CN109161769A - A kind of functional quickly solvable rare earth magnesium alloy material and preparation method thereof - Google Patents

Abstract

The invention discloses a functional fast soluble rare earth magnesium alloy material and a preparation method thereof, belonging to the field of non-ferrous metals. The magnesium alloy is composed of Mg _a Gd _b Y _c Zr _d Ni _e M _f N _g , wherein M is one or a combination of two elements in Ga and In elements, and N is Al, Mn, Ca, Zn, Cu , Sn, Sr, Li, La, Ce, Pr, Nd, Ge, Ag, Si and other elements in any combination of one or more, through smelting casting, solution treatment, hot extrusion and aging treatment to obtain the target alloy . Compared with the prior art, the magnesium alloy material prepared by using the composition of the present invention has higher strength and plasticity, and can be rapidly dissolved in a solution containing electrolyte, and is suitable for processing seals used in the fracturing process of oil and gas fields. Blocking tools, the tools can be dissolved by themselves after the service is completed, eliminating the subsequent flowback and milling processes, and improving the construction efficiency.

Description

A functional fast soluble rare earth magnesium alloy material and preparation method thereof

technical field

The invention belongs to the field of non-ferrous metals, in particular to a functional fast soluble rare earth magnesium alloy material and a preparation method thereof.

Background technique

As one of the lightest commercial metal structural materials, magnesium alloys have a series of advantages such as low density, high specific strength, high specific stiffness, good electromagnetic shielding ability, machinability and easy recycling. , automotive, electronics and other fields are widely used. On the other hand, magnesium alloys have lower electrode potential, more active chemical properties, and are prone to corrosion in most solutions, which can be used in specific industrial fields. However, the corrosion rate of magnesium alloys at room temperature is not high, which cannot meet the needs of industrial applications. It is of great significance to improve the corrosion rate of magnesium alloys by alloying methods.

China is rich in low-permeability oil and gas resources and has great potential for exploration and development. In the future, stable and increased oil and gas production will rely more on these low-permeability unconventional oil and gas resources. Most of these oil and gas resources are distributed in strata of different depths, and the development of these unconventional oil and gas resources must rely on reservoir stimulation technologies such as hydraulic fracturing. In hydraulic fracturing technology, isolation tools (such as fracturing balls and bridge plugs) are used to separate the different layers, and then fracturing is carried out layer by layer. Open the well to realize the exploitation of oil and gas.

At present, most of the commonly used isolation tools are made of steel, which has disadvantages such as difficulty in drilling and milling, time-consuming, and difficult flowback of powder and fragments after drilling. Therefore, composite materials have been developed. Although the problem of large proportion is solved, there is a problem of easy blocking of channels because it cannot be completely dissolved, and the production and processing of raw materials need to be imported, which is expensive.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a functional rapidly soluble rare earth magnesium alloy material to ensure that it has excellent mechanical properties and can achieve rapid dissolution in a corresponding solution.

A functional fast soluble rare earth magnesium alloy material, the magnesium alloy composition is Mg _a Gd _b Y _c Zr _d Ni _e M _f N _g , wherein M is one of Ga, In elements or a combination of two elements , N is one or any combination of more than one of Al, Mn, Ca, Zn, Cu, Sn, Sr, Li, La, Ce, Pr, Nd, Ge, Ag, Si and other elements.

In the formula Mg _a Gd _b Y _c Zr _d Ni _e M _f N _g , the weight percentage of b is 0.1-15%, the weight percentage of c is 0.1-10%, the weight percentage of d is 0.1-5%, and the weight percentage of e is 0.1-5%. The percentage is 0.1-10%, the weight percentage of f is 0.1-10%, the weight percentage of g is 0-20%, a is the balance, a+b+c+d+e+f+g=100.

The above-mentioned preparation method of a functional fast soluble rare earth magnesium alloy material, comprising the following steps:

(1) Pretreatment: Weigh the required raw materials by weight percentage, and polish off the oxide layer on the metal surface with sandpaper.

(2) smelting and casting: put the pretreated raw materials into a graphite crucible, heat and melt in a resistance furnace, stir and mix evenly, and obtain an ingot after casting;

(3) homogenization treatment: the obtained ingot is kept at a certain temperature for a period of time;

(4) hot extrusion: the obtained ingot is subjected to hot extrusion at a certain temperature to obtain an alloy rod;

(5) Aging treatment: The alloy rod obtained by extrusion is subjected to aging treatment at a certain temperature.

Further, in the smelting and casting process of step (2), pure magnesium is first added to the crucible for melting, and SF ₆ +CO ₂ gas protection is required during the melting process, and then the melt temperature is raised to 700-710 ° C and other pure metals are added. And the intermediate alloy, stir and slag after all melted, raise the melt temperature to 730-750℃, keep the temperature for 10-30min, and then lower the temperature to 700-710℃ for casting. The casting mold adopts a water-cooled copper mold.

Further, in step (3), the homogenization treatment is performed, and the temperature range of the heat preservation temperature is 400-530° C., and the time is 10-40 h.

Further, in the hot extrusion process of step (4), the extrusion temperature is 350-450° C., and the total deformation amount is 60-90%.

Further, in step (5) aging treatment, the temperature range is 160-250°C, and the time is 10-200h.

The invention aims to provide a functional new type of dissolvable magnesium alloy material, which has high strength, good plasticity, rapid dissolution, and can be widely used in the field of oil exploitation. Compared with steel and composite materials, it can be completely dissolved, there is no easy blocking problem, there is no secondary drilling problem, and it can reduce production costs. It is mainly used in fracturing downhole tool components, such as fracturing balls, ball seats, Packers, bridge plugs, etc.

Compared with the prior art, the magnesium alloy material prepared by the invention has high mechanical strength, good plasticity, can realize rapid dissolution in salt solution, and is suitable for processing plugging tools used in the fracturing process of oil and gas fields. After the service is completed, it dissolves on its own, eliminating the subsequent flowback and milling processes and improving the construction efficiency.

Description of drawings

Fig. 1 is the typical microstructure morphology of the alloys in Examples 1 and 2;

Fig. 2 is the tensile curve diagram of the alloy among the embodiment 1-4;

Fig. 3 is the corrosion rate comparison diagram of alloy in embodiment 1-4;

Detailed ways

The following examples will further illustrate the invention.

Example 1: Mg-10Gd-3Y-0.3Zr-0.2Ni-0.1In alloy

Weigh the required alloy raw materials in proportion, and polish the surface of the alloy. The alloys were added to the crucible one by one for melting, kept at 750 °C for 10 min, and then cooled to 710 °C for casting. The casting mold was a water-cooled copper mold. Subsequently, the ingot was homogenized, and the holding temperature was 520° C. and the time was 10 h. The homogenized ingot was processed into a cylinder for extrusion processing, the extrusion temperature was 420° C., the extrusion speed was 0.4 mm/s, and the extrusion ratio was 16. After extrusion, the bar is subjected to aging treatment at a temperature of 225°C and a time of 12h.

The room temperature tensile strength of the Mg-10Gd-3Y-0.3Zr-0.2Ni-0.1In alloy obtained by the above steps is 320.6 MPa, the yield strength is 259.1 MPa, and the elongation at break is as high as 13.4%. At room temperature, in 3% KCl solution The corrosion rate is 37.6 mg/cm ² /h, and at 90 °C, the corrosion rate in 3% KCl solution is 67.8 mg/cm ² /h, which can be dissolved by itself.

Example 2: Mg-9Gd-3Y-0.1Zr-0.8Ni-0.1In alloy

Weigh the required alloy raw materials in proportion, and polish the surface of the alloy. The alloys were added to the crucible one by one for melting, kept at 750 °C for 10 min, and then cooled to 710 °C for casting. The casting mold was a water-cooled copper mold. Subsequently, the ingot was homogenized, and the holding temperature was 520° C. and the time was 10 h. The homogenized ingot was processed into a cylinder for extrusion processing, the extrusion temperature was 420° C., the extrusion speed was 0.4 mm/s, and the extrusion ratio was 16. After extrusion, the bar is subjected to aging treatment at a temperature of 225°C and a time of 12h.

The room temperature tensile strength of the Mg-9Gd-3Y-0.1Zr-0.8Ni-0.1In alloy obtained by the above steps is 363.1 MPa, the yield strength is 289.3 MPa, and the elongation at break is as high as 11.2%. At room temperature, in 3% KCl solution The corrosion rate is 22.8 mg/cm ² /h, and at 90 °C, the corrosion rate in 3% KCl solution is 41.4 mg/cm ² /h, which can be dissolved by itself.

Example 3: Mg-10Gd-3Y-0.25Zr-0.4Ni-0.1Ga alloy

Weigh the required alloy raw materials in proportion, and polish the surface of the alloy. The alloys were added to the crucible one by one for melting, kept at 750 °C for 10 min, and then cooled to 710 °C for casting. The casting mold was a water-cooled copper mold. Subsequently, the ingot was homogenized, and the holding temperature was 520° C. and the time was 10 h. The homogenized ingot was processed into a cylinder for extrusion processing, the extrusion temperature was 420° C., the extrusion speed was 0.4 mm/s, and the extrusion ratio was 16. After extrusion, the bar is subjected to aging treatment at a temperature of 225°C and a time of 12h.

The room temperature tensile strength of the Mg-10Gd-3Y-0.25Zr-0.4Ni-0.1Ga alloy obtained by the above steps is 319.9 MPa, the yield strength is 255.5 MPa, and the elongation at break is as high as 12.6%. The corrosion rate is 16.3 mg/cm ² /h, and at 90 °C, the corrosion rate in 3% KCl solution is 32.3 mg/cm ² /h, which can be dissolved by itself.

Example 4: Mg-9Gd-3Y-0.2Zr-0.6Ni-0.1In-0.3Zn alloy

Weigh the required alloy raw materials in proportion, and polish the surface of the alloy. The alloys were added to the crucible one by one for melting, kept at 750 °C for 10 min, and then cooled to 710 °C for casting. The casting mold was a water-cooled copper mold. Subsequently, the ingot was homogenized, and the holding temperature was 520° C. and the time was 10 h. The homogenized ingot was processed into a cylinder for extrusion processing, the extrusion temperature was 420° C., the extrusion speed was 0.4 mm/s, and the extrusion ratio was 16. After extrusion, the bar is subjected to aging treatment at a temperature of 225°C and a time of 12h.

The room temperature tensile strength of the Mg-9Gd-3Y-0.2Zr-0.6Ni-0.1In-0.3Zn alloy obtained by the above steps is 360.9 MPa, the yield strength is 270.2 MPa, and the elongation at break is as high as 10.1%. The corrosion rate in KCl solution is 10.2 mg/cm ² /h, and at 90°C, the corrosion rate in 3% KCl solution is 22.7 mg/cm ² /h, which can be dissolved by itself.

Example 5: Mg-9Gd-3Y-0.2Zr-0.6Ni-0.1In-0.5Cu alloy

Weigh the required alloy raw materials in proportion, and polish the surface of the alloy. The alloys were added to the crucible one by one for melting, kept at 750 °C for 10 min, and then cooled to 710 °C for casting. The casting mold was a water-cooled copper mold. Subsequently, the ingot was homogenized, and the holding temperature was 520° C. and the time was 10 h. The homogenized ingot was processed into a cylinder for extrusion processing, the extrusion temperature was 420° C., the extrusion speed was 0.4 mm/s, and the extrusion ratio was 16. After extrusion, the bar is subjected to aging treatment at a temperature of 225°C and a time of 12h.

The room temperature tensile strength of the Mg-9Gd-3Y-0.2Zr-0.6Ni-0.1In-0.3Zn alloy obtained by the above steps is 370.9 MPa, the yield strength is 282.2 MPa, and the elongation at break is as high as 11.9%. The corrosion rate in KCl solution is 15.2 mg/cm ² /h, and at 90°C, the corrosion rate in 3% KCl solution is 33.7 mg/cm ² /h, which can be dissolved by itself.

The embodiments described in the present invention are only examples used to clearly illustrate the present invention, and are not intended to limit the embodiments of the present invention. For those of ordinary skill in the art, other changes in different forms can also be made on the basis of the above description, and relevant changes are all within the protection scope of the claims of the present invention.

Claims (6)

1. a functional fast soluble rare earth magnesium alloy material, it is characterized in that described magnesium alloy composition is Mg _a Gd _b Y _c Zr _d Ni _e M _f N _g , wherein M is a kind of in Ga, In element or The combination of two elements, N is any combination of one or more of Al, Mn, Ca, Zn, Cu, Sn, Sr, Li, La, Ce, Pr, Nd, Ge, Ag, Si elements; formula In Mg _a Gd _b Y _c Zr _d Ni _e M _f N _g , the weight percentage of b is 0.1-15%, the weight percentage of c is 0.1-10%, the weight percentage of d is 0.1-5%, and the weight percentage of e is 0.1-10%, the weight percentage of f is 0.1-10%, the weight percentage of g is 0-20%, a is the balance, a+b+c+d+e+f+g=100. 2. the preparation method of a kind of functional fast soluble rare earth magnesium alloy material as claimed in claim 1, is characterized in that, preparation step is as follows: (1) Pretreatment: Weigh the required raw materials by weight percentage, and polish off the oxide layer on the metal surface with sandpaper. (2) smelting and casting: put the pretreated raw materials into a graphite crucible, heat and melt in a resistance furnace, stir and mix evenly, and obtain an ingot after casting; (3) homogenization treatment: the obtained ingot is kept at a certain temperature for a period of time; (4) hot extrusion: the obtained ingot is subjected to hot extrusion at a certain temperature to obtain an alloy rod; (5) Aging treatment: The alloy rod obtained by extrusion is subjected to aging treatment at a certain temperature. 3. the preparation method of a kind of functional fast soluble rare earth magnesium alloy material as claimed in claim 2 is characterized in that: the described melting and casting process of step (2) is: first pure magnesium is added in the crucible to melt, During the melting process, SF ₆ +CO ₂ gas protection is required, and then the melt temperature is raised to 700-710 ℃, and other pure metals and intermediate alloys are added. After all melting, stirring and slag removal are performed, and the melt temperature is raised to 730 -750°C, keep the temperature for 10-30min, and then cool down to 700-710°C for casting. The casting mold adopts a water-cooled copper mold. 4 . The preparation method of a functional fast soluble rare earth magnesium alloy material according to claim 2 , wherein the homogenization treatment in step (3) is that the temperature range of the holding temperature is 400-530° C., and the time 10-40h. 5. The preparation method of a functional fast soluble rare earth magnesium alloy material according to claim 2, wherein the hot extrusion process of step (4) is, the extrusion temperature is 350-450 DEG C, The total deformation is 60-90%. 6 . The preparation method of a functional fast soluble rare earth magnesium alloy material according to claim 2 , wherein the aging treatment in step (5) is that the temperature range is 160-250° C., and the time is 10- 200h.