CN114231807A

CN114231807A - Aluminum alloy material applied to heat exchanger and preparation method thereof

Info

Publication number: CN114231807A
Application number: CN202111539150.6A
Authority: CN
Inventors: 管保清
Original assignee: Jiangsu Shengxiang Light Alloy Technology Co ltd
Current assignee: Jiangsu Shengxiang Light Alloy Technology Co ltd
Priority date: 2021-12-15
Filing date: 2021-12-15
Publication date: 2022-03-25

Abstract

The invention relates to the technical field of aluminum alloy preparation, in particular to an aluminum alloy material applied to a heat exchanger and a preparation method thereof. According to the invention, Sb is added, antimony is mainly used as a modifier in the cast aluminum alloy, and AISb compounds can be formed when antimony is added into aluminum, the melting point of the compounds can reach 1000 ℃, the eutectic structure of the aluminum alloy is continuously refined along with the increase of the addition of Sb in the alloy, the nucleation and growth capacity of an alpha-AI phase can be improved when the aluminum alloy is eutectic and solidified, and the plasticity and the elongation of the aluminum alloy are improved. The La (lanthanum) element can form refractory active metal compounds with the aluminum alloy, and the active metal compounds are dispersed among eutectic structures of the aluminum alloy and firmly combined with the matrix, so that the crystal arrangement of the aluminum alloy is changed, and the strengthening and stabilizing effects are achieved. Meanwhile, the addition of La is also beneficial to refining crystal grains, so that the brittleness of the aluminum alloy material is reduced, and the strength, the corrosion resistance and the thermoplasticity of the aluminum alloy material are further improved.

Description

Aluminum alloy material applied to heat exchanger and preparation method thereof

Technical Field

The invention relates to the technical field of aluminum alloy preparation, in particular to an aluminum alloy material applied to a heat exchanger and a preparation method thereof.

Background

Aluminum alloys are the most widely used class of non-ferrous structural materials in industry and have found a number of applications in the aerospace, automotive, mechanical manufacturing, marine and chemical industries. The aluminum alloy has low density, high strength similar to or superior to that of high-quality steel, good plasticity, excellent electric conductivity, heat conductivity and corrosion resistance, is widely used in industry, and is second to steel in use amount.

However, the existing aluminum alloy has single function, although the existing aluminum alloy has high hardness, the existing aluminum alloy has poor plasticity and poor elongation, and the hardness and the strength cannot have larger breakthrough, so that the application of the aluminum alloy is limited to a certain extent. Therefore, there is a need for an aluminum alloy material that satisfies the high strength requirements and has high toughness.

Disclosure of Invention

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

the invention provides an aluminum alloy material applied to a heat exchanger, which comprises the following components in percentage by mass:

0.25-0.8% of Si, 0.4-0.7% of Fe, 0.1-2% of Cu, 0.1-0.9% of Mn, 0.8-2.8% of Mg, 0.1-0.35% of Cr, 0.1-0.25% of Zn, 0.15-0.2% of Ti, 0.1-0.6% of La, 0.1-0.3% of Sb, less than or equal to 0.15% of impurity elements and 94.55-97.8% of AI.

Further, the La accounts for 0.15-0.25% by mass.

Further, the mass percent of Sb is 0.12-0.25%.

Further, the preparation method of the aluminum alloy material applied to the heat exchanger comprises the following steps:

(1) adding raw material aluminum into a melting furnace, heating to 680-720 ℃, and stirring to enable the aluminum to be melted uniformly to a molten state;

(2) adding 0.25-0.8% of Si, 0.4-0.7% of Fe, 0.1-2% of Cu, 0.1-0.9% of Mn, 0.8-2.8% of Mg, 0.1-0.35% of Cr, 0.1-0.25% of Zn, 0.15-0.2% of Ti, 0.1-0.6% of La, 0.1-0.3% of Sb and less than 0.15% of impurity elements in percentage by mass, and filling nitrogen;

(3) continuously stirring uniformly to an alloy system, and keeping the temperature for 60-100 min;

(4) degassing and refining for 20-40min in a refining furnace by adopting nitrogen and a refining agent, and standing for 30-35min after refining is finished;

(5) casting the aluminum liquid to obtain an aluminum alloy standard aluminum ingot pattern;

(6) stretching, cooling and shaping to obtain the aluminum alloy formed part.

Further, the raw materials in the step (2) comprise the following components in percentage by mass: 0.4-0.65% of Si, 0.5-0.6% of Fe, 0.15-0.18% of Cu, 0.2-0.7% of Mn, 1-2.5% of Mg, 0.15-0.3% of Cr, 0.15-0.2% of Zn, 0.1-0.2% of Ti, 0.12-0.25% of La, 0.15-0.25% of Sb and less than 0.1% of impurity elements.

Further, the impurity elements comprise lead (Pb), tin (Sn) and bismuth (Bi) with the sum of the mass percent of less than or equal to 0.1 percent.

Further, the refining temperature in the refining furnace in the step (4) is 700-.

Further, the casting manner in the step (5) includes pressure casting, gravity casting or extrusion casting.

The invention has the advantages or beneficial effects that:

the Sb element is added into the aluminum alloy provided by the invention, antimony is mainly used as a modifier in the cast aluminum alloy, and the antimony is added into the aluminum to form an AISb compound, the melting point of the compound can reach 1000 ℃, the compound is solid at the aluminum alloy smelting temperature, the eutectic structure of the aluminum alloy is continuously refined along with the increase of the addition of Sb in the aluminum alloy, the nucleation and growth capacity of an alpha-AI phase during eutectic solidification of the aluminum alloy can be improved, and the plasticity and the elongation of the aluminum alloy are improved.

The La (lanthanum) element can form refractory active metal compounds with the aluminum alloy, and the active metal compounds are dispersed among eutectic structures of the aluminum alloy and firmly combined with the matrix to change crystal arrangement of the aluminum alloy, so that the formation of sites which are easily combined with active hydrogen on the crystal surface of the aluminum alloy is inhibited, and the strengthening and stabilizing effects are achieved. Meanwhile, the addition of La is also beneficial to refining crystal grains, so that the brittleness of the aluminum alloy material is reduced, and the strength, the corrosion resistance and the thermoplasticity of the aluminum alloy material are further improved.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application.

It will be understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

The terms "central," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," and the like are used merely to facilitate describing the invention and to simplify the description, and do not indicate or imply that the referenced devices or components must be in a particular orientation, constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

The appearances of the terms first, second, and third, if any, are used for descriptive purposes only and are not intended to be limiting or imply relative importance.

Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The technical solutions in the embodiments of the present invention are described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Thus, the detailed description of the embodiments of the present invention provided below is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the invention without making creative efforts, belong to the protection scope of the invention.

The existing aluminum alloy has single function, although the existing aluminum alloy has high hardness, the existing aluminum alloy has poor plasticity and poor elongation, and the hardness and the strength cannot have greater breakthrough, so that the application of the aluminum alloy is limited to a certain extent. Therefore, there is a need for an aluminum alloy material that satisfies the high strength requirements and has high toughness.

Therefore, the invention provides an aluminum alloy material applied to a heat exchanger, which comprises the following components in percentage by mass:

Preferably, the mass percent of La is 0.15-0.25%.

Preferably, the mass percent of Sb is 0.12-0.25%.

Si (silicon), Fe and Al can form superfine high-temperature stable phase Al (Fe) Si, so that the stability of the aluminum alloy after welding is improved, and the influence brought by Fe and not beneficial to the corrosion resistance of the aluminum alloy is effectively reduced;

fe (iron) can improve the tensile strength, yield limit and heat resistance of the aluminum base and can also improve the plasticity of the alloy;

cu (copper) is a basic strengthening element in aluminum alloys, and forms theta (Al) with aluminum₂Cu) phase and theta phase have the effects of solid solution strengthening and dispersion strengthening, and the tensile strength and the yield strength of the aluminum alloy can be effectively improved by adding 0.1-0.2% of Cu;

mn (manganese) Al-Mn alloys are non-age-hardenable alloys, i.e., non-heat treatable strengthened. Manganese can prevent the recrystallization process of the aluminum alloy, improve the recrystallization temperature and obviously refine recrystallized grains. The recrystallized grains are refined mainly by MnAl₆The compound dispersoids act as a barrier to the growth of recrystallized grains.

The strengthening of aluminum by Mg (magnesium) is evident, with about a rise in tensile strength for each 1% increase in MgThe height is 34 MPa. If less than 1% manganese is added, it is possible to supplement the strengthening effect. Therefore, the magnesium content can be reduced after manganese is added, the hot cracking tendency can be reduced, and in addition, the manganese can also ensure Mg₅Al₈The compound is uniformly precipitated, and the corrosion resistance and the welding performance are improved.

Cr (chromium) in aluminum to form (CrFe) Al₇And (CrMn) Al₁₂The intermetallic compounds hinder the nucleation and growth process of recrystallization, have certain strengthening effect on the alloy, and can also improve the toughness of the alloy and reduce the stress corrosion cracking sensitivity.

Zn (zinc) is added into aluminum independently, the improvement of the strength of the aluminum alloy is very limited under the deformation condition, and stress corrosion cracking and tendency exist simultaneously, so the application of the Zn (zinc) is limited. Adding zinc and magnesium simultaneously into aluminum to form a strengthening phase Mg/Zn₂It has obvious strengthening effect on the alloy.

Ti (titanium) is a commonly used additive element in aluminum alloys and is added in the form of an Al-Ti master alloy. TiAl is formed between titanium and aluminum₂The phase becomes a non-spontaneous core during crystallization, and plays a role in refining a cast structure and a weld structure.

Preferably, the preparation method of the aluminum alloy material applied to the heat exchanger comprises the following steps:

(6) stretching, cooling and shaping to obtain the aluminum alloy formed part.

Preferably, the impurity elements comprise lead (Pb), tin (Sn) and bismuth (Bi) with the sum of the mass percent of less than or equal to 0.1 percent.

Preferably, the refining temperature in the refining furnace in step (4) is 700-.

Preferably, the casting manner in step (5) includes pressure casting, gravity casting or squeeze casting.

Example 1

(1) Adding raw material aluminum into a melting furnace, heating to 700 ℃, and stirring to melt the aluminum uniformly to a molten state;

(2) adding 0.4-0.65% of Si, 0.5-0.6% of Fe, 0.15-0.18% of Cu, 0.2-0.7% of Mn, 1-2.5% of Mg, 0.15-0.3% of Cr, 0.15-0.2% of Zn, 0.1-0.2% of Ti, 0.12-0.25% of La, 0.15-0.25% of Sb and less than 0.1% of impurity elements (lead, tin and bismuth) according to mass percent, and filling nitrogen; the ingredient table is shown in table 1;

(3) continuously stirring uniformly to an alloy system, and keeping the temperature for 80 min;

(4) degassing and refining for 30min in a refining furnace by adding a refining agent into nitrogen at the refining temperature of 720 ℃, and standing for 32min after refining is finished;

(5) carrying out standard-style gravity casting on the aluminum liquid to obtain an aluminum alloy standard aluminum ingot style;

(6) stretching, cooling and shaping to obtain the aluminum alloy formed part.

The aluminium alloys prepared according to the above method were subjected to performance tests, the results of which are shown in table 2.

Example 2

(1) Adding raw material aluminum into a melting furnace, heating to 710 ℃, and stirring to melt the aluminum uniformly to a molten state;

(2) adding Si, Fe, Cu, Mn, Mg, Cr, Zn, Ti, La, Sb and impurity elements (lead, tin and bismuth) according to the mass percent, and filling nitrogen; the ingredient table is shown in table 1;

(3) continuously stirring uniformly to an alloy system, and keeping the temperature for 70 min;

(4) degassing and refining for 25min in a refining furnace by adding a refining agent into nitrogen at the refining temperature of 710 ℃, and standing for 31min after refining is finished;

(6) stretching, cooling and shaping to obtain the aluminum alloy formed part.

Example 3

(1) Adding raw material aluminum into a melting furnace, heating to 720 ℃, and stirring to melt the aluminum uniformly to a molten state;

(3) continuously stirring uniformly to an alloy system, and keeping the temperature for 90 min;

(4) degassing and refining for 40min in a refining furnace by adding a refining agent into nitrogen at the refining temperature of 740 ℃, and standing for 35min after refining is finished;

(6) stretching, cooling and shaping to obtain the aluminum alloy formed part.

Example 4

(1) Adding raw material aluminum into a melting furnace, heating to 690 ℃, and stirring to melt the aluminum uniformly to a molten state;

(4) degassing and refining for 35min in a refining furnace by adding a refining agent into nitrogen at the refining temperature of 700 ℃, and standing for 32min after refining is finished;

(6) stretching, cooling and shaping to obtain the aluminum alloy formed part.

Example 5

(1) Adding raw material aluminum into a melting furnace, heating to 680 ℃, and stirring to melt the aluminum uniformly to a molten state;

(3) continuously stirring uniformly to an alloy system, and keeping the temperature for 60 min;

(4) degassing and refining for 20min in a refining furnace by adding a refining agent into nitrogen at the refining temperature of 700 ℃, and standing for 30min after refining is finished;

(6) stretching, cooling and shaping to obtain the aluminum alloy formed part.

TABLE 1

Table 1 is a composition table of the aluminum alloys prepared in the respective examples:

group of	Si	Fe	Cu	Mn	Mg	Cr	Zn	Ti	La	Sb	Impurity element	AI
													Example 1	0.45	0.55	0.18	0.2	0.16	0.16	0.11	0.11	0.13	0.15	≤0.1	Balance of
Example 2	0.55	0.57	0.15	0.5	0.22	0.19	0.15	0.15	0.16	0.17	≤0.1	Balance of
													Example 3	0.65	0.6	0.16	0.7	0.3	0.2	0.2	0.19	0.22	0.2	≤0.1	Balance of
Example 4	0.5	0.52	0.17	0.4	0.25	0.17	0.18	0.17	0.25	0.22	≤0.1	Balance of
													Example 5	0.4	0.5	0.15	0.6	0.18	0.18	0.17	0.16	0.2	0.25	≤0.1	Balance of

TABLE 2

Table 2 is a table of performance test data for the aluminum alloys prepared in the respective examples:

from the data, the tensile strength and the elongation at break of the aluminum alloy are gradually improved along with the increase of the addition of Sb, and the yield strength is also changed along with the addition of La, so that the performance of the aluminum alloy is integrally improved.

The above description is only for the preferred embodiment of the present invention and is not intended to limit the scope of the present invention, and all equivalent structural changes made by using the contents of the present specification or other related technical fields can be directly or indirectly applied thereto, and the same shall be included in the scope of the present invention.

Claims

1. The aluminum alloy material applied to the heat exchanger is characterized by comprising the following components in percentage by mass:

2. The aluminum alloy material for the heat exchanger as recited in claim 1, wherein the La is 0.15-0.25% by mass.

3. The aluminum alloy material for the heat exchanger as recited in claim 1, wherein the mass percentage of Sb is 0.12-0.25%.

4. A method for preparing the aluminum alloy material for heat exchangers according to any one of claims 1 to 3, wherein the method comprises the following steps:

(6) stretching, cooling and shaping to obtain the aluminum alloy formed part.

5. The method for preparing the aluminum alloy material according to claim 4, wherein the raw materials in the step (2) are as follows by mass percent: 0.4-0.65% of Si, 0.5-0.6% of Fe, 0.15-0.18% of Cu, 0.2-0.7% of Mn, 1-2.5% of Mg, 0.15-0.3% of Cr, 0.15-0.2% of Zn, 0.1-0.2% of Ti, 0.12-0.25% of La, 0.15-0.25% of Sb and less than 0.1% of impurity elements.

6. The method for preparing the aluminum alloy material according to claim 4, wherein the impurity elements include lead (Pb), tin (Sn) and bismuth (Bi) with the sum of mass percent being less than or equal to 0.1%.

7. The method for producing an aluminum alloy material according to claim 4, wherein the refining temperature in the refining furnace in step (4) is 700-.

8. The method for producing an aluminum alloy material according to claim 4, wherein the casting manner in the step (5) includes die casting, gravity casting, or squeeze casting.