High bonding strength bimetallic layered composite material and its preparation process

Abstract

The present invention belongs to the technical field of metal composite plate preparation and relates to a high-bonding-strength bimetallic layered composite material and its preparation process, comprising the following steps: material preparation: cutting titanium alloy and cemented carbide as raw materials, cutting iron foil and vanadium foil as intermediate layer materials, and surface treating the raw materials and intermediate layer materials respectively; stacking the surface-treated raw materials and intermediate layer materials in the order of cemented carbide / iron foil / vanadium foil / titanium alloy to form a composite blank to be composited; placing the composite blank in a hot pressing furnace for hot pressing and diffusion composite bonding. After the hot pressing and diffusion composite bonding is completed, the blank is cooled to room temperature in the furnace and removed to prepare the bimetallic layered composite material. The use of the Fe / V composite intermediate layer material in the present invention can reduce interfacial residual stress and effectively avoid the formation of malignant brittle interlayer compounds. The resulting titanium alloy / hard alloy composite plate has high interfacial bonding strength, with an interfacial shear strength of at least 120 MPa.

Description

Technical Field

[0001] The invention belongs to the technical field of metal composite plate preparation, and relates to a high-bonding-strength titanium alloy / hard alloy bimetallic layered composite material and a preparation process thereof. Background Art

[0002] Bimetallic layered composites are new materials composed of two metals, presenting in the form of plates, tubes and rods. Bimetallic layered composites can combine the advantages of each component metal, achieve complementary advantages, and obtain excellent comprehensive performance. Titanium alloy has a low density (~4.5g / cm 3 ), high specific strength, good plasticity and excellent corrosion resistance, etc., and are widely used in aerospace, marine engineering and other fields. However, the wear resistance of titanium alloys is poor. Cemented carbide is composed of a hard phase and a binder, such as WC hard phase and Co metal binder (tungsten cobalt cemented carbide), which has excellent wear resistance. However, the density of cemented carbide is generally high. For example, the density of the most common tungsten cobalt cemented carbide is ~14g / cm 3 Combining lightweight, high-strength and tough titanium alloys with wear-resistant cemented carbides into bimetallic layered composite materials can achieve lightweight, high-strength, high-toughness and high wear resistance, and has important application potential in the fields of marine and national defense.

[0003] Good interface bonding (higher interface bonding strength) is the prerequisite for bimetallic layered composite materials to achieve excellent overall performance. At present, the commonly used composite methods for preparing bimetallic layered composite materials include solid-liquid composite method, solid-solid composite method, etc. In the solid-liquid composite method, due to the high temperature, thicker interlayer brittle and hard compounds are often produced between heterogeneous metals, higher residual stress is introduced, etc., and the prepared interface bonding strength is often lower. The solid-solid composite method specifically has different forms such as hot rolling composite method, explosion composite method, diffusion composite method. Among them, diffusion composite method has the characteristics of relatively low temperature and small deformation, and is widely used in the preparation of bimetallic layered composite materials.

[0004] The thermal expansion coefficient of titanium alloy is relatively large (9.4~10.5×10 -6 / K), while the thermal expansion coefficient of cemented carbide is relatively low (4~6×10 -6 / K), the thermal expansion coefficient gap between the two materials is relatively large. In the cooling process of diffusion composite, as the temperature decreases, the two materials shrink differently, which will cause a relatively large residual stress between the two materials, which may significantly reduce the interface bonding strength. In addition, Ti and WC, Ti and Co, etc. may react to generate intermetallic compounds, which will also reduce the interface bonding strength. For this reason, when performing titanium alloy / cemented carbide hot pressing diffusion composite, in order to reduce the residual stress concentration at the joint interface and avoid generating intermetallic compounds at the interface, it is necessary to select suitable hot pressing diffusion composite parameters and intermediate layer materials. Summary of the Invention

[0005] In view of this, an object of the present invention is to provide a bimetallic layered composite material with high bonding strength and a preparation process thereof, so as to solve the problems raised in the background technology.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A process for preparing a high-bonding-strength bimetallic layered composite material comprises the following steps:

[0008] S1. Material preparation: cutting titanium alloy and cemented carbide as raw materials, cutting iron foil and vanadium foil as intermediate layer materials, and performing surface treatment on the raw materials and intermediate layer materials respectively;

[0009] S2. stacking the raw materials obtained after surface treatment and the intermediate layer materials in the order of cemented carbide / iron foil / vanadium foil / titanium alloy to form a composite blank to be composited;

[0010] S3. The composite blank is placed in a hot pressing furnace for hot pressing and diffusion compounding. After the hot pressing and diffusion compounding is completed, the blank is taken out after cooling to room temperature in the furnace to prepare a titanium alloy / hard alloy bimetallic layered composite material with high bonding strength.

[0011] Furthermore, the cemented carbide consists of a hard phase and a binder phase.

[0012] Furthermore, the hard phase is WC, and the bonding phase is Co.

[0013] Furthermore, the iron foil is industrial pure iron, and the vanadium foil is industrial pure vanadium.

[0014] Furthermore, in step S1, the surface treatment process of the titanium alloy in the raw material is as follows: the surface of the titanium alloy used for compounding is polished with sandpaper to remove the cutting marks and oxide layer on the polished surface, and after ensuring that there is no oxide layer on the polished surface, it is cleaned with alcohol and blown dry, and then the cut titanium alloy is pickled with a chemical corrosive agent, and then blown dry for use after cleaning.

[0015] Furthermore, the chemical etching agent is V(HF):V(HNO3):V(H2O)=3:9:40.

[0016] Furthermore, in step S1, the surface treatment process of the cemented carbide in the raw material is as follows: grinding the surface of the cemented carbide used for composite with diamond sandpaper to remove the cutting marks and oxide layer on the polished surface of the cemented carbide, cleaning it with alcohol and then drying it for later use.

[0017] Furthermore, in step S1, the surface treatment process of the iron foil and the vanadium foil is as follows: the surfaces of the iron foil and the vanadium foil used for composite are polished with sandpaper to remove the oxide layer, and after removing the cutting marks and the oxide layer on the polished surfaces of the iron foil and the vanadium foil, ultrasonic cleaning is performed, and then the surfaces are rinsed with alcohol and blown dry for use.

[0018] Furthermore, in step S3, the temperature of the hot pressing diffusion composite is 850° C. to 950° C., the pressing pressure is 10 to 20 MPa, and the holding time is 40 to 60 minutes.

[0019] Furthermore, the hot pressing furnace is in a vacuum environment or an inert atmosphere to prevent oxidation of the raw materials and the intermediate layer materials.

[0020] A high-bonding-strength bimetallic layered composite material comprises a high-bonding-strength titanium alloy / hard alloy bimetallic layered composite material prepared by the preparation process of the high-bonding-strength bimetallic layered composite material.

[0021] The beneficial effects of the present invention are:

[0022] Compared with not using an intermediate layer material, the present invention uses an Fe / V composite intermediate layer material to reduce the interface residual stress and effectively avoid the formation of malignant brittle interlayer compounds. The interface bonding strength of the titanium alloy / hard alloy composite plate is high, with a strength of at least 120 MPa.

[0023] Furthermore, the cemented carbide / titanium alloy bimetallic layered composite material prepared by hot pressing and diffusion compounding of the present invention has good strength, toughness and plasticity as well as low density and excellent wear resistance.

[0024] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0026] Figure 1 Schematic diagram of sample stacking in the hot pressing and diffusion compounding process in the embodiment;

[0027] Figure 2 Schematic diagram of the interface structure of TA15 titanium alloy / YG8 cemented carbide composite plate in the embodiment.

[0028] Reference numerals: 1 - tungsten-cobalt cemented carbide; 2 - iron foil; 3 - vanadium foil; 4 - titanium alloy. DETAILED DESCRIPTION

[0029] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0030] Among them, the accompanying drawings are only for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the dimensions of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the accompanying drawings.

[0031] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "back", etc. indicating directions or positional relationships, they are based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0032] See also Figure 1 , is a preparation process of titanium alloy / hard alloy composite material with high bonding strength. The specific preparation process is as follows:

[0033] Step 1. Raw material preparation: Prepare raw materials such as titanium alloy (TA15) and tungsten-cobalt cemented carbide (YG8), iron foil and vanadium foil intermediate layers using wire cutting method;

[0034] 1) The surface treatment process of TA15 titanium alloy is as follows: one surface of the titanium alloy is polished with 180#, 600#, 1200#, 2000# and / or 3000# diamond sandpaper to remove wire cutting marks and oxide layer on the surface of the sample. After the surface is polished to be smooth and without obvious oxide layer, it is cleaned with alcohol and blown dry. The sample is pickled with a chemical etchant (V(HF):V(HNO3):V(H2O)=3:9:40), cleaned and blown dry for later use.

[0035] 2) The surface treatment process of YG8 tungsten-cobalt cemented carbide is as follows: use 180#, 600#, 1200#, 2000# and 3000# diamond sandpaper to polish one surface of the cemented carbide to remove the wire cutting marks and oxide layer on the surface of the sample until the surface of the cemented carbide is bright and free of oxide layer. After cleaning with alcohol, blow dry and set aside.

[0036] 3) The surface treatment process of iron foil and vanadium foil is as follows: use 600# diamond sandpaper to polish the surface of the foil to remove the oxide layer and wire cutting marks, and then perform ultrasonic cleaning, rinse with alcohol and blow dry for use.

[0037] Step 2. Material assembly: a layer of 2mm tungsten-cobalt carbide, a layer of 0.05mm iron foil, a layer of 0.05mm vanadium foil, a layer of 16mm TA15 titanium alloy, the sample diameter is 38.5mm, the sample stacking diagram is as follows Figure 1 shown.

[0038] Step 3. Hot pressing diffusion composite: A hot pressing diffusion composite test is carried out in a vacuum hot pressing sintering furnace in a vacuum environment (or inert atmosphere) at a temperature of 940°C, a pressing pressure of 10 MPa, and a holding time of 60 min. After cooling in the furnace, a high bonding strength titanium alloy / hard alloy bimetallic layered composite material containing an intermediate layer is obtained, which is recorded as TA15 / (V+Fe) / YG8.

[0039] In addition, for comparison, the same TA15 titanium alloy and YG8 cemented carbide (with the same geometric dimensions) were used to prepare a titanium alloy / cemented carbide bimetallic layered composite material without an intermediate layer material under the same hot pressing and diffusion composite conditions, which was recorded as TA15 / YG8.

[0040] Small specimens (5 mm wide × 10 mm long) were cut from the prepared TA15 / (V+Fe) / YG8 and TA15 / YG8 materials to observe the microstructure near the interface and test the shear strength.

[0041] like Figure 2 As shown in the figure, the interface organization diagram of TA15 titanium alloy / YG8 cemented carbide composite plate, wherein Figure (a) is without intermediate layer (TA15 / YG8), Figure (b) is TA15 / (V+Fe) / YG8 (V side) containing Fe / V intermediate layer, and Figure (c) is Fe / V intermediate layer (Fe side); Figure 2 It can be seen that the sample without an intermediate layer (TA15 / YG8) has cracks at the interface, while the sample containing an Fe / V intermediate layer (TA15 / (V+Fe) / YG8) has good interface bonding and no cracks. In addition, through experimental statistics, it was found that most samples without an intermediate layer (TA15 / YG8) experienced interface cracking during the cutting of small samples. Even for samples without cracking, their interface shear strength was around 10 MPa, and the interface bonding strength was low. For samples containing an Fe / V intermediate layer (TA15 / (V+Fe) / YG8), the interface bonding strength was much higher than that of samples without an intermediate layer, all above 120 MPa, and the highest reached 170 MPa. In addition, the room temperature impact toughness (217J-261J) of the TA15 / (V+Fe) / YG8 composite plate with high interface shear strength was much higher than that of the separate TA15 titanium alloy (36J-53J) and YG8 cemented carbide (5J-7J), showing good comprehensive performance.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all be included in the scope of the claims of the present invention.

Claims

1. A process for preparing a high-bonding-strength bimetallic layered composite material, characterized in that: The following steps are involved: S1. Material preparation: cutting titanium alloy and cemented carbide as raw materials, cutting iron foil and vanadium foil as intermediate layer materials, and performing surface treatment on the raw materials and intermediate layer materials respectively; S2. stacking the raw materials obtained after surface treatment and the intermediate layer materials in the order of cemented carbide / iron foil / vanadium foil / titanium alloy to form a composite blank to be composited; S3. The composite blank is placed in a hot pressing furnace for hot pressing and diffusion compounding. After the hot pressing and diffusion compounding is completed, the blank is taken out after cooling to room temperature in the furnace to prepare a titanium alloy / hard alloy bimetallic layered composite material with high bonding strength.

2. The process for preparing the high bonding strength bimetallic layered composite material according to claim 1, wherein: The iron foil is industrial pure iron, and the vanadium foil is industrial pure vanadium.

3. The process for preparing the high bonding strength bimetallic layered composite material according to claim 1, wherein: In step S1, the process of surface treatment of the titanium alloy in the raw material is as follows: the surface of the titanium alloy used for compounding is polished with sandpaper to remove the cutting marks and oxide layer on the polished surface, and after ensuring that there is no oxide layer on the polished surface, it is cleaned with alcohol and blown dry, and then the cut titanium alloy is pickled with a chemical corrosive agent, and then blown dry for use after cleaning.

4. The process for preparing the high bonding strength bimetallic layered composite material according to claim 1, characterized in that: In step S1, the surface treatment process of the cemented carbide in the raw material is as follows: grinding the surface of the cemented carbide for composite with diamond sandpaper to remove cutting marks and oxide layer on the ground surface of the cemented carbide, cleaning it with alcohol and then drying it for later use.

5. The process for preparing the high bonding strength bimetallic layered composite material according to claim 1, characterized in that: In step S1, the surface treatment process of the iron foil and the vanadium foil is as follows: the surfaces of the iron foil and the vanadium foil used for the composite are polished with sandpaper to remove the oxide layer, the cutting marks and the oxide layer on the polished surfaces of the iron foil and the vanadium foil are removed, and then ultrasonic cleaning is performed, and then rinsed with alcohol and blown dry for use.

6. The process for preparing the high bonding strength bimetallic layered composite material according to claim 1, wherein: In step S3, the temperature of the hot pressing diffusion composite is 850° C. to 950° C., the pressing pressure is 10 to 20 MPa, and the holding time is 40 to 60 minutes.

7. The process for preparing the high bonding strength bimetallic layered composite material according to claim 6, characterized in that: The hot pressing furnace is in a vacuum environment or an inert atmosphere to prevent oxidation of the raw materials and the intermediate layer materials.

8. A high bonding strength bimetallic layered composite material, characterized by: The invention relates to a titanium alloy / hard alloy bimetallic layered composite material with high bonding strength prepared by the preparation process of the bimetallic layered composite material with high bonding strength described in any one of claims 1 to 7.

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