A method for coating the surface of a titanium alloy wire by hot upsetting

Abstract

The present invention discloses a method for coating the surface of a titanium alloy wire during hot upsetting. The steps include skinning and polishing, brushing a water-based graphite lubricating and demolding agent, brushing a curing protective agent, and drying and curing. The coating formed by the curing protective agent of the present invention has strong adhesion, can significantly improve the firmness of the coating of the water-based graphite lubricating and demolding agent, and effectively solve the lubrication and demolding problems during the hot upsetting forming process; moreover, the lubrication and demolding are excellent, which can effectively reduce the friction between the titanium alloy wire and the die when upsetting fasteners, ensure uniform metal deformation, avoid upsetting cracks, extend the die life, the formed fasteners are easy to clean, and improve production efficiency; during the heating process of upsetting processing, the curing protective agent begins to fail (burn out) at 300-400 °C, which does not affect the efficacy of the water-based graphite lubricating and demolding agent, and can meet the requirements of continuous upsetting processing of titanium alloy fasteners in the military field.

Description

Technical Field

[0001] The present invention relates to the field of titanium alloy processing, and particularly to a method for coating the surface of a hot upset titanium alloy wire with a coating. Background Art

[0002] With the rapid development of China's aerospace industry and the continuous improvement of the performance requirements for advanced aircraft, the demand for a new generation of titanium alloy fasteners for aerospace applications is increasing, and the comprehensive performance requirements for fasteners are also getting higher and higher. In order to improve the production efficiency and quality stability of fasteners in China, many domestic fastener production units have imported several continuous upsetting fastener production equipment from abroad. This equipment must use large single-weight coil wire as the raw material for upsetting fasteners to give full play to the equipment advantages and achieve the purpose of efficient and stable production.

[0003] Since the upsetting processing method used in fastener production makes the material prone to cracking, and in severe cases, it may even lead to the scrapping of the mold. In order to ensure the lubrication effect during the upsetting process, improve the metal flow state on the surface of the material during upsetting, and reduce the upsetting cracking phenomenon, it is necessary to coat a self-lubricating coating on the surface of the titanium alloy wire, so as to solve the upsetting cracking problem in the processing of coil wire and improve the yield rate of fastener production. At present, water-based graphite lubricating and releasing agents are mostly used for lubrication and demoulding by one-time application, but there are problems such as poor adhesion of the water-based graphite lubricating and releasing agent coating, which easily leads to lubrication and demoulding problems during the hot upset forming process. When upsetting fasteners, the friction between the titanium alloy wire and the mold is large, the metal deformation difference is large, cracks are likely to appear, and the life of the mold is affected. Summary of the Invention

[0004] Therefore, based on the above background, the present invention provides a method for coating the surface of a hot upset titanium alloy wire with a coating, which uses a water-based graphite lubricating and releasing agent in combination with a curing protective agent to finally form a coating on the titanium alloy wire layer with strong adhesion and easy to clean after high-temperature heating and upset forming.

[0005] The technical solution of the present invention is as follows:

[0006] A method for coating the surface of a hot upset titanium alloy wire with a coating, characterized by comprising the following steps:

[0007] S1: Debark and polish the surface of the titanium alloy wire;

[0008] S2: After the titanium alloy wire is at room temperature or heated, brush the water-based graphite lubricating and releasing agent and then dry it;

[0009] S3: Brush the curing protective agent and then dry it;

[0010] S4: After the wire is coiled, dry and cure the whole coil of wire;

[0011] The water-based graphite lubricating mold release agent consists of the following components by weight:

[0012] Fine graphite 20%-40%, adhesive 3%-7%, dispersant 0.5%-1%, and water 40%-70%.

[0013] The curing protective agent consists of the following components by weight: propylene glycol methyl ether 50%-70%, perfluorohexane 20%-40%, ethylene glycol 1%-3%, propylene glycol ethyl ether 2%-5%, and perfluorooctyltrimethoxysilane 2%-5%.

[0014] Preferably, the heating temperature in step S2 is 70-120°C.

[0015] Preferably, the drying temperature in step S2 is 100-150°C.

[0016] Preferably, the drying temperature in step S3 is 150-260°C.

[0017] Preferably, the drying and curing temperature in step S4 is 150-260°C.

[0018] Preferably, the final coating thickness in step S4 is 0.05-0.25 mm.

[0019] Preferably, the particle size of the fine graphite is 4-16 μm.

[0020] Preferably, the dispersant is selected from propylene glycol block polyethers.

[0021] Preferably, the adhesive is selected from aluminum silicate.

[0022] The beneficial effects achieved by the present invention are as follows:

[0023] The present invention uses a curing protective agent to protect the firmness of the water-based graphite lubricating mold release agent on the wire surface without affecting the efficacy of the graphite lubricating mold release agent: the coating formed by the curing protective agent has strong adhesion, can significantly improve the firmness of the coating of the water-based graphite lubricating mold release agent, effectively solve the lubricating mold release problem in the hot heading forming process; and has excellent lubricating mold release performance, can effectively reduce the friction between the titanium alloy wire and the mold when forging fasteners, ensure uniform metal deformation, avoid forging cracks, extend the mold life, the formed fasteners are easy to clean, and improve production efficiency; during the heating process of forging, the curing protective agent starts to fail (burn out) at 300-400°C, and the working temperature of the remaining graphite coating can reach 700-900°C, which can meet the requirements of continuous forging processing of titanium alloy fasteners in the military field. Detailed implementation mode

[0024] Reference will now be made in detail to embodiments of the present invention, one or more examples of which are described below. Each example is provided by way of explanation and not limitation of the present invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the scope or spirit of the present invention. For example, features illustrated or described as part of one embodiment can be used in another embodiment to yield a still further embodiment.

[0025] Accordingly, it is intended that the present invention cover such modifications and variations that fall within the scope of the appended claims and their equivalents. Other objects, features, and aspects of the present invention are disclosed in or will be apparent from the following detailed description. Those of ordinary skill in the art should understand that this discussion is merely a description of exemplary embodiments and is not intended to limit the broader aspects of the present invention. The present invention will be further described below with reference to embodiments.

[0026] Example 1: A method for coating the surface of a titanium alloy wire by hot upsetting, characterized in that it comprises the following steps:

[0027] S1: Debark and polish the surface of the titanium alloy wire;

[0028] S2: After the titanium alloy wire is at room temperature or heated to 70 - 120°C, brush on a water-based graphite lubricating release agent and then dry it at 100 - 150°C for 3 - 5 minutes;

[0029] S3: After brushing on the curing protective agent, dry it at 150 - 260°C for 3 - 5 minutes;

[0030] S4: After the wire is coiled into a coil, bake and cure the entire coil of wire at 150 - 260°C for 30 - 60 minutes; Through repeated experimental verification, when using the baking and curing temperatures outside the above range, for example, if the baking temperature is too high, the coating will fail, and if it is too low, the firmness of the coating will decrease. Therefore, the baking temperature in this step is optimally controlled at 150 - 260°C.

[0031] The water-based graphite lubricating release agent consists of the following weight components:

[0032] Fine graphite with a particle size of 4 - 16μm: 40%, adhesive: 7%, dispersant: 1%, water: 52%.

[0033] The curing protective agent consists of the following weight components: propylene glycol monomethyl ether: 60%, perfluorohexane: 30%, ethylene glycol: 2%, propylene glycol monoethyl ether: 4%, perfluorooctyltrimethoxysilane: 4%.

[0034] The dispersant is selected from propylene glycol block polyether. The adhesive is selected from aluminum silicate.

[0035] The final coating thickness in step S4 is 0.1 mm.

[0036] In the present invention, compared with the existing technologies, after brushing the water-based graphite lubricating demoulding agent, a curing protective agent is brushed. The curing protective agent can enhance the firmness of the water-based graphite lubricating demoulding agent on the surface of the wire and prevent it from being eroded by water or scratched off by hard objects; and it can prevent the premature shedding of the water-based graphite lubricating demoulding agent, so that it cannot play a lubricating and demoulding role during hot forging.

[0037] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

Claims

1. A method for coating the surface of a titanium alloy wire by hot upsetting, characterized in that It includes the following steps: S1: Debark and polish the surface of the titanium alloy wire; S2: After the titanium alloy wire is at room temperature or heated, brush on a water-based graphite lubricating and demoulding agent and then dry it; S3: Brush on a curing protective agent and then dry it; S4: After the wire is coiled into a circle, dry and cure the whole coil of wire; The drying and curing temperature in step S4 is 150 - 260 °C; The water-based graphite lubricating and demoulding agent consists of the following weight components: fine graphite 20% - 40%, adhesive 3% - 7%, dispersant 0.5% - 1%, and water 40% - 70%; The curing protective agent consists of the following weight components: propylene glycol monomethyl ether 50% - 70%, perfluorohexane 20% - 40%, ethylene glycol 1% - 3%, propylene glycol monoethyl ether 2% - 5%, and perfluorooctyltrimethoxysilane 2% - 5%; The dispersant is selected from propylene glycol block polyether; the adhesive is selected from aluminum silicate.

2. The method for coating the surface of a hot upset titanium alloy wire according to claim 1, characterized in that, The heating temperature in step S2 is 70 - 120 °C.

3. A method for coating a surface of a hot upset titanium alloy wire according to claim 1, characterized in that, The drying temperature in step S2 is 100 - 150 °C.

4. A method for coating a surface of a hot-forged titanium alloy wire according to claim 1, characterized in that, The drying temperature in step S3 is 150 - 260 °C.

5. A method for coating the surface of a hot-forged titanium alloy wire according to claim 1, characterized in that, The final coating thickness in step S4 is 0.05 - 0.25 mm.

6. The method for coating the surface of a hot upset titanium alloy wire according to claim 1, characterized in that, The particle size of the fine graphite is 4 - 16 μm.