CN116837249A

CN116837249A - Aluminum bronze alloy and preparation method thereof

Info

Publication number: CN116837249A
Application number: CN202310946768.7A
Authority: CN
Inventors: 李甫
Original assignee: Ambok Foshan Metal Co ltd
Current assignee: Ambok Foshan Metal Co ltd
Priority date: 2023-07-31
Filing date: 2023-07-31
Publication date: 2023-10-03

Abstract

The application is applicable to the technical field of alloy materials, and provides an aluminum bronze alloy and a preparation method thereof, wherein the aluminum bronze alloy comprises the following elements in percentage by weight: 12.5-13.5% of aluminum, 4-6% of iron, 4-6% of nickel or 2-3% of cobalt, 2.5-3.5% of manganese and the balance of copper. The aluminum bronze alloy has the as-cast strength of up to 750Mpa, the yield strength of up to 500Mpa, the Brinell hardness HBW of about 300HB, and the lubrication-free friction coefficient of less than 0.4, can be successfully applied to a guiding device of an automobile die, and can be matched with die steel for sliding friction, and has the advantages of no deformation, high strength, good wear resistance and good thermal conductivity; in addition, the phase structure and intermetallic compound are distributed uniformly and reasonably, the alloy matrix retains a large amount of martensite beta phase, and the alloy matrix has a very small amount of harmful phase, and has high comprehensive mechanical property and corrosion resistance.

Description

Aluminum bronze alloy and preparation method thereof

Technical Field

The application belongs to the technical field of alloy materials, and particularly relates to an aluminum bronze alloy and a preparation method thereof.

Background

The binary alloy of copper and aluminum and the multielement alloy added with Fe, mn or Ni are all called aluminum bronze, the aluminum bronze is an alloy which takes aluminum as a main strengthening element and is researched in the beginning of the 20 th century, and the mechanical property is higher than that of brass and tin bronze, and the binary alloy has extremely high corrosion resistance and strength and toughness comparable with steel, so the binary alloy has very wide application. The Cu-Al binary alloy with the aluminum content of 5% -7% can be generally processed by cold working, the aluminum bronze with the aluminum content of more than 7% needs to be processed by hot working, and the aluminum content can be more than 14% for deep drawing dies and wear-resistant occasions. The aluminum content of the common aluminum bronze is 5-12%, and the aluminum bronze is applied to parts with high wear resistance and corrosion resistance, such as gears, shaft sleeves, propellers, pumps, valve bodies, worm gears and the like.

The aluminum bronze is mainly applied to the fields of good mechanical property and wear resistance, is used as a wear-resistant material which is matched with steel and does not adhere, has high mechanical strength, high hardness and wear resistance, and good thermal conductivity, wherein the aluminum bronze with high performance needs to have the characteristics, the high hardness represents the high wear resistance, but the increase of the hardness can lead to the reduction of elongation, the brittleness of the material is increased, and the brittle fracture of the material is further caused. The reduction in hardness ensures that breakage does not occur, but the tensile strength and yield strength are also reduced, the alloy material is easily deformed, and sufficient mechanical strength and wear resistance cannot be ensured. In addition, considering corrosion in the application environment, corrosion cracking is also a mode of material failure, and for high-hardness materials, the widmannstatten structure and martensite beta phase or other hard and brittle phases are more susceptible to corrosion by media, so that the high-hardness material has good oxidation resistance and corrosion resistance and is also a necessary characteristic of excellent alloy.

How to design a high-performance copper alloy, on the premise of ensuring the hardness and wear resistance of the material, how to keep the high material strength without breaking failure and oxidation corrosion aging is a difficult point of copper alloy design, the strength of the aluminum bronze alloy after casting in the market is generally below 600Mpa, the hardness is lower than 150HB, the aluminum bronze alloy is used as a mechanical part or a wear-resistant sliding block, and the special high-strength application requires the participation of additional forging and heat treatment procedures. A part of high-hardness aluminum bronze is used in the deep drawing die market, has high hardness and wear resistance, has the hardness range of 250HB-400HB, but has very poor mechanical property, tensile strength of less than 500Mpa, elongation after fracture of 0 percent, easy occurrence of fracture in the processing process and serious corrosion in the use process.

Disclosure of Invention

The embodiment of the application aims to provide an aluminum bronze alloy, which aims to provide a copper alloy with high comprehensive performance, high strength in a casting state, difficult fracture, excellent wear resistance and corrosion resistance.

The embodiment of the application is realized in such a way that the aluminum bronze alloy comprises the following elements in percentage by weight:

12.5-13.5% of aluminum, 4-6% of iron, 4-6% of nickel or 2-3% of cobalt, 2.5-3.5% of manganese and the balance of copper.

Another object of an embodiment of the present application is a method for manufacturing an aluminum bronze alloy, comprising:

weighing an aluminum raw material, an iron raw material, a nickel/cobalt raw material, a manganese raw material and a copper raw material according to the formula of the aluminum bronze alloy;

sequentially adding an aluminum raw material, an iron raw material, a nickel/cobalt raw material, a manganese raw material and a part of copper raw material into smelting equipment for smelting treatment, and then adding the rest part of copper raw material for continuing smelting treatment to obtain smelting liquid;

casting the smelting liquid by adopting a casting cavity with chilling materials to obtain a casting;

and in the casting cooling process, opening the box and cooling when the casting is cooled to 600-700 ℃ to obtain the casting.

The embodiment of the application provides a quinary aluminum bronze alloy, the as-cast strength of the quinary aluminum bronze alloy is up to 750Mpa, the yield strength of the quinary aluminum bronze alloy can be up to 500Mpa, the Brinell hardness HBW can be up to about 300HB, the lubrication-free friction coefficient is lower than 0.4, the alloy material can be successfully applied to a guiding device of an automobile die, and the alloy material can be matched with die steel to carry out sliding friction, and has the advantages of no deformation, high strength, good wear resistance and good heat conductivity.

In addition, the preparation method of the quinary aluminum bronze alloy provided by the embodiment of the application ensures that the material does not absorb gas by controlling the smelting temperature and adopting a mode of intermediate alloy in the smelting process, and the casting does not have defects such as air holes; in the molding process, improving the properties of the crystallized and solidified structure through a fine grain strengthening technology; and in the post-treatment process of the solidification forming of the casting, in order to obtain martensite beta phase, the casting is opened in a temperature range of 600-700 ℃ for atomization and cooling, so that a matrix structure is obviously strengthened. In addition, the preparation process is formed by casting, does not need to participate in heat treatment, and the obtained alloy material has excellent oxidation corrosion resistance and annealing softening resistance, and the research on a matrix structure by a scanning electron microscope ensures that the phase structure and intermetallic compounds are uniformly and reasonably distributed, and a large amount of martensite beta phase is reserved on the matrix, so that the preparation process prevents eutectoid transformation and greatly reduces the probability of material failure of the alloy.

Drawings

FIG. 1 is a phase structure distribution diagram of an aluminum bronze alloy provided by an embodiment of the present application;

FIG. 2 is a secondary electron image and a back-scattered electron image of an aluminum bronze alloy provided in an embodiment of the present application.

Detailed Description

The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

The embodiment of the application provides a novel aluminum bronze alloy, wherein the strength of a target material after casting is more than 600Mpa, the yield strength is about 500Mpa, the elongation after breaking is more than 2%, and the hardness range is more than 250HB by determining the required performance. Further, a multi-element alloy type and a strengthening phase are selected: in order to ensure that the material can obtain comprehensive mechanical properties and corrosion resistance, a Cu-Al-Fe-Mn-Ni (Co) quinary alloy series is selected. Wherein, the effect of cobalt is stronger than nickel, is twice the effect of Ni in copper, 5 phases and structures, namely an alpha phase, a martensite beta phase, a K phase based on an aluminum-iron compound, a K phase based on a nickel-aluminum compound and a gamma 2 phase, appear after the five-element material series casting, the strengthening phases are researched, the martensite beta phase and the gamma 2 phase are selected as strengthening phases for ensuring the strength and the wear resistance of the material, and the K phase is selected as the guarantee of the toughness and the corrosion resistance of the alloy. Further, the element content range is determined: al is used as a main strengthening element, and under the requirements of the hardness and the strengthening phase, the equivalent weight of the aluminum is more than 12 percent, and in order to ensure that excessive gamma 2 phase does not occur, the upper limit is limited to 13 percent, so that the content of the aluminum is within the composition range: 12% -13% and 2.5% -3.5% of manganese content, thereby ensuring the stability of beta phase. Iron and nickel are used as main forming elements of K phase and guarantee of corrosion resistance, and the component ranges are 4-6%. If cobalt is used instead of nickel, the composition ranges from 2 to 3%. In addition, in order to ensure that the beta phase does not generate eutectoid transformation at 550 ℃ to generate an alpha+K+γ2 eutectoid mixture, the specific implementation process adopts a chilling material and a rapid cooling mode after casting to improve the supercooling degree, reduce the eutectoid structure and the generation of harmful phases, and obtain a large proportion of martensite beta phase.

In an embodiment of the application, the aluminum bronze alloy comprises the following elements in percentage by weight:

Wherein, the tensile strength of the aluminum bronze alloy is more than 650Mpa, the yield strength is more than 470Mpa, the elongation after break is more than 2%, and the Brinell hardness is more than 285HB.

The embodiment of the application provides a preparation method of the aluminum bronze alloy, which is characterized by comprising the following steps:

In the embodiment of the application, after aluminum raw material, iron raw material, nickel/cobalt raw material, manganese raw material and partial copper raw material are sequentially added into smelting equipment to carry out smelting treatment, the rest copper raw material is added to continue smelting treatment, and the step of obtaining smelting liquid comprises the following steps:

adding an aluminum raw material into smelting equipment, sequentially placing an iron raw material and a nickel/cobalt raw material above the aluminum raw material, filling the rest space with a part of copper raw material, smelting until all the raw materials are completely melted into liquid, and adding the rest part of copper raw material for smelting to obtain smelting liquid.

In the embodiment of the application, in the smelting process of alloy materials, smelting equipment adopts an intermediate frequency induction furnace to smelt, and ingredients of target materials are mixed according to the burning loss, the main raw materials of the alloy are electrolytic copper, pure aluminum, low carbon steel, metal manganese and electrolytic nickel/cobalt plates, pure aluminum, low carbon steel, electrolytic nickel/cobalt plates and metal manganese are firstly added in the charging process, partial electrolytic copper is added in the rest part, the smelting temperature can be 1100 ℃, the rest part of electrolytic copper is added after all smelting is carried out, the smelting temperature is lower than 1200 ℃, the ingredients are sampled and measured after all smelting, and degassing refining is started by using dry inert gas such as high-purity argon (99.9%), and after the ingredients and the gas content test before the furnace are qualified, the casting temperature is adjusted to 1180 ℃ for casting.

In the embodiment of the application, a large amount of high-heat-conductivity materials are used as chilling materials in the molding process, a pouring system in a bottom pouring mode is adopted in the pouring molding process of the alloy, a riser is arranged at the top of a casting, and the chilling materials are arranged at the bottom and the side surfaces of the casting.

In the embodiment of the application, in the cooling process after casting pouring, according to the size of a product and the characteristics of a tool, a box is opened in advance for cooling after a riser is solidified for 30-60 min, and the cooling mode is selected for water mist cooling, so that the martensitic transformation of beta phase is accelerated, and the performance of a matrix is enhanced.

According to the preparation method of the aluminum bronze alloy, provided by the embodiment of the application, the defects of no gas absorption of materials, no air holes of castings and the like are avoided by controlling the smelting temperature and adopting a mode of intermediate alloy in the smelting process; in the molding process, improving the properties of the crystallized and solidified structure through a fine grain strengthening technology; and in the post-treatment process of casting solidification forming, in order to obtain martensite beta phase, the casting is opened in a temperature range of 600-700 ℃ for atomization and cooling, so that the matrix structure is obviously strengthened, and the casting is an application of innovative manufacturing technology.

Specific examples of certain embodiments of the application are given below and are not intended to limit the scope of the application.

Example 1: aluminum bronze alloy sheets were produced with dimensions 1500 x 500 x 50mm. Smelting equipment: medium frequency coreless induction furnace. And (3) batching: 12.5% of pure aluminum ingot, 5% of electrolytic nickel plate, 5% of low-carbon steel, 3.3% of manganese metal sheet and the balance of electrolytic copper, and all materials are cut into small pieces as much as possible.

Step 1: firstly adding an aluminum ingot, placing low-carbon steel fragments and small electrolytic nickel plates above the aluminum ingot, placing manganese metal above the aluminum ingot, filling the rest space with electrolytic copper, and charging without leaving gaps as much as possible. Starting smelting, quickly smelting as much as possible, heating to 1100 ℃, keeping the temperature until all the components are completely melted into liquid, adding the rest of electrolytic copper, controlling the smelting temperature to be lower than 1200 ℃, preventing the metal liquid from being sucked, starting sampling, adjusting chemical components, degassing and refining by using dry high-purity argon (99.9%) for 10-20 minutes, waiting for pouring after the components and the detection before the furnace are finished, and controlling the pouring temperature to 1180 ℃.

Step 2: the modeling procedure performed in synchronization is as follows: preparing a casting mould and a necessary pouring port system, selecting graphite blocks as chill, adopting a pouring system in a bottom pouring mode, placing a riser at the top, placing the graphite blocks at the bottom and the side surfaces of the casting, using a 400 x 100 x 80mm graphite block bottom-laying box at the bottom, using a 100 x 50mm standard graphite block at the side surface, using a thickness surface or a width surface of the graphite blocks, using a gap between the graphite blocks of 10-20mm, adopting a furan resin sand molding production process, brushing zircon powder coating, drying, cleaning a box assembly and waiting for pouring.

Step 3: after casting, after the riser is solidified for 30min, cleaning one corner of the casting body, detecting the temperature of the casting body by using an infrared thermometer, cooling to 600-700 ℃, opening the box, quickly cleaning floating sand on the surface, and quickly atomizing and cooling by using water mist until the temperature of the casting body is lower than 300 ℃. And (5) cutting, pouring, riser system and processing after cooling to room temperature.

Example 2: aluminum bronze alloy sheets were produced with dimensions 1500 x 500 x 70mm. Smelting equipment: medium frequency coreless induction furnace. And (3) batching: 13% of pure aluminum ingot, 4.5% of electrolytic nickel plate, 4.5% of low-carbon steel, 2.5% of manganese metal sheet and the balance of electrolytic copper, and all materials are cut into small pieces as much as possible.

Step 2: the modeling procedure performed in synchronization is as follows: preparing a casting mould and a necessary casting head system, selecting graphite blocks as chill, adopting a bottom pouring type casting system, placing a riser at the top, placing the graphite blocks at the bottom and the side surfaces of the casting, paving a bottom box with the graphite blocks of 400 x 100 x 80mm at the bottom, using the graphite blocks of 50mm specification at the side surfaces of 100 x 50mm, using the thickness surface or the width surface of the graphite blocks, forming a gap of 10-20mm between the graphite blocks, adopting a furan resin sand molding production process, brushing zircon powder coating, drying, cleaning a box assembly and waiting for casting.

Example 3: producing aluminum bronze alloy plates with the size of 1500 x 500 x 100mm, and smelting equipment: medium frequency coreless induction furnace. And (3) batching: 12.6% of pure aluminum ingot, 5.5% of low-carbon steel sheet, 4.5% of electrolytic nickel plate, 3.5% of manganese metal and the balance of electrolytic copper, and all materials are cut into small pieces as much as possible.

Example 4: producing aluminum bronze alloy plates with the size of 1500 x 500 x 100mm, and smelting equipment: medium frequency coreless induction furnace. And (3) batching: 12.7% of pure aluminum ingot, 5.5% of low-carbon steel sheet, 5.5% of electrolytic nickel plate, 2.8% of manganese metal and the balance of electrolytic copper, and all materials are cut into small pieces as much as possible.

Example 5: producing aluminum bronze alloy plates with the size of 1500 x 500 x 100mm, and smelting equipment: medium frequency coreless induction furnace. And (3) batching: 13% of pure aluminum ingot and low-carbon steel sheet: 6% of electrolytic nickel plate, 6% of metal manganese: 3.2% electrolytic copper, the remainder, all material was cut into small pieces as much as possible.

Example 6: producing aluminum bronze alloy plates with the size of 1500 x 500 x 100mm, and smelting equipment: medium frequency coreless induction furnace. And (3) batching: 13% of pure aluminum ingot, 5% of low-carbon steel sheet, 2.5% of electrolytic cobalt, 3.2% of manganese metal and the balance of electrolytic copper, and cutting all materials into small pieces as much as possible.

Step 1: firstly adding an aluminum ingot, placing low-carbon steel fragments and small electrolytic cobalt above the aluminum ingot, placing manganese metal above the aluminum ingot, filling the rest space with electrolytic copper, and charging without leaving gaps as much as possible. Starting smelting, quickly smelting as much as possible, heating to 1100 ℃, keeping the temperature until all the components are completely melted into liquid, adding the rest of electrolytic copper, controlling the smelting temperature to be lower than 1200 ℃, preventing the metal liquid from being sucked, starting sampling, adjusting chemical components, degassing and refining by using dry high-purity argon (99.9%) for 10-20 minutes, waiting for pouring after the components and the detection before the furnace are finished, and controlling the pouring temperature to 1180 ℃.

The aluminum bronze alloy prepared by the embodiment of the application can be successfully applied to a die of an automobile bumper and used as a guiding wear-resistant column, and has the functions of sliding friction with die steel, low friction coefficient, good wear resistance and mechanical strength which is indispensable for sliding.

If the well-known domestic related research is used for the high-temperature shape memory alloy CuAlMn or CuAlFeMn series, the copper-based memory alloy is used as the memory metal, the mechanical property of the copper-based memory metal is poor, the crystal boundary is easy to crack, the component range is too large or undefined, and the corresponding mechanical property is almost uncertain and can not be applied to the wear-resistant field; the most common Cu-Al-Fe-Mn type quaternary alloy on the market is C95900 of the American CDA brand, and the specific components are Cu 80-85%, al 12-13.5%, fe3-5% and Mn0-1.5%.

The aluminum bronze alloys prepared in examples 1-6 above were subjected to comparative testing of mechanical properties with respect to U.S. C95900 copper alloys of the same application and hardness levels, the test results being shown in Table 1 below. All of the following alloy materials were based on as-cast testing and comparison, and the corresponding test data for the aluminum bronze alloys prepared in examples 1-6 were measured by a metal universal tensile tester, and the C95900 performance data was the American CDA standard performance.

TABLE 1

In summary, as can be seen from table 1, the strength of the aluminum bronze alloy material produced by the product formulation and the manufacturing process provided by the examples of the present application is improved by at least 30% compared with the strength of the U.S. C95900 alloy material at the same hardness level, and the elongation after break is improved by at least 2 times.

Table 2 below shows the performance data of national standard aluminum bronze alloys based on GB/T1176-2013 cast copper and copper alloys, in the cast national standard, the best performance is ZCUAl8Mn14Fe3Ni2 alloy, the strength reaches 735Mpa, but the yield strength is only 280Mpa, and the hardness is 170HB; other alloys have hardness below 170HBW after casting, low hardness does not provide sufficient wear resistance, none of the national standard alloys has a brinell hardness above 250HBW, and the tensile strength reaches 700Mpa with a yield strength approaching 500 Mpa.

TABLE 2

Further, in order to more clearly show the underlying logic of the outstanding performance of the aluminum bronze alloy of the application, metallographic analysis is carried out on the aluminum bronze alloy product prepared in the embodiment 1 of the application, and a multifunctional field emission scanning electron microscope of the Thermo Fisher of the United states is utilized to observe the structure of the alloy, as shown in figure 1, each phase and component are fused uniformly, wherein a large-size beta phase is taken as a hard particle, if the alloy is regarded as concrete, the beta phase is similar to stones in reinforced concrete, the strength and the wear resistance of the application of the alloy are provided, the similar weathering white spots dispersed on the beta phase are K5 phases based on NiAl particles, the strong oxidation resistance and corrosion resistance are ensured, the beta phase is not corroded in the daily common application environment, the alpha phase of the matrix is dispersed and dispersed K4 particles (based on Fe3 Al) are interspersed, and the very small K4 particles ensure that the alpha phase has strong toughness and a certain elongation after fracture. The detrimental phases which are unavoidable in the production of the alloy, which can cause the age at break of the material or affect other properties, are the Wittig-structure alpha phase and gamma 2 phase, the ratio of which is very small and almost negligible, as can be seen in FIG. 1. The results on the microstructure observed by scanning electron microscopy support the performance of the alloy. From the back-scattering electron photograph of each element in FIG. 2, the surface elements of the Cu-Al-Fe-Ni-Mn alloy are uniformly and finely distributed, and no serious segregation phenomenon exists. The formula has definite component range, and the special manufacturing process achieves that the alloy has excellent comprehensive mechanical properties of strength, hardness, wear resistance and corrosion resistance in the casting state, is applied in the actual production process, and has no products of the same type at home and abroad.

The foregoing examples illustrate only a few embodiments of the application and are described in detail herein without thereby limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

The foregoing description of the preferred embodiments of the application is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the application.

Claims

1. An aluminum bronze alloy, characterized by comprising the following elements in percentage by weight:

2. The aluminum bronze alloy according to claim 1, wherein the microstructure of the aluminum bronze alloy is comprised of an alpha phase, a martensitic beta phase, a K phase based on an aluminum iron compound, a K phase based on a nickel aluminum compound, and a gamma 2 phase.

3. The aluminum bronze alloy according to claim 2, wherein the nickel aluminum compound-based K phase is dispersed over the martensitic beta phase and the alpha phase is interspersed with the dispersed aluminum iron compound-based K phase.

4. The aluminum bronze alloy according to claim 1, wherein the aluminum bronze alloy has a tensile strength of > 650Mpa, a yield strength of > 470Mpa, an elongation after break of > 2% and a brinell hardness of > 285HB.

5. The aluminum bronze alloy according to claim 1, wherein the aluminum bronze alloy has an as-cast strength of up to 750Mpa, a yield strength of up to 500Mpa, a brinell hardness HBW of up to 300HB, and a non-lubricated coefficient of friction of less than 0.4.

6. A method of producing an aluminum bronze alloy, comprising:

weighing an aluminum raw material, an iron raw material, a nickel/cobalt raw material, a manganese raw material and a copper raw material according to the formula of the aluminum bronze alloy as claimed in claim 1;

7. The method for producing an aluminum bronze alloy according to claim 6, wherein in the step of casting the molten metal using the casting cavity with the chill material, a bottom casting type casting system is used, a riser is placed on the top of the casting, and the chill material is placed on the bottom and the side surfaces of the casting.

8. The method for producing an aluminum bronze alloy according to claim 6, wherein in the cooling process of the casting, the cooling process of opening the box is performed when the aluminum bronze casting is cooled to 600 to 700 ℃, and a water mist cooling process is used to accelerate the martensitic transformation of the beta phase.

9. The method for preparing aluminum bronze alloy according to claim 6, wherein the step of adding aluminum raw material, iron raw material, nickel/cobalt raw material, manganese raw material and part of copper raw material in sequence in smelting equipment to perform smelting treatment, and then adding the rest of copper raw material to continue smelting treatment to obtain smelting liquid comprises the following steps:

10. The method for producing an aluminum bronze alloy according to claim 6, characterized in that the melting temperature is 1100 to 1200 ℃.