阅读说明：本技术 一种用于无镀铜焊丝的表面涂层材料及其制备方法和应用 (Surface coating material for copper-free welding wire and preparation method and application thereof ) 是由 周海龙 宋昌宝 续杰 汪涛 包润新 于 2020-05-26 设计创作，主要内容包括：本发明提供了一种用于无镀铜焊丝的表面涂层材料及其制备方法和应用,该表面涂层材料包括按质量百分比计的如下组分：基础油85～90％、聚四氟乙烯4～10％、纳米二氧化钛1～2％、氧化锡0.6～1.3％、纳米锑粉0.2～0.6％、稳弧剂1.5～2.5％。该发明通过添加纳米二氧化钛、纳米锑粉等成分提高送丝性能、降低导电嘴磨损率的同时兼顾优良的导电性,同时硼酸钾和碳酸钠等稳弧剂的添加提高了无镀铜焊丝的电弧稳定性,减低飞溅,使得焊接工艺性得到很大提高,通过汉诺威定量测定电流电压变异系数降低5～10％,飞溅率降低10～15％。(The invention provides a surface coating material for a copper-free welding wire, and a preparation method and application thereof, wherein the surface coating material comprises the following components in percentage by mass: 85-90% of base oil, 4-10% of polytetrafluoroethylene, 1-2% of nano titanium dioxide, 0.6-1.3% of tin oxide, 0.2-0.6% of nano antimony powder and 1.5-2.5% of an arc stabilizer. According to the invention, the wire feeding performance is improved by adding components such as nano titanium dioxide and nano antimony powder, the wear rate of the contact tube is reduced, and the excellent conductivity is taken into consideration, meanwhile, the arc stability of the copper-free welding wire is improved by adding arc stabilizers such as potassium borate and sodium carbonate, the splashing is reduced, the welding manufacturability is greatly improved, the current-voltage variation coefficient is reduced by 5-10% through quantitative determination of Hannover, and the splashing rate is reduced by 10-15%.)

1. A surface coating material for a copper-free welding wire is characterized by comprising the following components in percentage by mass: 85-90% of base oil, 4-10% of polytetrafluoroethylene, 1-2% of nano titanium dioxide, 0.6-1.3% of tin oxide, 0.2-0.6% of nano antimony powder and 1.5-2.5% of an arc stabilizer.

2. The surface coating material for a copper-free welding wire according to claim 1, wherein the base oil is palm oil or animal fat oil.

3. The surface coating material for a copper-free welding wire according to claim 1, wherein the polytetrafluoroethylene has a diameter of not more than 20 μm.

4. The surface coating material for the copper-free welding wire according to claim 1, wherein the sum of the mass of the nano titanium dioxide, the mass of the tin oxide and the mass of the nano antimony powder accounts for 1.8-3.9% of the total mass of the surface coating material.

5. The surface coating material for the copper-free welding wire according to claim 1, wherein the size of the nano titanium dioxide and the size of the nano antimony powder are both controlled to be 50-150 nm.

6. The surface coating material for the copper-free welding wire according to claim 1, wherein the arc stabilizer is one or a mixture of potassium borate and potassium carbonate, and the mass ratio of the mixture of potassium borate and potassium carbonate is 2: 1.

7. The method for preparing the surface coating material for the copper-free welding wire according to any one of claims 1 to 6, comprising the steps of:

1) placing the base oil in a reactor, heating to 80-100 ℃, and stirring for 30 min;

2) mixing polytetrafluoroethylene, nano titanium dioxide, tin oxide, nano antimony powder and an arc stabilizer, shaking for 1h, fully and uniformly mixing, putting into the reactor in the step 1), heating to 80-100 ℃, stirring for 40min, and standing to obtain the surface coating material.

8. The copper-plating-free welding wire is characterized by comprising a welding wire base body and the surface coating material for the copper-plating-free welding wire, wherein the surface coating material is coated on the surface of the welding wire base body, and the surface coating material is as defined in any one of claims 1 to 6.

9. The copper-free welding wire as claimed in claim 8, wherein the surface coating material is applied by reducing and over-molding, and the application process conditions are that the diameter of the prefabricated welding wire is slightly smaller than that of the finished welding wire, the neck-fixing compression ratio is controlled to be 5-15%, and the coating amount of the surface coating material is controlled to be 6-10 mg/m²。

10. The copper-free welding wire according to claim 8, wherein the surface coating material is applied by electrostatic spraying under the conditions that the diameter of the neck is set to the diameter of the finished welding wire and the coating amount of the surface coating material is controlled to be 4-10 mg/m²。

Technical Field

The invention belongs to the technical field of welding materials, and particularly relates to a surface coating material for a copper-free welding wire, and a preparation method and application thereof.

Background

Along with the continuous development of welding equipment, degree of automation is constantly improved, and the use of gas shielded solid welding wire is more and more general, but traditional gas shielded solid welding wire is mainly with copper facing welding wire, still has a series of problems in production and use: the acid and alkali pollution is serious in the production process, the electroplating energy consumption is high, and the environment is not protected; the copper plating layer is easy to fall off, so that the electrochemical corrosion is aggravated, and a wire feeding hose is blocked, so that the rust prevention is poor and the wire feeding is not smooth; the problems of large splashing, large welding smoke dust, poor forming and the like exist in the using process, and the wide application in automatic equipment is influenced.

The advent of copper-free welding wire has pointed out the direction to solve the above problem, but the following bottlenecks remain: poor rust resistance, serious abrasion of the contact tube, poor conductivity and the like. At present, the production of the welding wire without copper plating is mainly carried out by surface oiling and coating, the problems of rust resistance or contact nozzle abrasion are mainly solved, but all the problems cannot be considered, for example, the problems of uneven coating, unstable surface quality and the like cannot be solved by adopting a coating mode of felt or titration or solid powder die coating.

Disclosure of Invention

The invention aims to solve the problems of poor antirust performance, serious abrasion of a contact tube, poor conductivity and the like of the existing copper-free welding wire.

Therefore, the invention provides a surface coating material for a copper-free welding wire, which comprises the following components in percentage by mass: 85-90% of base oil, 4-10% of polytetrafluoroethylene, 1-2% of nano titanium dioxide, 0.6-1.3% of tin oxide, 0.2-0.6% of nano antimony powder and 1.5-2.5% of an arc stabilizer.

Further, the base oil is palm oil or animal fat oil.

Further, the diameter of the polytetrafluoroethylene is not more than 20 μm.

Furthermore, the sum of the mass of the nano titanium dioxide, the mass of the tin oxide and the mass of the nano antimony powder accounts for 1.8-3.9% of the total mass of the surface coating material.

Furthermore, the sizes of the nano titanium dioxide and the nano antimony powder are both controlled to be 50-150 nm.

Further, the arc stabilizer is one or a mixture of potassium borate and potassium carbonate, and the mass ratio of the potassium borate to the potassium carbonate is 2: 1.

In addition, the invention also provides a preparation method of the surface coating material for the copper-free welding wire, which comprises the following steps:

1) placing the base oil in a reactor, heating to 80-100 ℃, and stirring for 30 min;

2) mixing polytetrafluoroethylene, nano titanium dioxide, tin oxide, nano antimony powder and an arc stabilizer, shaking the powder for 1h, putting the mixture into the reactor in the step 1) after fully and uniformly mixing, heating to 80-100 ℃, stirring for 40min, and standing to obtain the surface coating material.

The invention also provides a copper-plating-free welding wire which comprises a welding wire substrate and the surface coating material for the copper-plating-free welding wire, wherein the surface coating material is coated on the surface of the welding wire substrate.

Furthermore, the coating mode of the surface coating material is reducing over-mold coating, the coating process conditions are that the diameter of the prefabricated welding wire is slightly smaller than that of the finished welding wire, the compression ratio of the fixed neck is controlled to be 5-15%, and the coating amount of the surface coating material is controlled to be 6-10 mg/m²。

Further, the coating mode of the surface coating material is electrostatic spraying, the coating process conditions are that the diameter of a neck is determined as the diameter of a finished welding wire, and the coating amount of the surface coating material is controlled to be 4-10 mg/m²。

In the invention, the base oil mainly plays a role in isolating air and playing a role in rust prevention; the polytetrafluoroethylene mainly acts as lubrication and reduces the drawing and wire feeding resistance, and when the diameter of the polytetrafluoroethylene is more than 20 mu m, polytetrafluoroethylene particles cannot form suspension in base oil, and the coating uniformity is influenced, so that the antirust performance is reduced, and the diameter of the polytetrafluoroethylene is controlled to be less than 20 mu m; the nano titanium dioxide, the tin oxide and the nano antimony powder mainly have the main effects of reducing the abrasion of the contact tube and improving the conductivity, and experimental research shows that the performance of the nano titanium dioxide, the tin oxide and the nano antimony powder is influenced by the size of nano particles, the nano particles with the size controlled within 50-150 nm have good lubricity, the abrasion loss of the contact tube is reduced, and the stability of an electric arc is improved; the arc stabilizer (potassium borate and potassium carbonate) has the functions of improving the stability of the electric arc and reducing splashing.

Compared with the prior art, the invention has the beneficial effects that:

(1) the surface coating material for the copper-free welding wire improves wire feeding performance by adding components such as nano metal oxide titanium dioxide and nano antimony powder, reduces wear rate of a contact tube, gives consideration to excellent conductivity, improves arc stability of the copper-free welding wire by adding arc stabilizers such as potassium borate and sodium carbonate, reduces splashing, greatly improves welding manufacturability, reduces current and voltage variation coefficient by 5-10% through quantitative determination of Hannover, and reduces splashing rate by 10-15%.

(2) The surface coating material coated on the surface of the copper-free welding wire provided by the invention has the characteristics of isolation, rust prevention, arc stabilization and low resistivity, and improvement on grinding environment, solves the problems of pipe blockage caused by copper powder dropping and full corrosion caused by coating coverage of a coating of the traditional copper-free welding wire, and the like, and meanwhile, the rust prevention property of the welding wire is greatly improved by forming the isolation layer on the surface of the welding wire, and air is not corroded after being exposed for 2 months.

The present invention will be described in further detail below with reference to the accompanying drawings.

Drawings

FIG. 1 is a graph comparing wear of contact tips welded with and without copper plated wire in accordance with an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.