阅读说明：本技术 一种高强镁合金挤压型材及其制造方法 (High-strength magnesium alloy extruded section and manufacturing method thereof ) 是由 唐伟能 徐世伟 谢玉 王成全 于 2020-06-23 设计创作，主要内容包括：本发明公开了一种高强镁合金挤压型材,其除了Mg以外还含有质量百分比如下的下述化学元素：Gd：6.5-9.5％；Y：1.5-4.0％；Zn：0.02-1.0％；Zr：0.01-0.5％。相应地,本发明还公开了上述高强镁合金挤压型材的制造方法,其包括步骤：制得挤压锭；基于有限元模拟软件确定挤压锭在各个方向上的温度分布；按照所述温度分布采用感应加热系统对挤压锭进行加热；将经过加热的挤压锭立即放置于经过预热的挤压筒和挤压模具中进行挤压。本发明所述的高强镁合金挤压型材拥有良好的组织性能均匀性,性能优异且产品质量较高,具有良好的推广前景和应用价值。(The invention discloses a high-strength magnesium alloy extruded section, which contains the following chemical elements in percentage by mass in addition to Mg: gd: 6.5 to 9.5 percent; y: 1.5 to 4.0 percent; zn: 0.02-1.0%; zr: 0.01 to 0.5 percent. Correspondingly, the invention also discloses a manufacturing method of the high-strength magnesium alloy extruded section, which comprises the following steps: preparing an extrusion ingot; determining the temperature distribution of the extruded ingot in each direction based on finite element simulation software; heating the extruded ingot by adopting an induction heating system according to the temperature distribution; the heated extrusion ingot is immediately placed in a preheated extrusion barrel and extrusion die for extrusion. The high-strength magnesium alloy extruded section provided by the invention has the advantages of good uniformity of structural properties, excellent performance, higher product quality, good popularization prospect and good application value.)

1. The high-strength magnesium alloy extruded section is characterized by also comprising the following chemical elements in percentage by mass in addition to Mg:

Gd：6.5-9.5％；

Y：1.5-4.0％；

Zn：0.02-1.0％；

Zr：0.01-0.5％。

2. the high-strength magnesium alloy extruded profile according to claim 1, wherein the mass percentages of the chemical elements are as follows:

Gd：6.5-9.5％；

Y：1.5-4.0％；

Zn：0.02-1.0％；

Zr：0.01-0.5％；

the balance being Mg and other unavoidable impurity elements.

3. The high-strength magnesium alloy extruded profile according to claim 1 or 2, wherein the chemical elements in percentage by mass satisfy at least one of the following:

Gd：7.0-8.5％；

Y：3.5-4.0％；

Zn：0.2-0.6％；

Zr：0.2-0.4％。

4. a high strength magnesium alloy extruded profile according to claim 1 or 2, wherein the structure is uniform and the average grain size is 8 to 15 μm.

5. The high-strength magnesium alloy extruded profile as claimed in claim 1 or 2, wherein the yield strength is 180-260MPa, the tensile strength is 270-320MPa, and the elongation is greater than or equal to 10%.

6. The method for manufacturing a high-strength magnesium alloy extruded profile according to any one of claims 1 to 5, comprising the steps of:

preparing an extrusion ingot;

determining the temperature distribution of the extruded ingot in each direction based on finite element simulation software;

heating the extruded ingot by adopting an induction heating system according to the temperature distribution;

the heated extrusion ingot is immediately placed in a preheated extrusion barrel and extrusion die for extrusion.

7. The method of claim 6, wherein the extrusion barrel is preheated to 300-500 ℃; and/or preheating the extrusion die to 300-.

8. The method of claim 6, wherein the extrusion ram speed during extrusion is 5 to 50 mm/s.

9. The method of manufacture of claim 6, wherein the induction heating system comprises:

a radial induction heating element that heats the extrusion ingot in a radial direction of the extrusion ingot;

an axial induction heating element that heats the extrusion ingot along an axial direction of the extrusion ingot;

a micro-area induction heating element for supplementing heat to the extrusion ingot;

and the controller is respectively connected with the radial induction heating element, the axial induction heating element and the micro-area induction heating element so as to control the radial induction heating element, the axial induction heating element and the micro-area induction heating element to heat the extruded ingot according to the temperature distribution.

10. The method of claim 9, wherein the radial induction heating element, the axial induction heating element, and the micro-zone induction heating element each have an infrared temperature measuring device to detect the temperature of the heated zone of the extruded ingot in real time.

11. The method of claim 6, wherein the extruded ingot is heated to 260 ℃ and 460 ℃.

Technical Field

The invention relates to an extruded section and a manufacturing method thereof, in particular to a magnesium alloy extruded section and a manufacturing method thereof.

Background

The magnesium alloy material has the advantages of low density, high specific strength, good damping and shock absorption, good machining performance, good electromagnetic shielding performance, easy recycling and the like, and is also called as a green engineering structural material in the 21 st century. The magnesium alloy has wide application prospects in the aspects of aerospace, rail transit, automobile materials, 3C industry light weight design and the like, the magnesite reserves of China are the first place in the world, the magnesium resource reserves are rich, and in order to fully exert the resource advantages of China, the industry development is expected to be further led through the magnesium alloy field.

In the process of preparing the metal section, the hot extrusion process is a key link of the process of preparing the section, and generally comprises heating before extrusion, heat preservation in the extrusion process, control of process parameters in the extrusion process and cooling after extrusion. The conventional hot extrusion heating generally adopts uniform temperature extrusion, namely the temperature of the inner surface and the temperature of the outer surface are uniform when an extrusion billet is discharged from a furnace, and air cooling is usually adopted after extrusion. Therefore, the structure and the performance of the extruded section produced by the conventional hot extrusion method at different positions such as the inner surface and the outer surface have more remarkable non-uniformity. The thicker the wall thickness of the extruded section, the more obvious the radial tissue nonuniformity is; the longer the extruded ingot is, the more pronounced the structural inhomogeneity before and after the length direction thereof is. It should be noted that magnesium alloy is difficult to deform, the uniformity of the extruded section is poor, the surface quality is difficult to control, and the straightness and the twisting degree are difficult to guarantee.

In the extrusion deformation process of the magnesium alloy, the temperature value distribution of the material in the extrusion process needs to be well controlled, and fine temperature control extrusion is carried out, so that good surface quality, texture uniformity and mechanical property uniformity can be obtained. Accordingly, how to accurately control the processing temperature and the temperature distribution of the hot extrusion billet has a crucial influence on the improvement of the structural property uniformity of the section and the length direction of the extruded profile.

In the process of extruding the magnesium alloy section, as the shape of the outlet of the die is different according to the size of a specific section, the temperature of the extruded section at the extruding outlet depends on the temperature of the preheated ingot, the heat preservation temperature of an extruding cylinder in the extruding process and the temperature rise caused by the heat generation of friction with the die in the extruding process, and the forming temperature of the extruded section is finally influenced by the comprehensive balance of the three factors. Among them, the temperature distribution of the ingot itself has an important determining role. Therefore, the method has important significance for accurate temperature control of the ingot.

At present, in the prior art, the billet is mainly heated by methods such as gas medium furnace heating, resistance furnace heating, induction furnace heating and the like. When heating a magnesium alloy deformed ingot, the ingot is generally placed in a hearth of a furnace to be heated integrally.

However, when the heating method of the medium furnace is adopted, the medium furnace is heated by gas combustion, and the combustion temperature distribution is not accurately controlled, so that the method is not suitable for magnesium alloy. Correspondingly, when the resistance furnace is adopted for heating, the heating efficiency of the resistance furnace is lower, the heating time is longer, the continuous and quick production is not facilitated, the instant and accurate control on the temperature of the magnesium alloy extrusion billet is difficult to realize, and the tissue of the whole billet is not uniform enough.

For example: chinese patent publication No. CN2902495Y, published as 5/23/2007, entitled "a rolling apparatus for producing magnesium alloy strip coils", discloses a method for ensuring smooth rolling process by placing a roll and a magnesium alloy ingot in a heating and heat-insulating box using a heating and heat-insulating apparatus. The method of placing both the rolls and the billets in the furnace is not conducive to processing operations and field observations, and also presents major difficulties in maintaining the equipment, and the overall heating lacks measures and means for adjusting the temperature distribution of the deformed billets.

Correspondingly, when the deformed billet is heated by adopting an induction heating mode, the integral heating can be realized, namely the whole billet is placed into a large-scale induction heating coil and can be integrally heated to a set temperature value. However, in the preheating stage of the deformed ingot, although relatively uniform microstructure uniformity can be obtained by overall heating, different deformation amounts at different parts in the deformation process inevitably lead to different recrystallization degrees of the material, so that the microstructure difference of the deformed material is huge, and obviously, the mechanical properties of the prepared material and parts thereof are huge.

Since the temperature distribution of the deformed blank greatly affects the uniformity of the structure after extrusion, rolling and other processing, there are few cases that the gradient heating, namely water cooling or air cooling, is adopted in combination with induction heating, is adopted, so that temperature gradients are formed at the front end and the rear end of the magnesium alloy extruded ingot, and the adjustment of the extrusion temperature at the front end and the rear end in the extrusion process is facilitated, and the desired material characteristics are obtained.

For example: chinese patent publication No. CN201433228Y, published as 3/31/2010, entitled "a gradient induction heating furnace for aluminum alloy tube and bar" discloses a method for realizing gradient induction heating of an aluminum alloy tube and bar by using an induction coil, which realizes a temperature gradient of a front section and a rear section of an aluminum bar by extruding a blank bar through a heating coil and a two-section inductor of a temperature compensation coil.

Another example is: chinese patent document No. CN106676436A, published as 2017, 5, month and 17, entitled "a heat treatment furnace and heat treatment method for realizing temperature gradient distribution of extruded billet" discloses a heat treatment method combining gas heating, air cooling and electric induction heating, which realizes temperature gradient distribution heating of axially head-to-tail bottom and radially outer high inner bottom of an extruded billet. However, it should be noted that the above patent technologies simply achieve a certain temperature gradient in the axial and radial directions of the extrusion ingot, and thus the structural uniformity of the extruded profile still needs to be improved.

In general, the temperature distribution of the extruded magnesium alloy profile in the circumferential direction and the radial length direction is strictly required by the process of extruding the profile from the extrusion ingot, and the temperature distribution of the extrusion billet has a great influence on the structural uniformity of the extruded profile.

For simple shape profiles, some of the above techniques, although achieving a temperature gradient in the axial radial direction as described above, lack of regulatory objectives due to such temperature gradient achievement, do not necessarily provide benefits for the uniformity of temperature and texture properties of the final profile, particularly lack of targeted guidance for the effect of a particular profile shape dimension on temperature requirements. Accordingly, even if such a temperature gradient exists in the extruded billet, the temperature field will vary significantly during the extrusion process, due to the influence of the holding temperature of the extrusion barrel itself, after the billet enters the extrusion barrel of the hot extrusion process, and the billet will tend to be reheated as the extrusion time progresses slowly. Therefore, how to self-adaptively customize the temperature distribution of the extrusion ingot and realize temperature-controlled deformation extrusion under the condition of controllable temperature subareas is a key technology for restricting the improvement of the performance uniformity of the magnesium alloy extrusion structure at present.

In summary, in view of the defects and shortcomings commonly existing in the prior art, it is desirable to obtain a high-strength magnesium alloy extruded profile and a manufacturing method thereof, the manufacturing method of the high-strength magnesium alloy extruded profile can smoothly realize temperature-controlled extrusion in the extrusion process of a magnesium alloy extruded ingot, and the high-strength magnesium alloy extruded profile with higher uniformity of structural properties can be obtained.

Disclosure of Invention

One of the purposes of the invention is to provide a high-strength magnesium alloy extruded section which has good structural property uniformity, excellent performance, higher product quality, good popularization prospect and good application value.

In order to achieve the purpose, the invention provides a high-strength magnesium alloy extruded section, which contains the following chemical elements in percentage by mass in addition to Mg:

Gd：6.5-9.5％；

Y：1.5-4.0％；

Zn：0.02-1.0％；

Zr：0.01-0.5％。

further, in the high-strength magnesium alloy extruded section bar of the present invention, the mass percentages of the chemical elements are as follows:

Gd：6.5-9.5％；

Y：1.5-4.0％；

Zn：0.02-1.0％；

Zr：0.01-0.5％；

the balance being Mg and other unavoidable impurity elements.

In the high-strength magnesium alloy extruded section bar, the design principle of each chemical element is as follows:

gd: in the high-strength magnesium alloy extrusion section bar, Gd element is an important alloying element, has larger solid solubility in the magnesium alloy, and can improve the room temperature, high temperature strength and creep resistance of the magnesium alloy by utilizing the solid solution strengthening function of the Gd element and the strengthening function of a rare earth compound MgGd relative to a grain boundary after being added. However, it should be noted that when the content of Gd element in the magnesium alloy is too high, a large amount of eutectic phase is precipitated at grain boundaries, which lowers plasticity, not only increases alloy density significantly, but also increases production cost. Therefore, the mass percentage of Gd is controlled to be between 6.5 and 9.5 percent in the high-strength magnesium alloy extruded section.

In some preferred embodiments, the mass percentage of Gd may be controlled between 7.0-8.5% for better efficacy.

Y: in the high-strength magnesium alloy extrusion section, the Y element has higher solid solubility in the magnesium alloy, and can play a role in solid solution strengthening after being added, and precipitate a rare earth compound MgGdY phase to strengthen a crystal boundary, so that the mechanical strength and the creep resistance of the magnesium alloy are improved. However, it should be noted that too high content of Y element in magnesium alloy will precipitate on grain boundary in large amount, resulting in reduced plasticity of the material. Therefore, the mass percent of Y in the high-strength magnesium alloy extruded section is controlled to be between 1.5 and 4.0 percent.

In some preferred embodiments, the mass percentage of Y may be controlled to be between 3.5 and 4.0% for better performance.

Zn: in the high-strength magnesium alloy extrusion section, Zn is used as an important additive element, an MgZn phase is mainly formed in the magnesium alloy to play a role in strengthening, and the MgZnGd phase is precipitated at a crystal boundary when Gd exists, so that the high-strength magnesium alloy extrusion section has better thermal processing stability. However, it should be noted that too high a Zn content (greater than 1%) may result in coarse second phases, which may affect the mechanical properties of the alloy. Therefore, the mass percent of Zn in the high-strength magnesium alloy extruded section is controlled to be between 0.02 and 1.0 percent.

In some preferred embodiments, the mass percentage of Zn can be controlled between 0.2 and 0.6% for better working effect.

Zr: in the high-strength magnesium alloy extruded section, the solid solubility of Zr element in magnesium is less than 1.0%, crystal nucleus refined grains are mainly formed in the alloy, and the plasticity and strength of the alloy are improved. Therefore, the mass percent of Zr in the high-strength magnesium alloy extruded section is controlled to be between 0.01 and 0.5 percent.

In some preferred embodiments, to achieve better performance. The mass percent of Zr can be controlled between 0.2 and 0.4 percent.

Further, in the high-strength magnesium alloy extruded section of the invention, the mass percentages of the chemical elements satisfy at least one of the following:

Gd：7.0-8.5％；

Y：3.5-4.0％；

Zn：0.2-0.6％；

Zr：0.2-0.4％。

furthermore, in the high-strength magnesium alloy extruded section, the structure is uniform, and the average grain size is 8-15 microns.

Furthermore, in the high-strength magnesium alloy extrusion section, the yield strength is 180-260MPa, the tensile strength is 270-320MPa, and the elongation is more than or equal to 10%.

Accordingly, another object of the present invention is to provide a method for manufacturing a high-strength magnesium alloy extruded profile, which can precisely control the temperature distribution of a magnesium alloy extruded ingot through induction heating, and then rapidly perform extrusion processing, thereby achieving more uniform and efficient deformation of the magnesium alloy extruded profile. The yield strength of the high-strength magnesium alloy extrusion section prepared by the preparation method is 180-260MPa, the tensile strength is 270-320MPa, the elongation is more than or equal to 10 percent, and the high-strength magnesium alloy extrusion section has excellent uniformity of structural properties.

In order to achieve the above object, the present invention provides a method for manufacturing the above high-strength magnesium alloy extruded profile, comprising the steps of:

preparing an extrusion ingot;

determining the temperature distribution of the extruded ingot in each direction based on finite element simulation software;

heating the extruded ingot by adopting an induction heating system according to the temperature distribution;

the heated extrusion ingot is immediately placed in a preheated extrusion barrel and extrusion die for extrusion.

The invention provides an induction heating system capable of controlling a magnesium alloy extruded ingot heating temperature zone according to target temperature cloud pictures in a regional distribution manner and an efficient homogeneous extrusion manufacturing method for improving the texture uniformity of a magnesium alloy extruded profile, aiming at the problems that the preheating temperature distribution of an extruded ingot is lack of accurate control at present and the texture uniformity of the extruded profile obtained in the extrusion process is not enough.

In addition, in the manufacturing method, the efficiency of induction heating of the magnesium alloy extruded ingot is relatively high, the heating effect of the magnesium alloy extruded ingot is good, various temperature distribution trends of the extruded ingot can be accurately controlled, and the product quality is favorably improved.

Further, in the manufacturing method of the present invention, the extrusion container is preheated to 300-; and/or preheating the extrusion die to 300-.

Further, in the production method of the present invention, wherein the extrusion ram speed during the extrusion is 5 to 50 mm/s.

In the technical scheme, the speed of the extrusion push rod in the extrusion process is controlled to be 5-50mm/s, so that the temperature field of the extruded billet with the accurately controlled temperature distribution area can be effectively prevented from being obviously changed after the extruded billet stays in the extrusion cylinder. In addition, the invention adopts higher extrusion speed, effectively improves the extrusion efficiency, can reduce the processing cost of the product, lowers the cost price of the product, and is beneficial to expanding the popularization and application range of the magnesium alloy extruded section.

Further, in the manufacturing method of the present invention, the induction heating system includes:

a radial induction heating element that heats the extrusion ingot in a radial direction of the extrusion ingot;

an axial induction heating element that heats the extrusion ingot along an axial direction of the extrusion ingot;

a micro-area induction heating element for supplementing heat to the extrusion ingot;

and the controller is respectively connected with the radial induction heating element, the axial induction heating element and the micro-area induction heating element so as to control the radial induction heating element, the axial induction heating element and the micro-area induction heating element to heat the extruded ingot according to the temperature distribution.

Among the above-mentioned technical scheme, this induction heating system can carry out subregion accuse temperature induction heating to the extrusion spindle, controls the temperature in different regions, obtains the controllable extrusion spindle of temperature zone distribution, satisfies each regional temperature subregion design needs on the extrusion spindle three-dimensional space.

In addition, this induction heating system adopts a plurality of induction heating element heating and micro-district induction heating element to heat in the different regions of axial and footpath of extrusion spindle, can independently adjust to intelligent control is favorable to local temperature regulation, can realize customization complicated temperature area and distribute, improves accuse temperature precision and accuse temperature mesh nature. It should be noted that each induction heating element in the induction heating system can be flexibly selected and combined according to actual conditions, and a plurality of induction heating elements are adopted, so that the induction heating system can be effectively suitable for induction heating treatment of magnesium alloy extruded ingots with complex temperature requirements and different design results, and has good compatibility.

Further, in the manufacturing method of the present invention, the radial induction heating element, the axial induction heating element, and the micro-zone induction heating element all have an infrared temperature measuring device to detect the temperature of the heated zone of the extruded ingot in real time.

Further, in the manufacturing method of the present invention, the extruded ingot is heated to 260-460 ℃.

Compared with the prior art, the high-strength magnesium alloy extruded section and the manufacturing method thereof have the advantages and beneficial effects as follows:

(1) the manufacturing method of the high-strength magnesium alloy extruded section can adopt a plurality of inductors for heating and micro-zone heaters in different areas in each direction of the circumference and the length of the magnesium alloy extruded section for independent adjustment and intelligent control, is beneficial to local temperature adjustment, can realize customized complex temperature area distribution, and effectively improves the temperature control precision and the temperature control purpose.

(2) The induction heating elements of the induction heating system in the manufacturing method of the high-strength magnesium alloy extruded section can be flexibly selected and combined according to actual conditions, and a plurality of induction heating elements are adopted, so that the induction heating system can be suitable for induction heating treatment of high-strength magnesium alloy extruded sections with different design results and complicated temperature requirements, and has better compatibility.

(3) The manufacturing method of the high-strength magnesium alloy extruded section adopts an induction heating mode, has relatively high induction heating efficiency and good heating effect of the magnesium alloy extruded ingot, can accurately control various temperature distribution trends of the extruded ingot, and is favorable for improving the product quality.

(4) The manufacturing method of the high-strength magnesium alloy extruded section can accurately control the temperature of the extruded ingot in a subarea mode, and realizes targeted subarea temperature control of the extruded section in the deformation process.

The high-strength magnesium alloy extruded section provided by the invention can obtain good uniformity of structural properties by reasonable chemical composition design and matching with a specific manufacturing process. The yield strength of the high-strength magnesium alloy extrusion section is 180-260MPa, the tensile strength is 270-320MPa, the elongation is more than or equal to 10%, the performance is excellent, and the product quality is higher.

Drawings

Fig. 1 schematically shows a process flow diagram of a method for manufacturing a high-strength magnesium alloy extruded profile according to an embodiment of the present invention.

Detailed Description

The high-strength magnesium alloy extruded profile and the manufacturing method thereof according to the present invention will be further explained and illustrated with reference to the following specific examples and drawings, but the explanation and illustration should not be construed as an undue limitation on the technical solution of the present invention.

Fig. 1 schematically shows a process flow diagram of a method for manufacturing a high-strength magnesium alloy extruded profile according to an embodiment of the present invention.

As shown in fig. 1, in this embodiment, when manufacturing the high-strength magnesium alloy extruded profile of the present invention, the extrusion die temperature, the extrusion barrel temperature, and the extrusion rod rapid extrusion speed parameter may be optimized and set according to the shape and size of the cross section of the profile to be extruded, and finite element model analysis is performed based on finite element simulation software to optimize and determine the extrusion ingot heating temperature partition parameter. Then, the induction coil of the induction heating system can be controlled to control the temperature in a subarea way to heat the extrusion ingot according to the temperature distribution design requirement, and the die and the extrusion cylinder of the extrusion equipment are preheated and controlled according to the design parameters. And then putting the heated extrusion ingot pair into an extrusion cylinder and an extrusion die to carry out rapid extrusion according to the design value, thereby preparing the extrusion section with high tissue uniformity.

In the manufacturing method of the high-strength magnesium alloy extruded section, the invention provides the induction heating system which can be used for heating the extruded ingot by zone temperature control according to the temperature distribution design requirement. The induction heating system may include: a radial induction heating element, an axial induction heating element, a micro-zone induction heating element, and a controller. The radial induction heating element can heat the extrusion ingot along the radial direction of the extrusion ingot, so that different heating zones of the surface and the core are realized; the axial induction heating element can heat the extrusion ingot along the axial direction of the extrusion ingot, and independently controls the temperature of different surface positions in the length direction of the extrusion ingot by independently controlling the inductors distributed in each area on the length of the extrusion ingot, so as to heat the extrusion ingot to a target temperature; the micro-area induction heating element can be formed by densely distributing a plurality of micro heating coils, so that the heat compensation of the extrusion ingot is realized.

Correspondingly, a controller in the induction heating system can be respectively connected with the radial induction heating element, the axial induction heating element and the micro-area induction heating element, the controller can control uniform acquisition of information and output of control signals, the temperature of each area of the three-dimensional space of the extruded ingot can be controlled and heated, and the extruded ingot with the required controllable temperature distribution in the temperature area can be obtained.

The induction heating system adopts a plurality of induction heating elements for heating and micro-area induction heating elements in different areas in the axial direction and the radial direction of the extrusion ingot, can be independently adjusted, is intelligently controlled, is favorable for local temperature adjustment, can realize customized complex temperature area distribution, and improves the temperature control precision and the temperature control purpose. In addition, it should be noted that each induction heating element in the induction heating system can be flexibly selected and combined according to actual conditions, and a plurality of induction heating elements are adopted, so that the induction heating system can be effectively suitable for induction heating treatment of magnesium alloy extruded ingots with complex temperature requirements and different design results, and has good compatibility.

It should be noted that in some other embodiments, the radial induction heating element, the circumferential induction heating element, and the micro-zone induction heating element may have infrared temperature measuring devices for better implementation. The infrared temperature measuring devices on the heating elements can detect the temperature of each area of the extruded ingot in real time in an infrared temperature measuring mode, temperature data can be sent to the controller, the controller can calculate the heating power required by the area in real time, and the power data is sent to the heating elements to execute heating. In addition, the controller may compare the temperature of the extruded ingot region calculated in real time with the set temperature of the region. If the temperature of the extrusion ingot area is consistent with the set temperature of the area, the heating power is maintained; if the difference value between the temperature distribution of the extrusion ingot area and the set temperature of the area exceeds the maximum set value, the controller can calculate the adjusting parameters of the heating element in the area and send the adjusting parameters to the corresponding induction heating unit for parameter adjustment, the target temperature distribution designed in the process analysis is used as an adjusting basis, and the temperature meets the temperature distribution requirement in the process design, so that the temperature control heating of the extrusion ingot can be effectively realized, and the temperature distribution requirement in the extrusion process of the magnesium alloy extrusion ingot is met.

In addition, it should be noted that, in some other embodiments, the induction heating system of the present invention may further include a position sensor, which may also be connected to the controller in the induction heating system. The position sensor can effectively position the relative position of the extruded ingot, and transmits related data information to the controller, and the induction heating system is also provided with the position sensor, so that the induction heating system can be effectively and conveniently positioned accurately and can heat the extruded ingot.

Examples 1 to 6 and comparative example 1

Table 1 shows the mass percentages of the respective chemical elements in the high-strength magnesium alloy extruded sections of examples 1 to 6 and the magnesium alloy extruded section of comparative example 1.

TABLE 1 (wt%, balance Mg and other unavoidable impurities)

In the present invention, the high strength magnesium alloy extruded profiles of examples 1 to 6 were prepared by the following steps:

step 1: preparing an extrusion ingot according to the chemical element components shown in the table 1;

step 2: according to the shape and the size of the section to be extruded, optimizing and setting the temperature of an extrusion die, the temperature of an extrusion container and the rapid extrusion speed parameter of an extrusion rod, and determining the temperature distribution of an extrusion ingot in each direction based on finite element simulation software;

and step 3: heating the extruded ingot to 260-460 ℃ by adopting an induction heating system according to the temperature distribution, and adjusting and controlling the temperature of different areas to meet the temperature distribution requirement;

and 4, step 4: the heated extrusion ingot is immediately placed in a preheated extrusion barrel and extrusion die for extrusion. Wherein, the extrusion cylinder is controlled to be preheated to 300-500 ℃, and the speed of the extrusion push rod is controlled to be 5-50mm/s in the extrusion process that the extrusion die is preheated to 300-500 ℃.

In the invention, the magnesium alloy extruded section of comparative example 1 is prepared only by a conventional resistance furnace preheating extrusion ingot preheating mode, the extrusion ingot is prepared according to chemical element components shown in table 1, the prepared extrusion ingot is placed in a resistance furnace, the heating temperature is controlled to be 450 ℃, the extrusion ingot is placed in an extrusion cylinder with the preheating temperature of 430 ℃ after being heated for 4 hours, the temperature of a preheating die is 450 ℃, the speed of an extrusion push rod is controlled to be 0.5mm/s for extrusion, and the extruded section is obtained after cooling after extrusion.

Table 2 shows the specific process parameters for the high strength magnesium alloy extruded profiles of examples 1-6.

Table 2.

It should be noted that, since the heating temperature of the extruded ingot in this case is determined according to the temperature distribution of the extruded ingot in each direction, it is represented as a range value in each embodiment in table 3, rather than a conventional point value.

The prepared high-strength magnesium alloy extruded sections of examples 1 to 6 and the magnesium alloy extruded section of comparative example 1 were subjected to various mechanical property tests, and the test results obtained are shown in table 3.

Table 3 shows the results of mechanical property tests of the high-strength magnesium alloy extruded profiles of examples 1 to 6 and the magnesium alloy extruded profile of comparative example 1.

Table 3.

As can be seen from Table 3, compared with comparative example 1, the mechanical properties of the profiles at the front and rear ends of examples 1-6 of the present invention are more uniform, and the yield strengths of examples 1-6 are all between 180-. The high-strength magnesium alloy extruded section of each embodiment has excellent performances, high strength and excellent mechanical property uniformity.

In the present invention, the high strength magnesium alloy extruded profiles of examples 1 and 4 were expressed as mu-shaped profiles, the high strength magnesium alloy extruded profiles of examples 2 and 5 were expressed as mu-shaped profiles, the high strength magnesium alloy extruded profiles of examples 3 and 6 were expressed as T-shaped profiles, and the magnesium alloy extruded profile of comparative example 1 was expressed as T-shaped profile. The microstructures of the cross sections of the profiles of examples 1 to 6 and comparative example 1 were observed, and the results are shown in Table 4.

Table 4 lists the microstructure observation results of the high-strength magnesium alloy extruded sections of examples 1 to 6 and the magnesium alloy extruded section of comparative example 1.

Table 4.

As can be seen from Table 4, the grain size of the surface of the profile of comparative example 1 is significantly fine, the grain size of the center of the T-shaped profile is significantly coarse, the texture grains of the extruded profile obtained from the extrusion ingot are significantly fine at the front section, the average grains are 15 microns, the grain size of the extruded profile at the rear end is relatively large, and the average grains are 20 microns. Compared with the comparative example 1, the grain sizes of the surface and the core of the profile of the high-strength magnesium alloy extruded profile of the examples 1 to 6 are close, the structure of the cross section of the profile is uniform, the average grain size is between 8 and 15 microns, and the high-strength magnesium alloy extruded profile has excellent structure uniformity.

It can be seen from tables 3 and 4 that the magnesium alloy extruded section of comparative example 1 has poor grain uniformity, the uniformity of mechanical properties is also inferior to that of the embodiments of the present invention, and the high strength magnesium alloy extruded sections of embodiments 1 to 6 of the present invention have good uniformity of structural properties.

In conclusion, the high-strength magnesium alloy extruded section provided by the invention can obtain good uniformity of structural properties by reasonable chemical composition design and matching with a specific manufacturing process. The yield strength of the high-strength magnesium alloy extrusion section is 180-260MPa, the tensile strength is 270-320MPa, the elongation is more than or equal to 10%, the performance is excellent, and the product quality is higher.

Correspondingly, the manufacturing method of the high-strength magnesium alloy extruded section can accurately control the temperature of the magnesium alloy extruded ingot in a partition mode, the temperature of the extruded section in a partition mode is controlled in a targeted mode in the deformation process, and after the alloy is extruded by the process, the extruded section is better in structural uniformity, better in material performance and higher in product quality, and has good popularization prospect and application value.

In addition, the combination of the features in the present application is not limited to the combination described in the claims of the present application or the combination described in the embodiments, and all the features described in the present application may be freely combined or combined in any manner unless contradictory to each other.

It should also be noted that the above-mentioned embodiments are only specific examples of the present invention, and it is obvious that the present invention is not limited to the above-mentioned embodiments, and many similar variations are possible. All modifications which would occur to one skilled in the art and which are, therefore, directly derived or suggested from the disclosure herein are deemed to be within the scope of the present invention.