A lightweight magnesium-copper alloy material with low thermal expansion and high thermal conductivity, its preparation method and application
By preparing a magnesium-copper alloy with a specific ratio to form the Mg2Cu phase, the problem of balancing thermal conductivity and thermal expansion in high-power electronic devices and precision structures is solved, achieving the effect of low expansion and high thermal conductivity, making it suitable for components with efficient heat dissipation and dimensional stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHONGQING UNIV
- Filing Date
- 2026-02-26
- Publication Date
- 2026-05-26
AI Technical Summary
Existing magnesium alloy materials cannot simultaneously meet the requirements of high thermal conductivity and low thermal expansion properties in high-power electronic devices and precision structures, leading to problems of thermal stress and dimensional instability.
By designing a specific ratio of magnesium-copper alloy, a large number of continuous or network-distributed Mg2Cu intermetallic compound phases are formed. Combined with melting, stirring and aging treatment under a protective atmosphere, a magnesium-copper alloy material with low thermal expansion and high thermal conductivity is prepared.
It achieves a coefficient of thermal expansion of less than 18×10-6/K and a thermal conductivity of more than 120 W/(m·K), while also being lightweight, making it suitable for components with efficient heat dissipation and dimensional stability.
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Figure CN122081735A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of alloy casting technology, and specifically to a lightweight, low-thermal-expansion, high-thermal-conductivity magnesium-copper alloy material, its preparation method, and its applications. Background Technology
[0002] Magnesium and its alloys are highly promising lightweight structural materials due to their low density and high specific strength. However, the thermal conductivity and thermal expansion properties of traditional commercial magnesium alloys (such as the AZ and AM series) are insufficient to meet the heat dissipation requirements of high-power electronic devices and the dimensional stability requirements of precision structures. For example, AZ91D typically has a thermal conductivity of only 50-70 W / (m·K) and an average coefficient of thermal expansion (25-200℃) as high as 26-28 × 10⁻⁶. -6 A high coefficient of thermal expansion ( / K) can easily induce thermal stress when the temperature changes, leading to component connection failure or functional malfunction.
[0003] Although pure magnesium has a high intrinsic thermal conductivity (approximately 156 W / (m·K)), its mechanical strength is insufficient, and its coefficient of thermal expansion is relatively high (approximately 25 × 10⁻⁶ W / (m·K)). -6 Alloying is a common method to improve strength, but it introduces solute atoms and a second phase, which enhances the scattering of phonons and electrons, resulting in a significant decrease in thermal conductivity. At the same time, the differences in thermal expansion behavior between different phases and the interface effect make the overall thermal expansion coefficient of the alloy complex. Copper, as an effective strengthening element, can improve strength by forming intermetallic compounds such as Mg2Cu, but traditional research believes that high alloy content will seriously impair thermal conductivity, forming an inherent contradiction between strength and thermal conductivity.
[0004] Therefore, there is an urgent need for a magnesium alloy material that can meet the requirements of high thermal conductivity and low thermal expansion. Summary of the Invention
[0005] One objective of this invention is to address the problem that it is difficult to simultaneously improve the strength, thermal conductivity, and dimensional stability of existing magnesium alloy materials, and to provide a magnesium-copper alloy material that combines high thermal conductivity, low coefficient of thermal expansion, and low density. The second objective of this invention is to provide a method for preparing a lightweight magnesium-copper alloy material with low thermal expansion and high thermal conductivity.
[0006] A third objective of this invention is to provide an application of a lightweight, low-thermal-expansion, high-thermal-conductivity magnesium-copper alloy material in components that require efficient heat dissipation, dimensional stability, and lightweight design.
[0007] To achieve the first objective of the invention, the present invention can be implemented through the following technical solution: a lightweight, low thermal expansion, and high thermal conductivity magnesium-copper alloy material, characterized in that, by weight percentage, it comprises the following components: Cu 25-30%, with the balance being Mg.
[0008] The beneficial effects of adopting the above technical solution are as follows: This invention uses magnesium and copper as the main components. By designing a magnesium and copper alloy with a specific content, a large number of continuous or network-distributed Mg2Cu intermetallic compound phases are formed in the microstructure after the alloy solidifies. This allows the resulting magnesium-copper alloy to maintain a density far lower than that of aluminum alloys while achieving a significantly lower coefficient of thermal expansion than conventional magnesium alloys (which can be reduced to 20 × 10⁻⁶). -6 The magnesium-copper binary alloy prepared by this invention exhibits a high thermal conductivity (below / K) and close to or better than that of some aluminum alloys (reaching over 120 W / (m·K)), successfully solving the technical challenge of simultaneously achieving thermal conductivity, dimensional stability, and high strength in lightweight materials. The alloy also possesses a low coefficient of thermal expansion: the average coefficient of linear expansion (CTE) within the temperature range of 25℃ to 300℃ is no higher than 18.0 × 10⁻⁶. -6 / K, preferably not higher than 16.5×10 -6 / K; High thermal conductivity: thermal conductivity not less than 130 W / (m·K) at 25℃ and not less than 120 W / (m·K) at 100℃; Low density: alloy density 2.3 g / cm³, achieving lightweight; the physical mechanism by which the alloy of the present invention achieves excellent comprehensive performance is as follows: low thermal expansion mechanism: the Mg2Cu phase itself has a thermal expansion coefficient much lower than that of the α-Mg matrix. When it is the main constituent phase and forms a continuous skeleton at the microscale, it can exert a strong mechanical constraint on the residual magnesium matrix with a high expansion rate, thereby significantly reducing the overall thermal expansion coefficient of the alloy; high thermal conductivity maintenance mechanism: although traditional theory believes that a large number of interfaces will hinder heat conduction, the Mg2Cu phase in this alloy and the α-Mg matrix can form a crystallographic coherent interface of Mg2Cu(044) / / α-Mg(0001). Such interfaces have a coherent atomic arrangement, low interface energy, and good bonding, which greatly reduces the scattering of phonons and electrons at the interface, resulting in a significant reduction in interface thermal resistance; therefore, heat flow can be efficiently transferred between the two phases, and the good thermal conductivity of the Mg2Cu phase itself can be fully utilized, thereby maintaining the excellent thermal conductivity of the alloy as a whole.
[0009] In one specific embodiment of the present invention, a lightweight, low thermal expansion, and high thermal conductivity magnesium-copper alloy material is provided, comprising the following components by weight percentage: Cu 30%, with the balance being Mg. To achieve the second objective of the invention, the present invention can be implemented through the following technical solution: providing a method for preparing a lightweight, low-thermal-expansion, high-thermal-conductivity magnesium-copper alloy material, comprising: Prepare raw materials according to the weight percentage of the magnesium-copper alloy material components, wherein Mg is added in the form of pure magnesium ingots and Cu is added in the form of pure copper blocks; Under a protective gas environment, pure magnesium ingots are heated to 710-730℃ until they are completely melted, then pure copper is added, and the temperature is raised to 740-760℃ and held for 15-30 minutes to obtain the melt. Stir the melt for 3-5 minutes, let it stand for 20-40 minutes, then pour it into a container and cool it with water to obtain an ingot. The ingot is subjected to aging treatment at 220-230℃ and held for 70-74 hours to obtain the product.
[0010] In one specific embodiment of the present invention, the protective gas is a mixture of SF6 and CO2 or high-purity argon; in the mixture of SF6 and CO2, the volume ratio of SF6 to CO2 is 1:199.
[0011] To achieve the third objective of the invention, the present invention provides an application of a lightweight, low-thermal-expansion, high-thermal-conductivity magnesium-copper alloy material in the preparation of component materials that require efficient heat dissipation, dimensional stability, and lightweight.
[0012] In one specific embodiment of the present invention, the components include high-power electronic devices and precision structures, LED lamp heat dissipation substrates, high-power integrated circuit packages and heat dissipation housings, and / or satellite optical instrument brackets.
[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention achieves low expansion (CTE as low as 16.4 × 10⁻⁶) in the magnesium alloy material by adding a high copper content and forming the Mg₂Cu phase. -6 With a unique combination of high thermal conductivity (TC up to 134 W / (m·K) at room temperature) and low density (1.937 g / cm³), its coefficient of thermal expansion is significantly lower than that of conventional magnesium and aluminum alloys. Its thermal conductivity is comparable to that of some cast aluminum alloys, but its density is about 30% lighter.
[0014] The invention has a simple composition and process: it is only a Mg-Cu binary system, the raw materials are readily available, the composition is simple to control, and it is easy to realize industrial production; it has broad application prospects: it is particularly suitable for occasions that require efficient heat dissipation, dimensional stability and lightweight, such as LED lamp heat dissipation substrates, high-power integrated circuit packaging and heat dissipation housings, satellite optical instrument brackets, aerospace precision structural components, etc. Attached Figure Description
[0015] Figure 1 The thermal expansion curves of the magnesium alloys prepared in Examples 1-2 and Comparative Examples 1-3 of this invention are shown. Figure 2 The graph shows the average coefficient of thermal expansion of the magnesium alloys prepared in Examples 1-2 and Comparative Examples 1-3 of this invention in the range of room temperature to 250°C. Figure 3The thermal conductivity of the cast magnesium alloys prepared in Examples 1-2 and Comparative Examples 1-3 of this invention; Figure 4 The XRD patterns of the cast magnesium alloys prepared in Example 2 and Comparative Examples 1 and 3 of this invention are shown below. Figure 5 The images show the SEM and energy dispersive spectroscopy (EDS) spectra of the cast magnesium alloys prepared in Example 2 and Comparative Example 1. Detailed Implementation
[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.
[0017] Example 1 A lightweight, low-thermal-expansion, high-thermal-conductivity magnesium-copper alloy material, comprising the following components by weight percentage: Cu 25% and Mg 75%.
[0018] The preparation method of the above-mentioned lightweight, low thermal expansion, and high thermal conductivity magnesium-copper alloy material includes the following steps: (1) Prepare raw materials according to the weight percentage of the magnesium-copper alloy material components, wherein Mg is added in the form of pure magnesium ingots (≥99.95%) and Cu is added in the form of pure copper blocks (≥99.9%). (2) Melting and alloying: In a resistance furnace or induction furnace with a protective atmosphere (a mixture of SF6 and CO2 with a volume fraction of 0.5-1.5% and a volume ratio of SF6 to CO2 of 1:199; or high-purity argon), pure magnesium ingots are heated to 710°C to completely melt them; then pure copper is added, and the temperature is raised to 760°C and held for 15 minutes to allow the copper to fully dissolve and alloy, thus obtaining a melt; (3) Melt treatment: The melt after heat preservation is thoroughly mechanically stirred for 5 minutes to ensure uniform composition; (4) Settling and casting: After stopping stirring, let the melt stand for 20 minutes to make the melt stable and allow any possible inclusions to float to the surface, and then water-cooled ingots are cast. (5) Aging treatment: The obtained ingot is aged at 220℃ for 70-74 hours to stabilize the alloy structure and properties.
[0019] Example 2 A lightweight, low-thermal-expansion, high-thermal-conductivity magnesium-copper alloy material, comprising the following components by weight percentage: Cu 30% and Mg 70%.
[0020] The preparation method of the above-mentioned lightweight, low thermal expansion, and high thermal conductivity magnesium-copper alloy material includes the following steps: (1) Prepare raw materials according to the weight percentage of the magnesium-copper alloy material components, wherein Mg is added in the form of pure magnesium ingots (≥99.95%) and Cu is added in the form of pure copper blocks (≥99.9%). (2) Melting and alloying: In a resistance furnace or induction furnace with a protective atmosphere (a mixture of SF6 and CO2 with a volume fraction of 0.5-1.5% and a volume ratio of SF6 to CO2 of 1:199; or high-purity argon), pure magnesium ingots are heated to 710-730℃ to completely melt them; then pure copper is added, and the temperature is raised to 740-760℃ and held for 15-30 minutes to allow the copper to fully dissolve and alloy, thus obtaining a melt; (3) Melt treatment: The melt after heat preservation is thoroughly mechanically stirred for 5 minutes to ensure uniform composition; (4) Settling and casting: After stopping stirring, let the melt stand for 20-40 minutes to make the melt stable and allow any possible inclusions to float to the surface, and then water-cooled ingots are cast. (5) Aging treatment: The obtained ingot is aged at 220-230℃ for 70-74 hours to stabilize the alloy structure and properties.
[0021] Example 3 A lightweight, low-thermal-expansion, high-thermal-conductivity magnesium-copper alloy material, comprising the following components by weight percentage: Cu 28% and Mg 72%.
[0022] The preparation method of the above-mentioned lightweight, low thermal expansion, and high thermal conductivity magnesium-copper alloy material includes the following steps: (1) Prepare raw materials according to the weight percentage of the magnesium-copper alloy material components, wherein Mg is added in the form of pure magnesium ingots (≥99.95%) and Cu is added in the form of pure copper blocks (≥99.9%). (2) Melting and alloying: In a resistance furnace or induction furnace with a protective atmosphere (a mixture of SF6 and CO2 with a volume fraction of 0.5-1.5% and a volume ratio of SF6 to CO2 of 1:199; or high-purity argon), pure magnesium ingots are heated to 730°C to completely melt them; then pure copper is added, and the temperature is raised to 740°C and held for 30 minutes to allow the copper to fully dissolve and alloy, thus obtaining a melt; (3) Melt treatment: The melt after heat preservation is thoroughly mechanically stirred for 5 minutes to ensure uniform composition; (4) Settling and casting: After stopping stirring, let the melt stand for 40 minutes to make the melt stable and allow any possible inclusions to float to the surface, and then water-cooled ingots are cast. (5) Aging treatment: The obtained ingot is aged at 230℃ for 70-74 hours to stabilize the alloy structure and properties.
[0023] Example 4 A lightweight, low-thermal-expansion, high-thermal-conductivity magnesium-copper alloy material, comprising the following components by weight percentage: Cu 26% and Mg 74%.
[0024] The preparation method of the above-mentioned lightweight, low thermal expansion, and high thermal conductivity magnesium-copper alloy material includes the following steps: (1) Prepare raw materials according to the weight percentage of the magnesium-copper alloy material components, wherein Mg is added in the form of pure magnesium ingots (≥99.95%) and Cu is added in the form of pure copper blocks (≥99.9%). (2) Melting and alloying: In a resistance furnace or induction furnace with a protective atmosphere (a mixture of SF6 and CO2 with a volume fraction of 0.5-1.5% and a volume ratio of SF6 to CO2 of 1:199; or high-purity argon), pure magnesium ingots are heated to 730°C to completely melt them; then pure copper is added, and the temperature is raised to 760°C and held for 15 minutes to allow the copper to fully dissolve and alloy, thus obtaining a melt; (3) Melt treatment: The melt after heat preservation is thoroughly mechanically stirred for 5 minutes to ensure uniform composition; (4) Settling and casting: After stopping stirring, let the melt stand for 20 minutes to make the melt stable and allow any possible inclusions to float to the surface, and then water-cooled ingots are cast. (5) Aging treatment: The obtained ingot is aged at 220℃ for 70-74 hours to stabilize the alloy structure and properties.
[0025] Example 5 A lightweight, low-thermal-expansion, high-thermal-conductivity magnesium-copper alloy material, comprising the following components by weight percentage: Cu 27% and Mg 73%.
[0026] The preparation method of the above-mentioned lightweight, low thermal expansion, and high thermal conductivity magnesium-copper alloy material includes the following steps: (1) Prepare raw materials according to the weight percentage of the magnesium-copper alloy material components, wherein Mg is added in the form of pure magnesium ingots (≥99.95%) and Cu is added in the form of pure copper blocks (≥99.9%). (2) Melting and alloying: In a resistance furnace or induction furnace with a protective atmosphere (a mixture of SF6 and CO2 with a volume fraction of 0.5-1.5% and a volume ratio of SF6 to CO2 of 1:199; or high-purity argon), pure magnesium ingots are heated to 710-730℃ to completely melt them; then pure copper is added, and the temperature is raised to 760℃ and held for 15 minutes to allow the copper to fully dissolve and alloy, thus obtaining a melt; (3) Melt treatment: The melt after heat preservation is thoroughly mechanically stirred for 5 minutes to ensure uniform composition; (4) Settling and casting: After stopping stirring, let the melt stand for 40 minutes to make the melt stable and allow any possible inclusions to float to the surface, and then water-cooled ingots are cast. (5) Aging treatment: The obtained ingot is aged at 230℃ for 70-74 hours to stabilize the alloy structure and properties.
[0027] Comparative Example 1 A lightweight, low-thermal-expansion, high-thermal-conductivity magnesium-copper alloy material, comprising the following components by weight percentage: Cu 5% and Mg 95%.
[0028] The preparation method of the above-mentioned lightweight, low thermal expansion, and high thermal conductivity magnesium-copper alloy material includes the following steps: (1) Prepare raw materials according to the weight percentage of the magnesium-copper alloy material components, wherein Mg is added in the form of pure magnesium ingots (≥99.95%) and Cu is added in the form of pure copper blocks (≥99.9%). (2) Melting and alloying: In a resistance furnace or induction furnace with a protective atmosphere (a mixture of SF6 and CO2 with a volume fraction of 0.5-1.5% and a volume ratio of SF6 to CO2 of 1:199; or high-purity argon), pure magnesium ingots are heated to 720°C to completely melt them; then pure copper is added, and the temperature is raised to 740°C and held for 15 minutes to allow the copper to fully dissolve and alloy, thus obtaining a melt; (3) Melt treatment: The melt after heat preservation is thoroughly mechanically stirred for 5 minutes to ensure uniform composition; (4) Settling and casting: After stopping stirring, let the melt stand for 20 minutes to make the melt stable and allow any possible inclusions to float to the surface, and then water-cooled ingots are cast. (5) Aging treatment: The obtained ingot is aged at 230℃ for 70-74 hours to stabilize the alloy structure and properties.
[0029] Comparative Example 2 A lightweight, low-thermal-expansion, high-thermal-conductivity magnesium-copper alloy material, comprising the following components by weight percentage: Cu 10% and Mg 90%.
[0030] The preparation method of the above-mentioned lightweight, low thermal expansion, and high thermal conductivity magnesium-copper alloy material includes the following steps: (1) Prepare raw materials according to the weight percentage of the magnesium-copper alloy material components, wherein Mg is added in the form of pure magnesium ingots (≥99.95%) and Cu is added in the form of pure copper blocks (≥99.9%). (2) Melting and alloying: In a resistance furnace or induction furnace with a protective atmosphere (a mixture of SF6 and CO2 with a volume fraction of 0.5-1.5% and a volume ratio of SF6 to CO2 of 1:199; or high-purity argon), pure magnesium ingots are heated to 710°C to completely melt them; then pure copper is added, and the temperature is raised to 740°C and held for 15 minutes to allow the copper to fully dissolve and alloy, thus obtaining a melt; (3) Melt treatment: The melt after heat preservation is thoroughly mechanically stirred for 5 minutes to ensure uniform composition; (4) Settling and casting: After stopping stirring, let the melt stand for 20 minutes to make the melt stable and allow any possible inclusions to float to the surface, and then water-cooled ingots are cast. (5) Aging treatment: The obtained ingot is aged at 220℃ for 70-74 hours to stabilize the alloy structure and properties.
[0031] Comparative Example 3 A lightweight, low-thermal-expansion, high-thermal-conductivity magnesium-copper alloy material, comprising the following components by weight percentage: Cu 15% and Mg 85%.
[0032] The preparation method of the above-mentioned lightweight, low thermal expansion, and high thermal conductivity magnesium-copper alloy material includes the following steps: (1) Prepare raw materials according to the weight percentage of the magnesium-copper alloy material components, wherein Mg is added in the form of pure magnesium ingots (≥99.95%) and Cu is added in the form of pure copper blocks (≥99.9%). (2) Melting and alloying: In a resistance furnace or induction furnace with a protective atmosphere (a mixture of SF6 and CO2 with a volume fraction of 0.5-1.5% and a volume ratio of SF6 to CO2 of 1:199; or high-purity argon), pure magnesium ingots are heated to 710°C to completely melt them; then pure copper is added, and the temperature is raised to 760°C and held for 20 minutes to allow the copper to fully dissolve and alloy, thus obtaining a melt; (3) Melt treatment: The melt after heat preservation is thoroughly mechanically stirred for 5 minutes to ensure uniform composition; (4) Settling and casting: After stopping stirring, let the melt stand for 30 minutes to make the melt stable and allow any possible inclusions to float to the surface, and then water-cooled ingots are cast. (5) Aging treatment: The obtained ingot is aged at 220℃ for 70-74 hours to stabilize the alloy structure and properties.
[0033] The magnesium alloy composition tables of Examples 1-5 and Comparative Examples 1-3 are shown in the table below.
[0034] Table 1. Alloy composition of Examples 1-5 and Comparative Examples 1-3 (wt. % represents mass fraction)
[0035] Experimental Example 1) Sample preparation Pure magnesium and pure Cu were weighed according to the mass fraction of the magnesium-copper alloy formula components. For both the comparative and example samples, 500 grams of raw materials were prepared per sample. After weighing, the surface of the raw materials was polished to remove surface impurities and oxides. Then, the pure magnesium ingot was placed in a stainless steel crucible, which was then placed in a resistance furnace at 720°C. SF6 and CO2 protective gases (SF6 to CO2 volume ratio 1:199) were introduced into the furnace. After the pure magnesium ingot melted, pure Cu was added, and the furnace temperature was raised to 760°C. The high temperature helped the impurities in the melt settle. After holding at 760°C for 30 minutes, the slag on the surface of the melt was removed. The melt was then stirred for 5 minutes using a stirrer to ensure uniform element distribution. The melt was held at this temperature for another 30 minutes, and then the crucible was removed and water-cooled to obtain the ingot. The ingot is then aged at 225 ℃ for 72 hours, with a holding time of 70-74 hours, to stabilize the alloy structure and properties.
[0036] (2) Performance testing and morphological characterization The thermal expansion test samples were machined into cylinders with a diameter of φ5 mm × 25 mm. The tensile test samples were machined into round bar specimens with a gauge length of 25 mm and a diameter of 5 mm according to GB / T 228.1-2021 standard. The thermal expansion behavior was tested using a Netzsch DIL 502 Expedis Classic thermal dilatometer at a heating rate of 5 K / min in the temperature range of 25℃ to 300℃. The room temperature tensile test was conducted using a universal testing machine with a beam displacement speed of 1.5 mm / s. The alloy density was determined by the water displacement method, and the thermal conductivity was calculated by combining the thermal diffusivity and specific heat capacity data.
[0037] See Figure 1 and Figure 2 ,from Figure 1 and Figure 2 The thermal expansion test results show that as the Cu content increases, the average thermal expansion coefficient of the alloy in the range of 25-300℃ shows a systematic decrease, especially after the Cu content exceeds 25 wt.%, the decrease is significantly greater. Figure 4X-ray diffraction analysis confirmed the presence of an α-Mg matrix and Mg₂Cu precipitates in the alloy. The decrease in the coefficient of thermal expansion is mainly attributed to the formation and microstructure evolution of the Mg₂Cu phase. The Mg₂Cu phase has a lower intrinsic coefficient of thermal expansion than α-Mg. When it is dispersed as a second phase in the α-Mg matrix, it not only directly contributes to the lower thermal expansion but also constrains the thermal expansion of the matrix through the bonding at the interface between the two phases, thereby macroscopically reducing the overall expansion rate. Furthermore, from... Figure 5 It can be seen that when the Cu content reaches 30 wt.%, scanning electron microscopy shows that the microstructure of the alloy undergoes a fundamental change, from α-Mg as the matrix to Mg2Cu phase as the continuous matrix phase. This reversal of the microstructure makes the low-expansion Mg2Cu phase the dominant phase, resulting in a significant decrease in the thermal expansion coefficient of the alloy.
[0038] Regarding thermal conductivity, although the introduction of a large amount of second phase into the alloy usually leads to a decrease in thermal conductivity due to increased interfacial scattering, the alloy in this system still maintains a high thermal conductivity, such as... Figure 3 As shown, when the Cu content is 30 wt.%, the room temperature thermal conductivity is still higher than 130 W / (m·K). This is mainly due to the high intrinsic thermal conductivity of the Mg2Cu phase itself, and the continuous network structure formed in the microstructure provides an efficient pathway for phonon transport. Therefore, while obtaining low thermal expansion characteristics, the alloy effectively maintains good heat transport capacity by relying on the high thermal conductivity of the Mg2Cu phase itself and the continuous thermally conductive network formed.
[0039] In summary, this invention regulates the phase composition and microstructure of Mg-Cu alloys through compositional design, promoting a structural transformation from α-Mg as the matrix to Mg2Cu as the matrix. This transformation not only effectively reduces the coefficient of thermal expansion by significantly increasing the proportion of low-expansion phases and their constraint effect on the matrix, but also ensures the high thermal conductivity of the alloy by utilizing the high intrinsic thermal conductivity of the Mg2Cu phase and its continuous thermally conductive framework.
Claims
1. A lightweight, low-thermal-expansion, high-thermal-conductivity magnesium-copper alloy material, characterized in that, The components include the following content by weight percentage: Cu 25-30%, with the balance being Mg.
2. The lightweight, low-thermal-expansion, high-thermal-conductivity magnesium-copper alloy material according to claim 1, characterized in that, The component, by weight percentage, includes the following: Cu 30%, with the balance being Mg.
3. The method for preparing the lightweight, low-thermal-expansion, high-thermal-conductivity magnesium-copper alloy material according to any one of claims 1-2, characterized in that, include: Prepare raw materials according to the weight percentage of the magnesium-copper alloy material components, wherein Mg is added in the form of pure magnesium ingots and Cu is added in the form of pure copper blocks; Under a protective gas environment, pure magnesium ingots are heated to 710-730℃ until they are completely melted, then pure copper is added, and the temperature is raised to 740-760℃ and held for 15-30 minutes to obtain the melt. Stir the melt for 3-5 minutes, let it stand for 20-40 minutes, and then water-cool it into an ingot. The ingot is subjected to aging treatment at 220-230℃ and held for 70-74 hours to obtain the product.
4. The method for preparing the lightweight, low-thermal-expansion, high-thermal-conductivity magnesium-copper alloy material according to claim 3, characterized in that, The protective gas is a mixture of SF6 and CO2 or high-purity argon; in the mixture of SF6 and CO2, the volume ratio of SF6 to CO2 is 1:
199.
5. The application of the lightweight, low thermal expansion, and high thermal conductivity magnesium-copper alloy material according to any one of claims 1-2 in the preparation of component materials that require efficient heat dissipation, dimensional stability, and lightweight.
6. The application according to claim 5, characterized in that, The components include high-power electronic devices and precision structures, LED lighting heat dissipation substrates, high-power integrated circuit packages and heat dissipation housings, and / or satellite optical instrument brackets.