according to claim 1, wherein the MCrAlY powder has a particle size of 100-300 meshes, a sphericity of 92% or more and an oxygen content of 500PPM or less.

3. The method of claim 1, wherein the drying process comprises placing MCrAlY powder in a vacuum oven for more than 1.5 hours.

4. The method of laser additive manufacturing of a micro-arc spark MCrAlY electrode according to claim 1, characterized by vacuum glove box environment, H₂O≤50PPM、O₂≤50PPM。

5. The method for laser additive manufacturing of a micro-arc spark MCrAlY electrode according to claim 1, characterized in that the process parameters of laser deposition are as follows:

continuous laser irradiation, wherein the laser power is 500-3000W, and the power density is 10⁴～10⁶W/cm²Scanning speed2-25 mm/s, 30-60% of lap joint amount and 2-6 mm of irradiation light spot;

the powder feeding mode is coaxial argon powder feeding, the powder feeding speed is 3.5-25 g/min, argon protection is adopted, and the flow of protective gas is 5-20L/min.

6. Method for laser additive manufacturing of a micro-arc spark MCrAlY electrode according to claim 1 or 5, characterized in that the laser deposited laser is a fiber laser, a semiconductor laser, a CO laser₂YAG laser or Nd.

7. The method for manufacturing the micro-arc spark MCrAlY electrode according to claim 1, wherein a wire-cut electric discharge machine is adopted to cut the cylindrical micro-arc electric discharge electrode with a certain diameter and length of the additive layer, the length is 25-75 mm, and the diameter is phi 2.5-phi 7 mm.

8. The method of claim 1, wherein the electrode surface is polished smooth and cleaned, the electrode surface is finished by a lathe and a grinder, and then the electrode surface is cleaned with alcohol.

9. The method of claim 1, wherein structural composition and porosity analysis of the electrode is performed, structural composition analysis is performed using X-ray diffraction and chemical analysis, and porosity analysis is performed using an optical microscope and CT scanning.

10. The method for laser additive manufacturing of a micro-arc spark MCrAlY electrode according to claim 1, wherein the MCrAlY powder processed by the method has uniform and compact structure after laser deposition, high chemical purity of more than 96wt percent and porosity of less than 0.1 percent.

Technical Field

The invention belongs to the field of metal laser additive manufacturing, and particularly relates to a method for manufacturing a micro-arc spark MCrAlY electrode by laser additive manufacturing, which is suitable for preparing micro-arc spark MCrAlY (M ═ Ni, Co or Ni + Co) electrodes with various sizes.

Background

The laser deposition additive manufacturing is a new manufacturing technology, high-power laser is used as a heat source, raw materials such as powder and the like which are synchronously conveyed are fused and fused by laser, additive manufacturing is realized by melting and stacking layer by layer, and molding manufacturing of metal parts with any complex shapes is realized.

Micro-arc spark deposition is a pulse arc micro-welding process, which is a method of capacitance discharge and micro-arc fusion welding, and utilizes short-time electric pulses formed by controllable energy discharge to generate metallurgical bonding surface modification or forming. Compared with laser surface treatment, micro-arc spark surface treatment has smaller heat influence on a matrix, basically does not cause workpiece deformation and texture change of matrix materials, and many materials which cannot be welded by the conventional welding method can be welded by micro-arc sparks frequently.

The conventional preparation method of the micro-arc spark MCrAlY electrode mainly comprises powder metallurgy and conventional fusion welding, the electrode formed by the conventional fusion welding is short in time consumption and high in efficiency, but the shape of the electrode is difficult to control, the porosity is high, and the prepared electrode is generally short; the powder metallurgy preparation electrode has good forming effect, but needs to be carried out under high vacuum for a long time, and has poor economic timeliness; the method for manufacturing the micro-arc spark MCrAlY electrode by adopting the laser additive can effectively combine the advantages of the two, quickly and efficiently prepare the MCrAlY electrode, and is stable and reliable. Therefore, the research and invention of the method for manufacturing the micro-arc spark MCrAlY electrode by laser additive manufacturing has important practical value for the application of the micro-arc spark deposition technology, and the reliability and the stability of the micro-arc spark additive and the surface modification are effectively improved.

Disclosure of Invention

In order to solve the problem of high-purity rapid preparation of the micro-arc spark MCrAlY electrode and further improve the reliability and stability of micro-arc spark additive and surface modification, the invention aims to provide the method for manufacturing the micro-arc spark MCrAlY electrode by laser additive.

The technical scheme of the invention is as follows:

a method for manufacturing a micro-arc spark MCrAlY electrode by laser additive manufacturing comprises the following process steps:

adopting MCrAlY powder, drying at 100-200 ℃, and cooling to room temperature after drying; selecting a base material according to the deposited MCrAlY powder, wherein the base material and the MCrAlY powder have wettability and welding performance, and preheating to 150-300 ℃ after the surface of the base material is polished; in a vacuum glove box environment, a synchronous powder feeding-laser deposition mode is adopted, and a light beam with one light spot is selected to carry out laser deposition treatment on a base material; in the deposition process, the temperature of the base material is adjusted at any time according to the temperature of the base material, the base material is heated by an induction coil to be kept at 150-450 ℃, and meanwhile, a protective gas is adopted to protect a laser action area and purify the laser action area; and then cutting the additive layer electrode by adopting a wire cut electrical discharge machine, polishing and smoothing the surface of the electrode, cleaning, and analyzing structural components and porosity simultaneously, thereby ensuring the high purity and compactness of the MCrAlY electrode.

According to the method for manufacturing the micro-arc spark MCrAlY electrode by using the laser additive, MCrAlY powder has the granularity of 100-300 meshes, the sphericity of more than or equal to 92% and the oxygen content of less than or equal to 500 PPM.

According to the method for manufacturing the micro-arc spark MCrAlY electrode by laser additive manufacturing, MCrAlY powder is placed in a vacuum drying box for more than 1.5 hours in a drying treatment.

The method for manufacturing the micro-arc spark MCrAlY electrode by using the laser additive, the vacuum glove box environment H₂O≤50PPM、O₂≤50PPM。

According to the method for manufacturing the micro-arc spark MCrAlY electrode by using the laser additive, the laser deposition process parameters are as follows:

continuous laser irradiation, wherein the laser power is 500-3000W, and the power density is 10⁴～10⁶W/cm²The scanning speed is 2-25 mm/s, the lapping amount is 30-60%, and the irradiation light spot phi is 2-6 mm;

the powder feeding mode is coaxial argon powder feeding, the powder feeding speed is 3.5-25 g/min, argon protection is adopted, and the flow of protective gas is 5-20L/min.

The laser deposition laser is fiber laser, semiconductor laser and CO₂YAG laser or Nd.

According to the method for manufacturing the micro-arc spark MCrAlY electrode by laser additive manufacturing, a cylindrical micro-arc electric spark electrode with a certain diameter and length of an additive layer is cut by a wire cut electrical discharge machine, the length is 25-75 mm, and the diameter is phi 2.5-phi 7 mm.

The method for manufacturing the micro-arc spark MCrAlY electrode by the laser additive comprises the steps of polishing and smoothing the surface of the electrode, cleaning, finely processing the surface of the electrode by using a lathe and a grinding machine, and cleaning the surface of the electrode by using alcohol.

The method for manufacturing the micro-arc spark MCrAlY electrode by the laser additive comprises the steps of analyzing the structural components and the porosity of the electrode, analyzing and inspecting the structural components by X-ray diffraction and chemical analysis, and analyzing and inspecting the porosity by an optical microscope and CT scanning.

According to the method for manufacturing the micro-arc spark MCrAlY electrode by using the laser additive, the MCrAlY powder processed by the method is uniform and compact in structure after laser deposition, high in chemical purity which is up to more than 96 wt%, and low in porosity which is lower than 0.1%.

The design idea of the invention is as follows:

the MCrAlY powder with good sphericity is adopted, after drying treatment, the laser deposition base material is preheated to a certain temperature, then laser deposition is carried out in a vacuum glove box by a synchronous powder feeding method, argon with a certain flow is used for covering a laser deposition action area in the deposition process, and induction heating is utilized for maintaining the base material at a certain temperature, so that laser additive manufacturing with compact and uniform deposition layer tissues and no defects of cracks, air holes, inclusion and the like can be realized; adopting wire cut electrical discharge machining to cut the electrical discharge electrodes with different diameters and lengths from the MCrAlY additive layer: firstly, the surface of the electrode is smoothened, then the electrode is cleaned, and finally the structural components and the porosity are analyzed, so that the high purity and the good compactness of the MCrAlY electrode are ensured.

The conventional preparation method of the micro-arc spark MCrAlY electrode mainly comprises powder metallurgy and conventional fusion welding, the electrode formed by the conventional fusion welding is short in time consumption and high in efficiency, but the shape of the electrode is difficult to control, the porosity is high, and the prepared electrode is generally short; the electrode prepared by powder metallurgy has good forming effect, but needs to be carried out under high vacuum for a long time, has poor economic timeliness, and has the limitation of size not too long and is easy to break after too long.

The method for manufacturing the micro-arc spark MCrAlY electrode by adopting the laser additive can effectively combine the advantages of fusion welding and powder metallurgy for preparing the MCrAlY electrode, and avoids the defects of high porosity, poor timeliness and poor economy of the two. The method can be used for quickly and efficiently preparing the MCrAlY electrode, and the MCrAlY deposited layer manufactured by using the vacuum glove box in an additive manufacturing mode has high purity and no obvious inclusion cracks; meanwhile, the method is less in size under the restriction conditions such as electrodes and the like, can prepare electrodes with various lengths and diameters, and has good controllability; in addition, the electrode manufactured by the additive has good chemical component purity and formability, and the good quality of the micro-arc electrode is stably ensured. The method also introduces the technologies of X-ray diffraction, chemical analysis, CT scanning and the like to test the quality of the micro-arc electrode, and realizes the preparation procedure of the micro-arc spark MCrAlY electrode from preparation to detection of a complete chain. The method has important practical value for the application of the micro-arc spark deposition technology, effectively improves the reliability and stability of the micro-arc spark additive and surface modification, and fundamentally solves the problem of good and reliable matching of the preparation quality and the aging of the micro-arc spark MCrAlY electrode and other micro-arc spark electrodes.

The invention has the advantages and beneficial effects that:

1. according to the method for manufacturing the micro-arc spark MCrAlY electrode by using the laser additive, provided by the invention, the flatness of the laser deposition MCrAlY additive layer is improved, the internal stress of the additive layer is reduced, the defects such as cracks and the like in the additive layer are avoided, and the formation of the additive layer without the defects such as crack inclusion and the like in various sizes and shapes is effectively controlled by adopting a synchronous powder feeding-laser deposition mode and a mode of keeping the temperature of the base material constantly. More importantly, the micro-arc spark MCrAlY electrode manufactured by laser additive manufacturing has high efficiency and good economy, and a solution is provided for manufacturing the micro-arc spark MCrAlY electrode controlled deposition by laser additive manufacturing.

2. The laser additive manufacturing is carried out in a vacuum glove box, the water oxygen content is low, and the chemical purity of the MCrAlY additive layer manufactured by the laser additive is ensured, so that the high purity of the micro-arc spark electrode is ensured, and the micro-arc spark additive manufacturing method is of great importance to the good performance of the micro-arc spark deposition coating.

3. The invention realizes the laser additive manufacturing that the laser deposition MCrAlY structure is more compact, uniform and consistent, and the defects of few holes, cracks and inclusions are completely eliminated, realizes the higher compactness of the micro-arc spark electrode, and the inside of the electrode is good metallurgical bonding.

4. The invention introduces the technologies of X-ray diffraction, chemical analysis, CT scanning and the like to test the quality of the micro-arc electrode and realizes the preparation procedure of the micro-arc spark MCrAlY electrode from preparation to detection of a complete chain.

Drawings

FIG. 1 is a comparison graph of porosity of three sets of welded, powder metallurgy and laser additive manufactured micro arc spark MCrAlY electrodes.

Detailed Description

In the specific implementation process, MCrAlY powder with good sphericity is adopted, drying treatment is carried out for more than 1.5 hours in a vacuum drying oven at the temperature of 100-200 ℃, and cooling to room temperature after drying is finished; selecting a base material according to the deposited MCrAlY powder, wherein the base material and the MCrAlY powder have good wettability and good welding performance, and preheating to 150-300 ℃ after the surface of the base material is polished; in a vacuum glove box environment, a synchronous powder feeding-laser deposition mode is adopted, and a light beam with one light spot is selected to carry out laser deposition treatment on a base material; in the deposition process, induction heating and heat preservation are utilized to maintain the base material at a certain temperature, protective gas is adopted to protect the laser action area, and the laser action area is purified; then cutting an electrode with a certain diameter and length from the additive layer by adopting a wire cut electrical discharge machine, and smoothing and cleaning the surface of the electrode; and finally, analyzing the purity and the porosity of the structural components, thereby ensuring the high purity and the good compactness of the MCrAlY electrode.

The following description of the preferred embodiments of the present invention is provided for the purpose of illustration and description, and is in no way intended to limit the invention.