阅读说明：本技术 用于高强钛合金热模锻的保温润滑复合材料及制备方法 (Heat-insulating lubricating composite material for hot die forging of high-strength titanium alloy and preparation method thereof ) 是由 张光明 章友谊 蔺虹宾 于 2021-08-19 设计创作，主要内容包括：本发明公开了一种用于高强钛合金热模锻的保温润滑复合材料,依次包括润滑层、保温层、隔热层和反射层,所述润滑层与模具接触,反射层与锻件接触；所述润滑层为石墨层,在模锻时润滑模具；所述保温层为气凝胶毡,在模锻时为锻件保温；所述隔热层为陶瓷纤维纸,降低传导到保温层的热量；所述反射层为铝箔,反射锻件的热辐射。还包括一种复合材料制备方法。采用本发明的用于高强钛合金热模锻的保温润滑复合材料及制备方法,复合材料厚度薄、保温效果好,能够有效提高锻件质量。(The invention discloses a heat-insulating and lubricating composite material for hot die forging of a high-strength titanium alloy, which sequentially comprises a lubricating layer, a heat-insulating layer and a reflecting layer, wherein the lubricating layer is in contact with a die, and the reflecting layer is in contact with a forging piece; the lubricating layer is a graphite layer and is used for lubricating the die during die forging; the heat-insulating layer is made of aerogel felt and is used for insulating a forge piece during die forging; the heat insulation layer is made of ceramic fiber paper, so that heat conducted to the heat insulation layer is reduced; the reflecting layer is an aluminum foil and reflects the heat radiation of the forging. Also discloses a preparation method of the composite material. By adopting the heat-insulating lubricating composite material for the hot die forging of the high-strength titanium alloy and the preparation method thereof, the composite material is thin in thickness and good in heat-insulating effect, and the quality of a forged piece can be effectively improved.)

1. A heat-insulating lubricating composite material for hot die forging of high-strength titanium alloy is characterized in that: the forging die sequentially comprises a lubricating layer, a heat insulation layer and a reflecting layer, wherein the lubricating layer is in contact with the die, and the reflecting layer is in contact with the forging;

the lubricating layer is a graphite layer and is used for lubricating the die during die forging;

the heat-insulating layer is made of aerogel felt and is used for insulating a forge piece in the die forging process;

the reflecting layer is an aluminum foil and reflects the heat radiation of the forging.

2. A heat-insulating lubricating composite material for hot die forging of high-strength titanium alloy is characterized in that: the forging die sequentially comprises a lubricating layer, a heat insulation layer and a reflecting layer, wherein the lubricating layer is in contact with the die, and the reflecting layer is in contact with the forging;

the lubricating layer is a graphite layer and is used for lubricating the die during die forging;

the heat-insulating layer is made of aerogel felt and is used for insulating a forge piece during die forging;

the heat insulation layer is made of ceramic fiber paper, so that heat conducted to the heat insulation layer is reduced;

the reflecting layer is an aluminum foil and reflects the heat radiation of the forging.

3. The heat-insulating lubricating composite material for hot die forging of the high-strength titanium alloy as claimed in claim 1 or 2, wherein: and a fiber cloth is arranged between the heat-insulating layer and the lubricating layer to serve as a transition layer.

4. The heat-insulating lubricating composite material for hot die forging of the high-strength titanium alloy as claimed in claim 3, wherein: the fiber cloth is glass fiber cloth or basalt fiber cloth.

5. The heat-insulating lubricating composite material for hot die forging of the high-strength titanium alloy as claimed in claim 1 or 2, wherein: the thickness of the heat-preservation lubricating composite material is 3-5 mm.

6. The heat-insulating lubricating composite material for hot die forging of the high-strength titanium alloy as claimed in claim 1 or 2, wherein: the graphite layer is formed by adhering graphite powder by taking polyurethane emulsion as a binder.

7. The heat-insulating lubricating composite material for hot die forging of the high-strength titanium alloy as claimed in claim 6, wherein: the graphite layer is prepared from a graphite paste coating, and the graphite paste coating comprises the following components in parts by weight: 90-110 parts of graphite powder, 0.1-0.5 part of sodium carboxymethyl cellulose, 800-1000 parts of water and 20-50 parts of aqueous polyurethane emulsion.

8. A preparation method of a heat-insulating lubricating composite material for hot die forging of high-strength titanium alloy is characterized by comprising the following steps: the method comprises the following steps:

step a: preparing graphite paste coating;

step b: coating graphite paste paint on one side of the aerogel felt;

step c: and adhering aluminum foil or ceramic fiber paper with one side coated with the aluminum foil to the other side of the aerogel felt.

9. The method for preparing a heat-insulating lubricating composite material for hot die forging of a high-strength titanium alloy as claimed in claim 8, wherein: the preparation method of the graphite paste coating comprises the following steps:

step a 1: dissolving 3-5 parts of sodium carboxymethylcellulose into 100 parts of water to prepare sodium carboxymethylcellulose slurry;

step a 2: mixing 90-110 parts of graphite powder, 0.1-0.5 part of sodium carboxymethyl cellulose, 1000 parts of 800-sodium cellulose and 20-50 parts of aqueous polyurethane emulsion in parts by weight, and uniformly stirring to obtain mixed slurry;

step a 3: and (3) placing the mixed slurry into a ball mill for ball milling, and carrying out ball milling for 20-40 min at the speed of 400-600 rpm to obtain the graphite paste coating.

10. The method for preparing a heat-insulating lubricating composite material for hot die forging of a high-strength titanium alloy as claimed in claim 8, wherein: in the step b, the graphite paste coating is firstly coated on one side of the fiber paper, and the other side of the fiber paper is adhered to one side of the aerogel.

Technical Field

The invention relates to a heat-insulating lubricating composite material for hot die forging of a high-strength titanium alloy and a preparation method thereof, belonging to the technical field of die forging.

Background

The titanium alloy forging stock needs to be heated to a certain temperature before forging to improve the plasticity, reduce the deformation resistance and prevent the defects of cracks and the like in the deformation process of metal, but the upper limit of the heating temperature cannot exceed the phase transition temperature of the titanium alloy, because the titanium alloy keeps the temperature above the phase transition temperature for a long time, crystal grains grow up, the mechanical property is reduced, and meanwhile, the gas saturation degree of the surface of the forging stock is increased. On the other hand, a certain transfer transition time is needed from the removal of the titanium alloy forging stock from the high-temperature furnace to the start of forging, and the surface temperature of the forging stock is reduced rapidly in the process.

For high-strength titanium alloy which belongs to near-beta titanium alloy, a quasi-beta forging process is generally adopted, excellent structure and comprehensive performance can be obtained through a process of combining pressure processing and heat treatment, and the method is suitable for manufacturing various large forgings which require high fracture toughness in airplane fuselage and undercarriage structures.

Researches show that when other conditions are fixed, the quasi-beta forging temperature is increased, the interweaving degree and the density degree of the basket structure of the high-strength titanium alloy forging can be greatly increased, and the fracture toughness of the alloy is greatly improved. Therefore, the heat preservation research in the process of strengthening the quasi-beta forging technology of the high-strength titanium alloy is very critical.

At present, the conventional heat insulation cotton with the thickness of 10mm is widely adopted in production. The thicker heat insulation cotton is not beneficial to material swinging of a forging stock in a die cavity on one hand, and on the other hand, the thicker heat insulation cotton often hinders the flow of metal in the die forging process, so that the defects of insufficient filling of the die cavity and the like are caused; in the forming process, a plurality of fine hard particles are left after the heat-insulating cotton quilt is compressed and combusted, and the particles have no lubricating effect but increase friction to enable the forming pressure to rise rapidly.

Therefore, a die forging heat-insulating material with good heat-insulating effect, high lubricity and thin thickness is needed.

Disclosure of Invention

The invention aims to: aiming at the existing problems, the invention provides the heat-preservation lubricating composite material for the hot die forging of the high-strength titanium alloy and the preparation method thereof.

The technical scheme adopted by the invention is as follows:

a heat-insulating and lubricating composite material for hot die forging of high-strength titanium alloy sequentially comprises a lubricating layer, a heat-insulating layer and a reflecting layer, wherein the lubricating layer is in contact with a die, and the reflecting layer is in contact with a forging piece;

the lubricating layer is a graphite layer and is used for lubricating the die during die forging;

the heat-insulating layer is made of aerogel felt and is used for insulating a forge piece in the die forging process;

the reflecting layer is an aluminum foil and reflects the heat radiation of the forging.

In the invention, the aerogel felt is used as a heat insulation layer, the heat conductivity coefficient of the aerogel felt is ultralow, the heat insulation can be effectively realized for the forge piece during die forging, and the use thickness can be effectively reduced by using the aerogel felt under the same heat insulation effect, so that the quality of the forge piece is favorably improved; the aluminum foil as a reflecting layer can effectively reflect the heat radiation of the forging and reduce the heat loss of the forging, so that the heat insulation effect can be further enhanced, the die forging temperature is ensured, meanwhile, the aluminum foil has better toughness and can be bent to adapt to the shape of a composite material laid in a die, the melting point of the aluminum foil is 660 ℃, the aluminum foil can be melted during die forging to play a role in lubricating the forging at high temperature, and the surface quality of the forging is improved; the graphite layer is as the lubricant film, and graphite friction coefficient is low can lubricated mould when the die forging, and aerogel felt can not burn into the granule and hinder the lubrication like the heat preservation cotton during die forging simultaneously to reduce the shaping load, prolong the life of mould and press.

The aerogel felt and the aluminum foil prevent the temperature loss of the forging, reduce the heat loss of the high-strength titanium alloy forging blank and improve the quasi-beta forging temperature, thereby greatly increasing the interweaving degree and the density degree of the basket structure of the high-strength titanium alloy forging and improving the fracture toughness of the alloy.

A heat-insulating and lubricating composite material for hot die forging of high-strength titanium alloy sequentially comprises a lubricating layer, a heat-insulating layer and a reflecting layer, wherein the lubricating layer is in contact with a die, and the reflecting layer is in contact with a forging piece;

the lubricating layer is a graphite layer and is used for lubricating the die during die forging;

the heat-insulating layer is made of aerogel felt and is used for insulating a forge piece during die forging;

the heat insulation layer is made of ceramic fiber paper, so that heat conducted to the heat insulation layer is reduced;

the reflecting layer is an aluminum foil and reflects the heat radiation of the forging.

In the invention, the high temperature resistance of the aerogel felt is lower than that of the ceramic fiber paper, and when the high-initial-forging temperature forging is carried out, the high temperature can damage the structure of the aerogel felt, so that the heat-insulating property of the aerogel felt is reduced, and the die forging effect is influenced; the ceramic fiber paper is arranged between the aerogel felt and the aluminum foil, has the functions of heat insulation and high temperature resistance, so that heat conducted to the aerogel felt by the isolation part is isolated, the high temperature resistance of the aerogel felt is enhanced, the composite material can be applied to alloy forgings with high initial forging temperature, and the application range of the composite material is enlarged.

Preferably, fiber cloth is arranged between the heat-insulating layer and the lubricating layer to serve as a transition layer.

In the scheme, the fiber cloth is arranged for transition, the graphite layer can be coated on the fiber cloth firstly, and the fiber cloth is bonded on the aerogel, so that the composite material is convenient to manufacture.

Preferably, the fiber cloth is glass fiber cloth or basalt fiber cloth.

Preferably, the graphite layer has a thickness of 50 to 100 μm.

Preferably, the aerogel blanket has a thickness of 3-4 mm.

Preferably, the thickness of the heat-preservation lubricating composite material is 3-5 mm.

Preferably, the thickness of the aluminum foil is 0.1 to 0.2 mm.

In the invention, the thickness of the heat-insulating lubricating composite material can be controlled to be 3-5mm, and is only 1/3-1/2 after heat-insulating cotton is used, so that the thickness reduction can be beneficial to the flow of metal in the die forging process, thereby being beneficial to improving the quality of forgings.

Preferably, the graphite layer is formed by adhering graphite powder by using polyurethane emulsion as a binder.

Preferably, the graphite layer is made of graphite paste paint, and the graphite paste paint comprises the following components in parts by weight: 90-110 parts of graphite powder, 0.1-0.5 part of sodium carboxymethyl cellulose, 800-1000 parts of water and 20-50 parts of aqueous polyurethane emulsion.

In the scheme, the aqueous polyurethane emulsion accounts for 2-5% of the mass of the coating and plays a role in bonding and film forming, water plays a role in adjusting viscosity, sodium carboxymethyl cellulose plays a role in thickening, and graphite powder is an effective component. According to the invention, the water-based polyurethane emulsion is selected as a film forming substance, so that the film forming material has good flexibility, and can be bent and folded to adapt to the special-shaped structure of a forging die when being prepared into a heat-insulating composite material. Compared with acrylic emulsion as a film forming substance, the acrylic emulsion has poor flexibility, cannot be bent and folded, cannot adapt to the special-shaped structure of a forging die, and can break and crush a graphite layer when being laid in the die.

A preparation method of a heat-preservation lubricating composite material for hot die forging of a high-strength titanium alloy comprises the following steps:

step a: preparing graphite paste coating;

step b: coating graphite paste paint on one side of the aerogel felt;

step c: and adhering aluminum foil or ceramic fiber paper with one side coated with the aluminum foil to the other side of the aerogel felt.

Preferably, the preparation of the graphite paste coating comprises the following steps:

step a 1: dissolving 3-5 parts of sodium carboxymethylcellulose into 100 parts of water to prepare sodium carboxymethylcellulose slurry;

step a 2: mixing 90-110 parts of graphite powder, 0.1-0.5 part of sodium carboxymethyl cellulose, 1000 parts of 800-sodium cellulose and 20-50 parts of aqueous polyurethane emulsion in parts by weight, and uniformly stirring to obtain mixed slurry;

step a 3: and (3) placing the mixed slurry into a ball mill for ball milling, and carrying out ball milling for 20-40 min at the speed of 400-600 rpm to obtain the graphite paste coating.

Preferably, in step b, the graphite paste coating is coated on one side of the fiber paper, and the other side of the fiber paper is adhered to one side of the aerogel through a flexible adhesive.

Preferably, the graphite paste coating is coated on one side of the fiber paper by adopting a spraying, blade coating or roll coating mode.

Preferably, in step c, the ceramic fiber paper is adhered to the aerogel blanket by flexible glue.

Compared with the existing die forging process technology, under the same other conditions, the composite material prepared by the method can reduce the die forging forming load by 10-30%, reduce the friction coefficient by 30-50% and improve the fracture toughness of the high-strength titanium alloy by 10-15%.

In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:

1. the thickness is thin, and is only 1/3-1/2 of the thickness of the heat-insulating cotton, so that the quality of the forge piece is improved;

2. the heat conductivity coefficient is low, the heat loss of the forging stock can be reduced, the uniform temperature inside and outside the forging stock is ensured, and the forging performance of the forging is improved;

3. the graphite layer has the effect of lubricating the forging die, so that the forming load is reduced, and the service lives of the die and the press machine are prolonged;

4. can be applied to alloy forgings with higher initial forging temperature.

Drawings

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

fig. 1-4 are several schematic structural diagrams of the heat-insulating lubricating composite material.

The labels in the figure are: 1-graphite layer, 2-aerogel felt, 3-aluminum foil, 4-ceramic fiber paper and 5-fiber cloth.

Detailed Description

All of the features disclosed in this specification, or all of the steps in any method or process so disclosed, may be combined in any combination, except combinations of features and/or steps that are mutually exclusive.

Any feature disclosed in this specification may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features.

Example 1

As shown in fig. 1, the heat-insulating lubricating composite material for hot die forging of a high-strength titanium alloy of the present embodiment sequentially includes a lubricating layer, a heat-insulating layer, a reflecting layer, and a reflecting layer;

the lubricating layer is a graphite layer which is in contact with the die, the thickness of the graphite layer is 75 micrometers, and the die is lubricated during die forging; the heat preservation layer is made of aerogel felt, the thickness of the aerogel felt is 4mm, and heat preservation is carried out on the forge piece in the die forging process; the reflection stratum is that the aluminium foil contacts with the forging, and the thickness of aluminium foil is 0.2mm, the heat radiation of reflection forging, prevents the heat loss.

The preparation method comprises the following steps:

step a: preparing a graphite paste coating: 4 parts of sodium carboxymethyl cellulose are dissolved in 100 parts of water to prepare sodium carboxymethyl cellulose slurry; mixing 100 parts of graphite powder, 0.3 part of sodium carboxymethyl cellulose, 900 parts of water and 35 parts of aqueous polyurethane emulsion in parts by weight, and uniformly stirring to obtain mixed slurry; placing the mixed slurry into a ball mill for ball milling at the speed of 500rpm for 30min to obtain graphite paste coating;

step b: spraying the graphite paste coating to one side of the aerogel felt, and drying;

step c: and adhering the aluminum foil to the other side of the aerogel felt to obtain the heat-preservation lubricating composite material.

In the embodiment, the composite material is used for hot die forging of TC21 high-strength titanium alloy, and the fracture toughness K (IC) of the near-surface sample of the die forging piece is 84 Pa.m^1/2。

Example 2

As shown in fig. 2, the heat-insulating lubricating composite material for hot die forging of a high-strength titanium alloy of the present embodiment sequentially includes a lubricating layer, a heat-insulating layer, and a reflecting layer;

the lubricating layer is a graphite layer which is contacted with the die, the thickness of the graphite layer is 50 mu m, and the die is lubricated during die forging; the heat preservation layer is aerogel felt, the thickness of the aerogel felt is 3mm, and the heat preservation layer is used for preserving the heat of the forge piece in the die forging process; the insulating layer is ceramic fiber paper, and ceramic fiber paper's thickness is 1.5mm, and the heat reflection stratum that reduces to conduct the heat preservation is aluminium foil and forging contact, and the thickness of aluminium foil is 0.15mm, and the heat radiation of reflection forging prevents the heat loss.

The preparation method comprises the following steps:

step a: preparing a graphite paste coating: dissolving 3 parts of sodium carboxymethylcellulose into 100 parts of water to prepare sodium carboxymethylcellulose slurry; mixing 90 parts of graphite powder, 0.1 part of sodium carboxymethyl cellulose slurry, 800 parts of water and 20 parts of aqueous polyurethane emulsion in parts by weight, and uniformly stirring to obtain mixed slurry; placing the mixed slurry into a ball mill for ball milling at the speed of 400rpm for 40min to obtain graphite paste coating;

step b: spraying the graphite paste coating to one side of the aerogel felt, and drying;

step c: and adhering an aluminum foil to one side of the ceramic fiber paper, and adhering one side of the ceramic fiber paper without the aluminum foil to the other side of the aerogel felt by using a flexible adhesive to obtain the heat-insulating lubricating composite material.

In the embodiment, the composite material is used for hot die forging of TC21 high-strength titanium alloy, and the fracture toughness K (IC) of the near-surface sample of the die forging piece is 87 Pa.m^1/2。

Example 3

As shown in fig. 3, in this example, in addition to example 1, a glass cloth was provided between the graphite layer and the aerogel blanket.

During preparation, the graphite layer can be coated on the fiber cloth, and then the glass fiber cloth is adhered on the aerogel felt by using the flexible glue, so that the fiber cloth is convenient for manufacturing the composite material.

In the embodiment, the composite material is used for hot die forging of TC21 high-strength titanium alloy, and the fracture toughness K (IC) of the near-surface sample of the die forging piece is 84 MPa.m^1/2。

Example 4

As shown in fig. 4, in this example, in addition to example 2, a glass cloth was provided between the graphite layer and the aerogel blanket.

During preparation, the graphite layer can be coated on the fiber cloth, and then the glass fiber cloth is adhered on the aerogel felt by using the flexible glue, so that the fiber cloth is convenient for manufacturing the composite material.

In the embodiment, the composite material is used for hot die forging of TC21 high-strength titanium alloy, and the fracture toughness K (IC) of the near-surface sample of the die forging piece is 87 MPa-m^1/2。

Comparative example 1

In the comparative example, on the basis of example 1, the aqueous polyurethane emulsion in the graphite paste coating is replaced by the aqueous polyacrylate emulsion.

Compared with the heat-insulating composite material in the embodiment 1, the heat-insulating composite material in the comparative example 1 has poor flexibility and is hard and brittle, and when the heat-insulating composite material is laid in a mould, the graphite layer is directly broken and crushed and cannot be used; the insulating composite material of example 1 was not applied to the mold.

Comparative example 2

The comparative example adopts 10mm common heat-preservation cotton for heat preservation, is used for hot die forging of TC21 high-strength titanium alloy, and the fracture toughness K (IC) of a sample of a die forging piece close to the surface layer is 76 MPa.m^1/2(ii) a In the forming process, a plurality of fine hard particles are left after the heat preservation cotton quilt is compressed and combusted.

Compared with the comparative example 2, in the example 1, the fracture toughness of the high-strength titanium alloy near-surface-layer sample is improved by 10.5 percent; compared with the comparative example 2, in the example 2, the fracture toughness of the high-strength titanium alloy near-surface-layer sample is improved by 14.5 percent;

the invention is not limited to the foregoing embodiments. The invention extends to any novel feature or any novel combination of features disclosed in this specification and any novel method or process steps or any novel combination of features disclosed.