A method of controlling magnesium alloy basal plane precipitates

Abstract

The application discloses a method for regulating magnesium alloy basal precipitates, and belongs to the technical field of magnesium alloys. The method comprises the following steps: melting and casting raw materials according to a preset Mg-Gd-Y-Zn-Mn alloy composition and content, and then performing rapid solidification and artificial aging treatment; the Mg-Gd-Y-Zn-Mn alloy comprises 8.67%-8.89% of Gd, 3.85%-3.95% of Y, 3.28%-6.47% of Zn and 0.96%-1.96% of Mn in terms of mass percentage, and the balance is magnesium and inevitable impurities; and (Gd+Y):Zn=1:1 or 2:1 in terms of atomic percentage. According to the above method, high-density gamma'' basal precipitates are maintained during peak aging and overaging, and the process window for forming high-density distributed gamma'' basal precipitates in the Mg-Gd-Y-Zn-Mn alloy is effectively increased.

Description

Technical Field

[0001] This invention relates to the field of magnesium alloy technology, and more specifically, to a method for controlling the precipitated phases on the basal surface of magnesium alloys. Background Technology

[0002] γ'' basal plane precipitates are important strengthening phases in magnesium alloys, with their core function being to significantly improve the alloy's strength. High-density γ'' basal plane precipitate stacking can occur in Mg-Gd(-Y)-Ag alloys because Ag elements in the alloy promote the formation of high-density γ'' basal plane precipitates, but this method is costly. Furthermore, high-density γ'' basal plane precipitate stacking may also occur in Mg-Gd-Y-Zn-Mn alloys, but a large number of high-density γ'' basal plane precipitates only appear during peak aging in the preparation process. The density of γ'' basal plane precipitates in the over-aging stage, far from the peak aging time, is significantly lower than that formed during peak aging, resulting in a sparser distribution of γ'' basal plane precipitates.

[0003] Currently, there is no effective method to extend the process window for the formation of high-density γ'' basal plane precipitates in Mg-Gd-Y-Zn-Mn alloys.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a method for controlling the precipitated phases on the basal surface of magnesium alloys, so as to solve or improve the above-mentioned technical problems.

[0006] This invention can be implemented as follows:

[0007] This invention provides a method for controlling the precipitation phases on the basal surface of magnesium alloys, comprising the following steps: melting and casting raw materials according to a preset Mg-Gd-Y-Zn-Mn alloy composition and content to obtain an alloy ingot; rapidly solidifying the alloy ingot to obtain an alloy strip; and artificially aging the alloy strip.

[0008] By mass percentage, the Mg-Gd-Y-Zn-Mn alloy comprises 8.67%~8.89% Gd, 3.85%~3.95% Y, 3.28%~6.47% Zn, and 0.96%~1.96% Mn, with the balance being magnesium and unavoidable impurities; and by atomic percentage, (Gd+Y):Zn = 1:1 or 2:1.

[0009] In an optional embodiment, the Mg-Gd-Y-Zn-Mn alloy comprises, by mass percentage, 8.71% Gd, 3.87% Y, 6.47% Zn and 0.96% Mn, with the balance being magnesium and unavoidable impurities.

[0010] Alternatively, in atomic percentage, the Mg-Gd-Y-Zn-Mn alloy comprises 1.58% Gd, 1.24% Y, 2.82% Zn and 0.50% Mn, with the balance being magnesium and unavoidable impurities.

[0011] In an optional embodiment, the Mg-Gd-Y-Zn-Mn alloy comprises, by mass percentage, 8.89% Gd, 3.95% Y, 3.30% Zn and 0.98% Mn, with the balance being magnesium and unavoidable impurities.

[0012] Alternatively, in atomic percentage, the Mg-Gd-Y-Zn-Mn alloy comprises 1.58% Gd, 1.24% Y, 1.41% Zn and 0.50% Mn, with the balance being magnesium and unavoidable impurities.

[0013] In an optional embodiment, the Mg-Gd-Y-Zn-Mn alloy comprises, by mass percentage, 8.67% Gd, 3.85% Y, 6.43% Zn and 1.92% Mn, with the balance being magnesium and unavoidable impurities.

[0014] Alternatively, in atomic percentage, the Mg-Gd-Y-Zn-Mn alloy comprises 1.58% Gd, 1.24% Y, 2.82% Zn and 1.0% Mn, with the balance being magnesium and unavoidable impurities.

[0015] In an optional embodiment, the Mg-Gd-Y-Zn-Mn alloy comprises, by mass percentage, 8.84% Gd, 3.92% Y, 3.28% Zn and 1.96% Mn, with the balance being magnesium and unavoidable impurities.

[0016] Alternatively, in atomic percentage, the Mg-Gd-Y-Zn-Mn alloy comprises 1.58% Gd, 1.24% Y, 1.41% Zn and 1.0% Mn, with the balance being magnesium and unavoidable impurities.

[0017] In optional embodiments, the raw materials include pure Mg, pure Zn, Mg-Gd master alloy containing 25wt%~30wt% Gd, Mg-Y master alloy containing 25wt%~30wt% Y, and Mg-Mn master alloy containing 5wt%~10wt% Mn.

[0018] In an optional embodiment, rapid solidification is carried out in a vacuum spinning machine, during which the circumferential speed of the copper roller is not less than 5 m / s; preferably 5 m / s to 15 m / s.

[0019] In an optional implementation, the temperature for artificial aging treatment is 150°C to 250°C.

[0020] In an optional implementation, the density of the γ'' basal precipitate at the peak aging is ρ1, and the density of the γ'' basal precipitate after the peak aging and artificial aging treatment for 200 hours is ρ2, where ρ2 ≥ 95% ρ1.

[0021] In an optional implementation, ρ2 ≥ 98% ρ1.

[0022] The beneficial effects of this invention include:

[0023] This invention creatively limits the atomic ratio of Gd, Y, and Zn in magnesium alloys, and performs melting, casting, rapid solidification, and artificial aging treatment on Mg-Gd-Y-Zn-Mn alloys that meet specific elemental compositions. This results in a high-density distribution of γ'' basal plane precipitates during both peak aging and over-aging processes, effectively increasing the process window for the formation of high-density γ'' basal plane precipitates in Mg-Gd-Y-Zn-Mn alloys. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 Transmission electron microscope (TEM) images of magnesium alloy sample 1 and magnesium alloy sample 2;

[0026] Figure 2 Transmission electron microscopy images of magnesium alloy sample 3 and magnesium alloy sample 4;

[0027] Figure 3 Transmission electron microscopy (TEM) images of magnesium alloy samples 5 and 6. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0029] The method for regulating the precipitated phases on the basal surface of magnesium alloys provided by the present invention will be described in detail below.

[0030] This invention provides a method for controlling the precipitation phases on the basal surface of magnesium alloys, comprising the following steps: melting and casting the raw materials according to the preset Mg-Gd-Y-Zn-Mn alloy composition and content to obtain an alloy ingot; rapidly solidifying the alloy ingot to obtain an alloy strip; and artificially aging the alloy strip.

[0031] By mass percentage, the Mg-Gd-Y-Zn-Mn alloy comprises 8.67%~8.89% Gd, 3.85%~3.95% Y, 3.28%~6.47% Zn, and 0.96%~1.96% Mn, with the balance being magnesium and unavoidable impurities; and by atomic percentage, (Gd+Y):Zn = 1:1 or 2:1.

[0032] It should be noted that, through research, the inventors creatively proposed that, while satisfying the above-mentioned mass percentage range, Gd, Y, Zn, and Mn can further control the atomic percentage of (Gd+Y):Zn to be 1:1 or 2:1. This allows for the maintenance of a high-density γ'' basal plane precipitate distribution during artificial aging treatment, both during peak aging and over-aging, after melting, casting, and rapid solidification. This effectively increases the process window for the formation of a high-density γ'' basal plane precipitate in the Mg-Gd-Y-Zn-Mn alloy.

[0033] Specifically, the basal precipitates of the Mg-Gd-Y-Zn-Mn alloy include γ' and γ'' basal precipitates. This invention increases the Zn content and sets the (Gd+Y) / Zn atomic ratio to 1:1 or 2:1. When the (Gd+Y) / Zn atomic ratio is 1:1, it can increase the content of γ' phase cells. During aging, some γ' phase will transform into γ'' phase, thereby extending the process window for γ'' basal precipitates. When the (Gd+Y) / Zn atomic ratio is 2:1, it can increase the content of γ'' phase cells, promote the formation of γ'' basal precipitates, and form more γ'' basal precipitates after over-aging treatment, thus maintaining a high density of γ'' basal precipitate distribution during over-aging.

[0034] In some alternative embodiments, the Mg-Gd-Y-Zn-Mn alloy comprises, by mass percentage, 8.71% Gd, 3.87% Y, 6.47% Zn, and 0.96% Mn, with the balance being magnesium and unavoidable impurities. That is, by atomic percentage, the Mg-Gd-Y-Zn-Mn alloy comprises 1.58% Gd, 1.24% Y, 2.82% Zn, and 0.50% Mn, with the balance being magnesium and unavoidable impurities.

[0035] In some alternative embodiments, the Mg-Gd-Y-Zn-Mn alloy comprises, by mass percentage, 8.89% Gd, 3.95% Y, 3.30% Zn, and 0.98% Mn, with the balance being magnesium and unavoidable impurities. That is, by atomic percentage, the Mg-Gd-Y-Zn-Mn alloy comprises 1.58% Gd, 1.24% Y, 1.41% Zn, and 0.50% Mn, with the balance being magnesium and unavoidable impurities.

[0036] In some alternative embodiments, the Mg-Gd-Y-Zn-Mn alloy comprises 8.67% Gd, 3.85% Y, 6.43% Zn, and 1.92% Mn, with the balance being magnesium and unavoidable impurities. That is, on an atomic percentage basis, the Mg-Gd-Y-Zn-Mn alloy comprises 1.58% Gd, 1.24% Y, 2.82% Zn, and 1.0% Mn, with the balance being magnesium and unavoidable impurities.

[0037] In some alternative embodiments, the Mg-Gd-Y-Zn-Mn alloy comprises 8.84% Gd, 3.92% Y, 3.28% Zn, and 1.96% Mn, with the balance being magnesium and unavoidable impurities. That is, on an atomic percentage basis, the Mg-Gd-Y-Zn-Mn alloy comprises 1.58% Gd, 1.24% Y, 1.41% Zn, and 1.0% Mn, with the balance being magnesium and unavoidable impurities.

[0038] In some alternative embodiments, the raw materials may include pure Mg, pure Zn, Mg-Gd master alloy containing 25wt%~30wt% Gd, Mg-Y master alloy containing 25wt%~30wt% Y, and Mg-Mn master alloy containing 5wt%~10wt% Mn.

[0039] In some alternative implementations, rapid solidification is carried out in a vacuum spinning machine, during which the circumferential speed of the copper roller is not less than 5 m / s, for example, it can be 5 m / s to 15 m / s, such as 5 m / s, 10 m / s or 15 m / s.

[0040] In some alternative implementations, the temperature for artificial aging treatment can be 150℃~250℃, such as 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, 210℃, 220℃, 230℃, 240℃ or 250℃, or other values ​​within the range of 150℃~250℃.

[0041] In some more specific embodiments, magnesium alloys with high-density γ'' basal plane precipitates can be prepared in the following manner:

[0042] (1) Calculate the required raw material weight according to the preset Mg-Gd-Y-Zn-Mn alloy composition and content. The raw materials are pure Mg (purity of 99.9wt%), pure Zn (purity of 99.9wt%), Mg-Gd master alloy containing 25wt%~30wt%Gd, Mg-Y master alloy containing 25wt%~30wt%Y and Mg-Mn master alloy containing 5wt%~10wt%Mn. Under argon protection, the alloy ingots are melted and cast in an electromagnetic induction furnace.

[0043] (2) After crushing the above alloy ingot, place it into a quartz tube, put the quartz tube into the induction coil of the single-roller vacuum belt spinning machine, and use argon gas to purge the sealed cavity of the vacuum belt spinning machine to a high vacuum of 5×10. -3 Below Pa, high-purity argon is then introduced as a protective gas. The alloy is remelted by induction heating. After the alloy is melted evenly, spray casting begins. High-pressure argon gas is used to continuously spray the liquid alloy onto the surface of a high-speed rotating copper rod. Under the condition that the circumferential speed of the copper rod is 5 m / s or 10 m / s, alloy strips are obtained.

[0044] (3) The above alloy strips are subjected to artificial aging treatment. The artificial aging temperature is 200℃, and the holding time is determined according to the aging hardness curve. The strips are taken out and water-cooled at any time window between the peak aging time and 200h (inclusive). Magnesium alloys containing high-density γ'' basal plane precipitates can be obtained.

[0045] In some optional implementations, the density of the γ'' basal precipitate corresponding to the peak aging is ρ1, and the density of the γ'' basal precipitate corresponding to the artificial aging treatment for 200 h after the peak aging is ρ2, where ρ2 ≥ 95% ρ1, further, ρ2 ≥ 98% ρ1, and even further, ρ2 ≥ 99% ρ1, for example, it can be 99% ρ1 to 100% ρ1.

[0046] That is, compared with the density of the γ'' basal precipitate at the peak aging, the density of the γ'' basal precipitate after 200h of artificial aging treatment remains basically unchanged.

[0047] Continuing from the above, the above method effectively increases the process window for forming a high-density distribution of γ'' basal plane precipitates in Mg-Gd-Y-Zn-Mn alloys. That is, in the prior art, magnesium alloys with a high-density distribution of γ'' basal plane precipitates can only be obtained during peak aging (after peak aging, the density of the γ'' basal plane precipitates decreases significantly, leading to a decrease in the hardness of the magnesium alloy). However, the method provided in this application can effectively maintain the amount of γ'' basal plane precipitates for a long time after peak aging and over-aging, thereby obtaining magnesium alloys with high hardness within the above time period, which has high application and promotion value.

[0048] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0049] All raw materials and equipment used in the following preparation process were purchased commercially.

[0050] Example 1

[0051] This embodiment provides a method for controlling the precipitated phases on the basal surface of magnesium alloys, including the following steps:

[0052] (1) The required raw material weight was calculated according to the principle that "the Mg-Gd-Y-Zn-Mn alloy, by atomic percentage, comprises 1.58% Gd, 1.24% Y, 2.82% Zn, and 0.50% Mn, with the balance being magnesium and unavoidable impurities." The raw materials used were pure Mg (99.9 wt%), pure Zn (99.9 wt%), a Mg-Gd master alloy containing 30 wt% Gd, a Mg-Y master alloy containing 25 wt% Y, and a Mg-Mn master alloy containing 10 wt% Mn. Under argon protection, the required raw materials were melted together in an electromagnetic induction furnace (740 °C) and cast to obtain an alloy ingot.

[0053] That is, by mass percentage, the above Mg-Gd-Y-Zn-Mn alloy comprises 8.71% Gd, 3.87% Y, 6.47% Zn and 0.96% Mn, with the balance being magnesium and unavoidable impurities.

[0054] (2) After crushing the above alloy ingot, place it into a quartz tube, put the quartz tube into the induction coil of the single-roller vacuum belt spinning machine, and use argon gas to purge the sealed cavity of the vacuum belt spinning machine to a high vacuum of 5×10. -3 Below Pa, high-purity argon is then introduced as a protective gas, and the alloy is remelted by induction heating (740℃). After the alloy is melted uniformly, spray casting begins. High-pressure argon gas is used to continuously spray the liquid alloy onto the surface of a high-speed rotating copper rod, and alloy strips are obtained under the condition that the circumferential speed of the copper rod is 10m / s.

[0055] (3) The above alloy strips were subjected to artificial aging treatment at a temperature of 200°C. The materials were taken out and water-cooled at the peak aging (140h) and at 200h of artificial aging treatment, respectively, to obtain magnesium alloy sample 1 and magnesium alloy sample 2.

[0056] Example 2

[0057] This embodiment provides a method for controlling the precipitated phases on the basal surface of magnesium alloys, including the following steps:

[0058] (1) The required raw material weight was calculated according to the principle that "the Mg-Gd-Y-Zn-Mn alloy, by atomic percentage, comprises 1.58% Gd, 1.24% Y, 1.41% Zn, and 0.50% Mn, with the balance being magnesium and unavoidable impurities." The raw materials used were pure Mg (99.9 wt%), pure Zn (99.9 wt%), a Mg-Gd master alloy containing 30 wt% Gd, a Mg-Y master alloy containing 25 wt% Y, and a Mg-Mn master alloy containing 10 wt% Mn. Under argon protection, the required raw materials were melted together in an electromagnetic induction furnace (740 °C) and cast to obtain an alloy ingot.

[0059] That is, by mass percentage, the above Mg-Gd-Y-Zn-Mn alloy comprises 8.89% Gd, 3.95% Y, 3.30% Zn and 0.98% Mn, with the balance being magnesium and unavoidable impurities.

[0060] (2) After crushing the above alloy ingot, place it into a quartz tube, put the quartz tube into the induction coil of the single-roller vacuum belt spinning machine, and use argon gas to purge the sealed cavity of the vacuum belt spinning machine to a high vacuum of 5×10. -3 Below Pa, high-purity argon is then introduced as a protective gas, and the alloy is remelted by induction heating (740℃). After the alloy is melted uniformly, spray casting begins. High-pressure argon gas is used to continuously spray the liquid alloy onto the surface of a high-speed rotating copper rod, and alloy strips are obtained under the condition that the circumferential speed of the copper rod is 10m / s.

[0061] (3) The above alloy strips are subjected to artificial aging treatment at a temperature of 200°C. The material is taken out and water-cooled during the peak aging and the 200h artificial aging treatment to obtain a magnesium alloy containing high-density γ'' basal plane precipitates.

[0062] Example 3

[0063] This embodiment provides a method for controlling the precipitated phases on the basal surface of magnesium alloys, including the following steps:

[0064] (1) The required raw material weight was calculated according to the principle that "the Mg-Gd-Y-Zn-Mn alloy, by atomic percentage, comprises 1.58% Gd, 1.24% Y, 2.82% Zn, and 1.0% Mn, with the balance being magnesium and unavoidable impurities." The raw materials used were pure Mg (99.9 wt%), pure Zn (99.9 wt%), a Mg-Gd master alloy containing 30 wt% Gd, a Mg-Y master alloy containing 25 wt% Y, and a Mg-Mn master alloy containing 10 wt% Mn. Under argon protection, the required raw materials were melted together in an electromagnetic induction furnace (740 °C) and cast to obtain an alloy ingot.

[0065] That is, the above-mentioned Mg-Gd-Y-Zn-Mn alloy includes 8.67% Gd, 3.85% Y, 6.43% Zn and 1.92% Mn, with the balance being magnesium and unavoidable impurities.

[0066] (2) After crushing the above alloy ingot, place it into a quartz tube, put the quartz tube into the induction coil of the single-roller vacuum belt spinning machine, and use argon gas to purge the sealed cavity of the vacuum belt spinning machine to a high vacuum of 5×10. -3 Below Pa, high-purity argon is then introduced as a protective gas, and the alloy is remelted by induction heating (740℃). After the alloy is melted uniformly, spray casting begins. High-pressure argon gas is used to continuously spray the liquid alloy onto the surface of a high-speed rotating copper rod, and alloy strips are obtained under the condition that the circumferential speed of the copper rod is 10m / s.

[0067] (3) The above alloy strips are subjected to artificial aging treatment at a temperature of 200°C. The material is taken out and water-cooled during the peak aging and the 200h artificial aging treatment to obtain a magnesium alloy containing high-density γ'' basal plane precipitates.

[0068] Example 4

[0069] This embodiment provides a method for controlling the precipitated phases on the basal surface of magnesium alloys, including the following steps:

[0070] (1) The required raw material weight was calculated according to the principle that "the Mg-Gd-Y-Zn-Mn alloy, by atomic percentage, comprises 1.58% Gd, 1.24% Y, 1.41% Zn, and 1.0% Mn, with the balance being magnesium and unavoidable impurities." The raw materials used were pure Mg (99.9 wt%), pure Zn (99.9 wt%), a Mg-Gd master alloy containing 30 wt% Gd, a Mg-Y master alloy containing 25 wt% Y, and a Mg-Mn master alloy containing 10 wt% Mn. Under argon protection, the required raw materials were melted together in an electromagnetic induction furnace (740 °C) and cast to obtain an alloy ingot.

[0071] That is, the above-mentioned Mg-Gd-Y-Zn-Mn alloy includes 8.84% Gd, 3.92% Y, 3.28% Zn and 1.96% Mn, with the balance being magnesium and unavoidable impurities.

[0072] (2) After crushing the above alloy ingot, place it into a quartz tube, put the quartz tube into the induction coil of the single-roller vacuum belt spinning machine, and use argon gas to purge the sealed cavity of the vacuum belt spinning machine to a high vacuum of 5×10. -3Below Pa, high-purity argon is then introduced as a protective gas, and the alloy is remelted by induction heating (740℃). After the alloy is melted uniformly, spray casting begins. High-pressure argon gas is used to continuously spray the liquid alloy onto the surface of a high-speed rotating copper rod, and alloy strips are obtained under the condition that the circumferential speed of the copper rod is 10m / s.

[0073] (3) The above alloy strips were subjected to artificial aging treatment at a temperature of 200°C. The materials were taken out and water-cooled at the peak aging (90h) and at the artificial aging treatment (200h) to obtain magnesium alloy sample 3 and magnesium alloy sample 4, respectively.

[0074] Comparative Example 1

[0075] The difference between this comparative example and Example 1 is that the alloy composition is designed as follows: by mass percentage, the Mg-Gd-Y-Zn-Mn alloy comprises 8.75% Gd, 4.25% Y, 1.2% Zn, and 1.5% Mn, with the balance being magnesium and unavoidable impurities. That is, by atomic percentage, the Mg-Gd-Y-Zn-Mn alloy comprises 1.54% Gd, 1.32% Y, 0.51% Zn, and 0.75% Mn, with the balance being magnesium and unavoidable impurities.

[0076] The comparative samples were obtained by taking out and water cooling after peak aging (50h) and artificial aging treatment (200h), respectively, and are magnesium alloy sample 5 and magnesium alloy sample 6.

[0077] Comparative Example 2

[0078] The difference between this comparative example and Example 1 is that the alloy composition is designed as follows: by mass percentage, the Mg-Gd-Y-Zn-Mn alloy comprises 8.89% Gd, 3.95% Y, 1% Zn, and 1% Mn, with the balance being magnesium and unavoidable impurities. That is, by atomic percentage, the Mg-Gd-Y-Zn-Mn alloy comprises 1.55% Gd, 1.22% Y, 0.42% Zn, and 0.5% Mn, with the balance being magnesium and unavoidable impurities.

[0079] Comparative Example 3

[0080] The difference between this comparative example and Example 1 is that the alloy composition is designed as follows: by mass percentage, the Mg-Gd-Y-Zn-Mn alloy comprises 9% Gd, 4% Y, 1% Zn, and 2% Mn, with the balance being magnesium and unavoidable impurities. That is, by atomic percentage, the Mg-Gd-Y-Zn-Mn alloy comprises 1.59% Gd, 1.25% Y, 0.42% Zn, and 1.01% Mn, with the balance being magnesium and unavoidable impurities.

[0081] Test case

[0082] (1) Taking Example 1 as an example, the obtained magnesium alloy sample 1 and magnesium alloy sample 2 were observed by transmission electron microscopy, and the results are as follows: Figure 1 As shown in (a) and (b).

[0083] Depend on Figure 1 It can be seen that the γ'' basal plane precipitates in both magnesium alloy sample 1 and magnesium alloy sample 2 exhibit a high density distribution. Furthermore, the density of the γ'' basal plane precipitates in magnesium alloy sample 2 obtained after peak aging is not significantly less than that in magnesium alloy sample 1 obtained after peak aging.

[0084] (2) Taking Example 4 as an example, the obtained magnesium alloy sample 3 and magnesium alloy sample 4 were observed by transmission electron microscopy, and the results are as follows: Figure 2 As shown in (a) and (b).

[0085] Depend on Figure 2 It can be seen that the γ'' basal plane precipitates in magnesium alloy samples 3 and 4 both exhibit a high density distribution. Furthermore, the density of the γ'' basal plane precipitates in magnesium alloy sample 4 after peak aging is not significantly less than that in magnesium alloy sample 3 after peak aging.

[0086] (3) Taking Comparative Example 1 as an example, the obtained magnesium alloy sample 5 and magnesium alloy sample 6 were observed by transmission electron microscopy, and the results are as follows: Figure 3 As shown in (a) and (b).

[0087] Depend on Figure 3 It can be seen that the γ'' basal plane precipitates in magnesium alloy sample 5 exhibit a high density distribution, but the density of the γ'' basal plane precipitates in magnesium alloy sample 6 obtained after peak aging is significantly less than that in magnesium alloy sample 5 obtained during peak aging, with only a few γ'' basal plane precipitates present.

[0088] (4) Taking Comparative Examples 2 and 3 as examples, the density (ρ1) of the γ'' basal precipitate corresponding to the peak aging and the density (ρ2) of the γ'' basal precipitate corresponding to the artificial aging treatment after the peak aging are compared. The results show that the density of the γ'' basal precipitate corresponding to the artificial aging treatment after the peak aging of the two comparative examples is significantly lower than the density of the γ'' basal precipitate at the peak aging, ρ2 < 95% ρ1.

[0089] In summary, by increasing the Zn content and setting the (Gd+Y) / Zn atomic ratio to 1:1 or 2:1, this invention can maintain a large number of γ'' basal plane precipitates even after peak aging. That is, it maintains a high density of γ'' basal plane precipitates during both peak aging and over-aging processes, effectively increasing the process window for forming a high density of γ'' basal plane precipitates in Mg-Gd-Y-Zn-Mn alloys.

[0090] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of regulating a magnesium alloy based surface precipitate phase, characterized by, The method comprises the following steps: melting and casting raw materials according to a preset Mg-Gd-Y-Zn-Mn alloy composition and content to obtain an alloy ingot; rapidly solidifying the alloy ingot to obtain an alloy strip; and performing artificial aging treatment on the alloy strip. The Mg-Gd-Y-Zn-Mn alloy comprises 8.67% to 8.89% of Gd, 3.85% to 3.95% of Y, 3.28% to 6.47% of Zn and 0.96% to 1.96% of Mn in terms of mass percentage, and the balance is magnesium and inevitable impurities; and (Gd+Y):Zn = 1:1 or 2:1 in terms of atomic percentage. The density of the γ'' basal plane precipitated phase corresponding to the peak aging is ρ1, and the density of the γ'' basal plane precipitated phase corresponding to the artificial aging treatment for 200 hours after the peak aging is ρ2, and ρ2 ≥ 95%ρ1.

2. The method of claim 1, wherein, The Mg-Gd-Y-Zn-Mn alloy comprises 8.71% of Gd, 3.87% of Y, 6.47% of Zn and 0.96% of Mn in terms of mass percentage, and the balance is magnesium and inevitable impurities. Or, the Mg-Gd-Y-Zn-Mn alloy comprises 1.58% of Gd, 1.24% of Y, 2.82% of Zn and 0.50% of Mn in terms of atomic percentage, and the balance is magnesium and inevitable impurities.

3. The method of claim 1, wherein, The Mg-Gd-Y-Zn-Mn alloy comprises 8.89% of Gd, 3.95% of Y, 3.30% of Zn and 0.98% of Mn in terms of mass percentage, and the balance is magnesium and inevitable impurities. Or, the Mg-Gd-Y-Zn-Mn alloy comprises 1.58% of Gd, 1.24% of Y, 1.41% of Zn and 0.50% of Mn in terms of atomic percentage, and the balance is magnesium and inevitable impurities.

4. The method of claim 1, wherein, The Mg-Gd-Y-Zn-Mn alloy comprises 8.67% of Gd, 3.85% of Y, 6.43% of Zn and 1.92% of Mn in terms of mass percentage, and the balance is magnesium and inevitable impurities. Or, the Mg-Gd-Y-Zn-Mn alloy comprises 1.58% of Gd, 1.24% of Y, 2.82% of Zn and 1.0% of Mn in terms of atomic percentage, and the balance is magnesium and inevitable impurities.

5. The method of claim 1, wherein, The Mg-Gd-Y-Zn-Mn alloy comprises 8.84% of Gd, 3.92% of Y, 3.28% of Zn and 1.96% of Mn in terms of mass percentage, and the balance is magnesium and inevitable impurities. Or, the Mg-Gd-Y-Zn-Mn alloy comprises 1.58% of Gd, 1.24% of Y, 1.41% of Zn and 1.0% of Mn in terms of atomic percentage, and the balance is magnesium and inevitable impurities.

6. The method of claim 1, wherein, The raw materials comprise pure Mg, pure Zn, Mg-Gd intermediate alloy containing 25wt%-30wt% of Gd, Mg-Y intermediate alloy containing 25wt%-30wt% of Y and Mg-Mn intermediate alloy containing 5wt%-10wt% of Mn.

7. The method of claim 1, wherein, The rapid solidification is carried out in a vacuum spinning machine, and the circumferential speed of the copper roller is not less than 5 m / s during the spinning process.

8. The method of claim 1, wherein, The artificial aging treatment is carried out at a temperature of 150-250 DEG C.

9. The method of claim 1, wherein, P2 >= 98%P1.

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