A continuous solid-state recovery method for alloy chips

Abstract

The present invention proposes a method for continuous solid-state recovery of alloy chips, which belongs to the field of metal plastic processing technology. The method of the present invention includes four steps: blank preparation, chip hot pressing and sintering, hot extrusion, and quenching treatment of formed parts. The three independent steps of chip hot pressing and sintering, hot extrusion, and heat treatment are integrated into a continuous and efficient forming process. The heating temperature of the chip hot pressing and sintering step is 250-350℃, the holding time is 5min, and the pressure is 200MPa. Real-time heat treatment promotes dynamic recrystallization to obtain a fine grain structure, while improving the recovery rate of lightweight alloys such as magnesium-lithium alloys. The continuous solid-state recovery process of alloy chips of the present invention is carried out in a hot pressing and sintering device. The whole process does not require secondary heating, and only the hot extrusion die needs to be replaced. The resulting formed parts show higher comprehensive mechanical properties, simple process, and high recovery rate.

Description

Technical Field

[0001] The invention belongs to the technical field of metal plastic processing, and in particular relates to a method for continuous solid-state recovery of alloy chips. Background Art

[0002] In recent years, the lightweight manufacturing industry has developed rapidly. Magnesium-lithium alloys, due to their low density, high specific strength and stiffness, and excellent corrosion resistance, have been widely used in high-end lightweight manufacturing fields such as aerospace and consumer electronics. However, with the expansion of these applications, the amount of waste generated by machining has also increased significantly. Currently, the regeneration of magnesium-lithium alloy waste mainly relies on remelting and refining. However, due to the high oxidability of magnesium-lithium alloys, a large amount of lithium is lost during the remelting process, resulting in a recovery rate of less than 50%, high recycling costs, and increased environmental pollution.

[0003] Current commercially available solid-state recycling methods for alloy chips typically require a series of independent steps: cold compaction, hot pressing and sintering, thermal deformation, and heat treatment. Each step requires mold replacement, and the hot pressing and thermal deformation processes require secondary heating. Furthermore, after thermal deformation, the formed parts must be removed while still hot for heat treatment. This cumbersome and difficult process makes it unsuitable for industrial production. Summary of the Invention

[0004] To address the aforementioned technical issues, the present invention proposes a continuous solid-state recovery method for alloy chips. This method eliminates the cold pressing step in traditional solid-state recovery processes and directly recovers alloy chips through a hot pressing, sintering, and hot extrusion process. This hot pressing, sintering, and hot extrusion process only requires the replacement of the corresponding extrusion die and gasket, without replacing the main die, thus avoiding the need for repeated die heating. Furthermore, a heat treatment die is installed below the extrusion die. Coolant, passing through a circulation channel within the die, can directly act on the formed part, achieving real-time heat treatment.

[0005] To achieve the above objectives, the present invention provides a continuous solid-state recovery method for alloy chips, which includes four steps: billet preparation, chip hot pressing and sintering, hot extrusion, and quenching treatment of formed parts. The three independent steps of chip hot pressing and sintering, hot extrusion, and heat treatment are integrated into a continuous and efficient forming process. The heating temperature of the chip hot pressing and sintering step is 250-350°C, the holding time is 5 minutes, and the pressure is 200 MPa.

[0006] Furthermore, the hot extrusion temperature is 300° C. and the holding time is 3 minutes.

[0007] Furthermore, the extrusion speed of the hot extrusion is 0.1 mm / s.

[0008] Furthermore, the continuous solid-state recovery process of alloy chips is carried out in a hot pressing and sintering device, which includes a punch, an extrusion barrel, a pad and a heating ring. The diameter of the punch is the same as the inner diameter of the extrusion barrel, and the punch moves up and down inside the extrusion barrel. The pad is located at the bottom of the extrusion barrel, the inner diameter of the heating ring is the same as the outer diameter of the extrusion barrel, and the heating ring is located outside the extrusion barrel. The pad of the hot pressing and sintering device is a detachable device. The hot pressing and sintering device is used for the hot pressing and sintering process of chips. After the hot pressing and sintering process of chips is completed, it is only necessary to remove the pad of the hot pressing and sintering device and replace it with an extrusion die. The heat treatment die is connected to the bottom of the extrusion die through a connecting fixture. A circulation channel is provided on the heat treatment die. The coolant can directly act on the formed part through the circulation channel without affecting the temperature of the extrusion die. Specifically, the following steps are included:

[0009] 1) collecting alloy chips generated during machining, ultrasonically cleaning the alloy chips in alcohol, and then drying them for later use;

[0010] 2) placing the cleaned alloy chips in the extrusion barrel of the hot pressing and sintering device, and hot pressing and sintering the chips by heating the heating ring;

[0011] 3) While the chips are hot pressed and sintered, the extrusion die used for the hot extrusion process is placed in a heating furnace for heating;

[0012] 4) After the hot pressing and sintering of the chips is completed, the backing plate in the hot pressing and sintering device is removed, and the extrusion die heated in step 3) is inserted into the extrusion barrel of the hot pressing and sintering device, and heated and kept warm;

[0013] 5) The heat treatment die is installed under the extrusion die through the connecting fixture for hot extrusion, and the coolant is introduced through the circulation channel for quenching;

[0014] 6) The alloy chips are deformed by hot extrusion to form continuous solid-state recycling parts;

[0015] 7) Take out the continuous solid-state recovery formed parts to achieve continuous solid-state recovery of alloy chips.

[0016] Furthermore, in step 3), the extrusion die used for the hot extrusion device is placed in a heating furnace and heated to 300°C.

[0017] Furthermore, in step 2), the heating rate of the heating ring is 40°C / min.

[0018] Furthermore, in step 4), the heating and insulation temperature is 300° C. and the time is 3 minutes.

[0019] Compared with the prior art, the present invention has the following advantages and technical effects:

[0020] (1) The present invention destroys the surface oxide film of alloy chips through a hot pressing sintering-hot extrusion strong plastic deformation process, achieving forced solidification and bonding of the newly formed surface. Real-time heat treatment promotes dynamic recrystallization to obtain a fine grain structure, while simultaneously improving the recovery rate of lightweight alloys such as magnesium-lithium alloys. The performance of the formed parts reaches or even exceeds that of columnar billets, reducing recycling costs. By comparison, the mechanical properties of the formed parts prepared by the alloy chip recycling method of the present invention are comparable to or even slightly exceed those of traditional solid-state recycled formed parts. The method of the present invention is more suitable for the recycling and reuse of light alloy chips such as magnesium alloys and aluminum alloys.

[0021] (2) The continuous solid-state recovery method for alloy chips of the present invention eliminates the cold compaction process in the traditional solid-state recovery process and directly recovers the alloy chips through hot pressing and sintering-hot extrusion. The entire process does not require secondary heating, and only the hot extrusion die needs to be replaced. The hot extrusion die is connected to the hot extrusion die through a connecting fixture, and the formed part can be directly quenched after extrusion through the circulation pipeline on the heat treatment die. The three independent steps of hot pressing and sintering-hot extrusion-heat treatment in the solid-state recovery process are integrated into a continuous and efficient forming process, effectively simplifying the forming steps and shortening the forming time. The resulting formed part exhibits higher comprehensive mechanical properties. In addition, the process is simple, has a high recovery rate, does not produce harmful gases, and can effectively save resources, reduce energy consumption, and reduce environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0023] Figure 1 The figure is a flow chart of a continuous solid-state recovery method for alloy chips according to the present invention, wherein: 1 is alloy chips; 2 is alcohol; 3 is a punch; 4 is an extrusion cylinder; 5 is a backing plate; 6 is a heating ring; 7 is an extrusion die; 8 is a continuous solid-state recovery forming part; 9 is a connecting attachment; 10 is a circulation channel; 11 is a heat treatment die;

[0024] Figure 2 This is a schematic diagram of the solid-state recovery process of traditional alloy chips in Comparative Example 1;

[0025] Figure 3 Schematic diagram of chip recovery process at different hot pressing sintering temperatures in Examples 1-3;

[0026] Figure 4The metallographic images and SEM images of the continuous solid-state recycling molded part prepared in Example 1 and the original LA103Z ultralight magnesium-lithium alloy chips, wherein (a) is the metallographic image of the LA103Z ultralight magnesium-lithium alloy chips, (b) is the metallographic image of the continuous solid-state recycling molded part prepared in Example 1, (c) is the SEM image of the LA103Z ultralight magnesium-lithium alloy chips, and (d) is the SEM image of the continuous solid-state recycling molded part prepared in Example 1;

[0027] Figure 5 The mechanical properties of Examples 1-3 and the prepared formed parts and cylindrical billets are measured, wherein (a) is the ultimate tensile strength (UTS) measurement result of each formed part, and (b) is the ultimate tensile strength (UTS), yield strength (YS), and deformation (Elongation) measurement result of each formed part;

[0028] Figure 6 The strain-stress curve results of the formed part prepared in Comparative Example 1;

[0029] Figure 7 The strain-stress curve results of the formed parts (S1, S2) prepared in Comparative Examples 2 and 3 are shown;

[0030] Figure 8 The strain stress curve results of the formed part prepared in Comparative Example 4 are shown. DETAILED DESCRIPTION

[0031] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0032] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also encompassed by the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0033] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0034] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be illustrative only.

[0035] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0036] An embodiment of the present invention provides a continuous solid-state recovery method for alloy chips, including four steps: billet preparation, chip hot pressing and sintering, hot extrusion, and quenching treatment of formed parts. The three independent steps of chip hot pressing and sintering, hot extrusion, and heat treatment are integrated into a continuous and efficient forming process. The heating temperature of the chip hot pressing and sintering step is 250-350°C, the holding time is 5 minutes, and the pressure is 200 MPa.

[0037] In a preferred embodiment of the present invention, the temperature of the hot extrusion is 300° C. and the holding time is 3 minutes.

[0038] In a preferred embodiment of the present invention, the extrusion speed of the hot extrusion is 0.1 mm / s.

[0039] In a preferred embodiment of the present invention, the continuous solid-state recovery process of alloy chips is carried out in a hot pressing and sintering device, which includes a punch, an extrusion barrel, a pad and a heating ring. The diameter of the punch is the same as the inner diameter of the extrusion barrel, and the punch moves up and down inside the extrusion barrel. The pad is located at the bottom of the extrusion barrel, the inner diameter of the heating ring is the same as the outer diameter of the extrusion barrel, and the heating ring is located outside the extrusion barrel. The pad of the hot pressing and sintering device is a detachable device used for the hot pressing and sintering process of chips. After the hot pressing and sintering process of chips is completed, it is only necessary to remove the pad of the hot pressing and sintering device and replace it with an extrusion die. The heat treatment die is connected to the bottom of the extrusion die through a connecting fixture. A circulation channel is provided on the heat treatment die. The coolant can directly act on the formed part through the circulation channel without affecting the temperature of the extrusion die. Specifically, the following steps are included:

[0040] 1) collecting alloy chips generated during machining, ultrasonically cleaning the alloy chips in alcohol, and then drying them for later use;

[0041] 2) placing the cleaned alloy chips in the extrusion barrel of the hot pressing and sintering device, and hot pressing and sintering the chips by heating the heating ring;

[0042] 3) While the chips are hot pressed and sintered, the extrusion die used for the hot extrusion process is placed in a heating furnace for heating;

[0043] 4) After the hot pressing and sintering of the chips is completed, the backing plate in the hot pressing and sintering device is removed, and the extrusion die heated in step 3) is inserted into the extrusion barrel of the hot pressing and sintering device and kept warm;

[0044] 5) The heat treatment die is installed under the extrusion die through the connecting fixture for hot extrusion, and the coolant is introduced through the circulation channel for quenching;

[0045] 6) The alloy chips are deformed by hot extrusion to form continuous solid-state recycling parts;

[0046] 7) Take out the continuous solid-state recovery formed parts to achieve continuous solid-state recovery of alloy chips.

[0047] In a preferred embodiment of the present invention, in step 3), the extrusion die used for the hot extrusion device is placed in a heating furnace and heated to 300°C.

[0048] In a preferred embodiment of the present invention, in step 2), the heating rate of the heating ring is 40° C. / min.

[0049] In a preferred embodiment of the present invention, in step 4), the heating and heat preservation temperature is 300° C. and the time is 3 minutes.

[0050] A schematic flow diagram of a continuous solid state recovery method for alloy chips according to an embodiment of the present invention is shown in FIG. Figure 1 , where: 1 is alloy chips; 2 is alcohol; 3 is punch; 4 is extrusion cylinder; 5 is backing plate; 6 is heating ring; 7 is extrusion die; 8 is continuous solid recovery forming part; 9 is connecting attachment; 10 is circulation channel; 11 is heat treatment die, specifically:

[0051] 1) collecting alloy chips 1 generated during machining, ultrasonically cleaning the alloy chips in alcohol 2 for 5 minutes, and then drying them for later use;

[0052] 2) The cleaned alloy chips 1 are placed in the extrusion barrel 4 of the hot pressing sintering device. The heating ring 6 heats the hot pressing sintering device to 250-350°C at a heating rate of 40°C / min, and then the temperature is kept at this temperature for 5 minutes to perform hot pressing sintering of the chips. The hot pressing sintering process is carried out at a pressure of 200 MPa.

[0053] 3) While the chips are being hot pressed and sintered, the extrusion die 7 used for the hot extrusion process is placed in a heating furnace and heated to 300°C for insulation;

[0054] 4) After the chips are hot pressed and sintered for 5 minutes, the backing plate 5 in the hot pressing and sintering device is removed, and the extrusion die 7 heated in step 3) is inserted into the extrusion barrel 4 of the hot pressing and sintering device and kept at 300°C for 3 minutes;

[0055] 5) Install the heat treatment die 11 below the extrusion die 7 through the connecting fixture 9, set the extrusion press parameters, control the punch 3 to perform hot extrusion at a speed of 0.1 mm / s, and at the same time, pass coolant (water) through the circulation channel 10 for quenching;

[0056] 6) The alloy chips are deformed by hot extrusion, and the surface oxide film is destroyed, so that the new surface is forced to solidify and bond, forming a continuous solid recovery formed part 8. The coolant (water) passes through the circulation channel 10 and is directly and evenly sprayed on the continuous solid recovery formed part 8 to achieve real-time quenching of the formed part;

[0057] 7) Taking out the continuous solid-state recovery formed part 8 to realize the continuous solid-state recovery of alloy chips.

[0058] In the embodiment of the present invention, the alloy chips used are LA103Z ultralight magnesium-lithium alloy chips, and the coolant used is water at room temperature.

[0059] The technical solution of the present invention is further illustrated by the following examples.

[0060] Example 1

[0061] A method for continuous solid-state recovery of alloy chips according to an embodiment of the present invention specifically comprises the following steps:

[0062] 1) Collecting LA103Z ultralight magnesium-lithium alloy chips generated during machining, ultrasonically cleaning the alloy chips in alcohol for 5 minutes, and then drying them for later use;

[0063] 2) The cleaned alloy chips were placed in the extrusion barrel of the hot pressing sintering device. The heating ring was used to heat the hot pressing sintering device to 250°C at a heating rate of 40°C / min. The chips were then hot pressed and sintered for 5 minutes. The hot pressing sintering process was carried out at a pressure of 200 MPa.

[0064] 3) While the chips are hot pressed and sintered, the extrusion die used for the hot extrusion process is placed in a heating furnace and heated to 300°C for insulation;

[0065] 4) After the chips are hot-pressed and sintered for 5 minutes, the backing plate in the hot-pressing and sintering device is removed, and the extrusion die heated in step 3) is inserted into the extrusion barrel of the hot-pressing and sintering device and kept at 300°C for 3 minutes;

[0066] 5) Install the heat treatment die under the extrusion die through the connecting fixture, set the extrusion press parameters, control the punch to perform hot extrusion at a speed of 0.1 mm / s, and at the same time, pass coolant (water) through the circulation channel for quenching;

[0067] 6) The alloy chips are deformed by hot extrusion, and the surface oxide film is destroyed, so that the new surface is forced to solidify and bond, forming a continuous solid recovery formed part. The coolant (water) passes through the circulation channel and is directly and evenly sprayed on the continuous solid recovery formed part to achieve real-time quenching of the formed part;

[0068] 7) Taking out the continuous solid-state recovery molded part to achieve continuous solid-state recovery of alloy chips, and the obtained continuous solid-state recovery molded part is recorded as CS1.

[0069] Example 2

[0070] A method for continuous solid-state recovery of alloy chips according to an embodiment of the present invention specifically comprises the following steps:

[0071] 1) Collecting LA103Z ultralight magnesium-lithium alloy chips generated during machining, ultrasonically cleaning the alloy chips in alcohol for 5 minutes, and then drying them for later use;

[0072] 2) The cleaned alloy chips were placed in the extrusion barrel of the hot pressing sintering device. The heating ring was used to heat the hot pressing sintering device to 300°C at a heating rate of 40°C / min. The chips were then hot pressed and sintered for 5 minutes. The hot pressing sintering process was carried out at a pressure of 200 MPa.

[0073] 3) While the chips are hot pressed and sintered, the extrusion die used for the hot extrusion process is placed in a heating furnace and heated to 300°C for insulation;

[0074] 4) After the chips are hot-pressed and sintered for 5 minutes, the backing plate in the hot-pressing and sintering device is removed, and the extrusion die heated in step 3) is inserted into the extrusion barrel of the hot-pressing and sintering device and kept at 300°C for 3 minutes;

[0075] 5) Install the heat treatment die under the extrusion die through the connecting fixture, set the extrusion press parameters, control the punch to perform hot extrusion at a speed of 0.1 mm / s, and at the same time, pass coolant (water) through the circulation channel for quenching;

[0076] 6) The alloy chips are deformed by hot extrusion, and the surface oxide film is destroyed, so that the new surface is forced to solidify and bond, forming a continuous solid recovery formed part. The coolant (water) passes through the circulation channel and is directly and evenly sprayed on the continuous solid recovery formed part to achieve real-time quenching of the formed part;

[0077] 7) Taking out the continuous solid-state recovery molded part to achieve continuous solid-state recovery of alloy chips, and the obtained continuous solid-state recovery molded part is recorded as CS2.

[0078] Example 3

[0079] A method for continuous solid-state recovery of alloy chips according to an embodiment of the present invention specifically comprises the following steps:

[0080] 1) Collecting LA103Z ultralight magnesium-lithium alloy chips generated during machining, ultrasonically cleaning the alloy chips in alcohol for 5 minutes, and then drying them for later use;

[0081] 2) The cleaned alloy chips were placed in the extrusion barrel of the hot pressing sintering device. The heating ring was used to heat the hot pressing sintering device to 350°C at a heating rate of 40°C / min. The chips were then hot pressed and sintered for 5 minutes. The hot pressing sintering process was carried out under a pressure of 200 MPa.

[0082] 3) While the chips are hot pressed and sintered, the extrusion die used for the hot extrusion process is placed in a heating furnace and heated to 300°C for insulation;

[0083] 4) After the chips are hot-pressed and sintered for 5 minutes, the backing plate in the hot-pressing and sintering device is removed, and the extrusion die heated in step 3) is inserted into the extrusion barrel of the hot-pressing and sintering device and kept at 300°C for 3 minutes;

[0084] 5) Install the heat treatment die under the extrusion die through the connecting fixture, set the extrusion press parameters, control the punch to perform hot extrusion at a speed of 0.1 mm / s, and at the same time, pass coolant (water) through the circulation channel for quenching;

[0085] 6) The alloy chips are deformed by hot extrusion, and the surface oxide film is destroyed, so that the new surface is forced to solidify and bond, forming a continuous solid recovery formed part. The coolant (water) passes through the circulation channel and is directly and evenly sprayed on the continuous solid recovery formed part to achieve real-time quenching of the formed part;

[0086] 7) Taking out the continuous solid-state recovery molded part to achieve continuous solid-state recovery of alloy chips, and the obtained continuous solid-state recovery molded part is recorded as CS3.

[0087] Comparative Example 1

[0088] The schematic diagram of the traditional alloy chip solid state recovery process is shown in Figure 2 .

[0089] Chip recovery is carried out using the steps of cold compaction - hot pressing sintering - hot deformation - heat treatment. The steps are as follows:

[0090] 1) Collect LA103Z ultralight magnesium-lithium alloy chips generated during machining, ultrasonically clean the chips in alcohol for 5 minutes, and then dry them for later use;

[0091] 2) Place the dried chips in a cold compaction mold and cold press them at a pressure of 200 MPa for 5 minutes before removing them;

[0092] 3) The cold compacted blank was placed in the extrusion barrel of the hot pressing and sintering device. The heating ring heated the hot pressing and sintering device to 300°C at 40°C / min and then kept at this temperature for 5 minutes. During this process, the chips were hot compressed at a pressure of 200 MPa.

[0093] 4) After the chip blank is cooled, take out the hot pressed sintered blank and place it in a hot extrusion die. Heat the hot extrusion die to 300°C and keep it warm for 3 minutes.

[0094] 5) Setting the extrusion press parameters, controlling the punch to perform hot extrusion at a speed of 0.1 mm / s, and obtaining chip recovery formed parts;

[0095] 6) Take out the formed part and place it in water for quenching.

[0096] Schematic diagram of chip recovery process at different hot pressing sintering temperatures in Example 1-3 is shown in Figure 3 .

[0097] The metallographic images and SEM images of the continuous solid-state recycling molded parts and the original LA103Z ultralight magnesium-lithium alloy chips prepared in Example 1 are shown in Figure 4 , wherein (a) is a metallographic image of LA103Z ultralight magnesium-lithium alloy chips, (b) is a metallographic image of the continuous solid-state recycling molded part prepared in Example 1, (c) is a SEM image of LA103Z ultralight magnesium-lithium alloy chips, and (d) is a SEM image of the continuous solid-state recycling molded part prepared in Example 1. Figure 4 It can be seen that the microstructure of the formed part obtained by the recycling method of the embodiment of the present invention does not show obvious cracks and defects, the grain size is reduced from the original 15.4μm to 7.8μm, and a large amount of AlLi and MgLi2Al are precipitated in the solid-state recycled formed part. These hard precipitated phases are beneficial to improving the mechanical properties of the solid-state recycled formed part.

[0098] Preparation of columnar billets: Magnesium-lithium alloy extrusion billets are processed into columnar billets with a diameter of 36 mm, and then hot extruded to obtain formed parts, namely the columnar billets described below.

[0099] The mechanical properties of the prepared parts and columnar blanks are shown in Table 1-3. Figure 5, where (a) is the ultimate tensile strength (UTS) measurement result of each formed part, and (b) is the ultimate tensile strength, yield strength, and elongation measurement result of each formed part. It can be seen that the formed part (CS2) obtained in Example 2 has a tensile strength of 211 MPa and a yield strength of 156 MPa, the formed part (CS1) obtained in Example 1 has a tensile strength of 206 MPa and a yield strength of 155 MPa, and the formed part (CS3) obtained in Example 3 has a tensile strength of 198 MPa and a yield strength of 156 MPa, which are significantly improved compared to the columnar billet. The optimal comprehensive mechanical properties are achieved at a hot pressing sintering temperature of 300°C.

[0100] The strain stress curve of the formed part prepared in Comparative Example 1 is shown in Figure 6 ,Will Figure 5 The performance of the continuous solid-state recycling molded parts obtained in the embodiment was compared with the traditional solid-state recycling molded parts in comparative example 1. The results showed that the mechanical properties of the molded parts obtained by the continuous solid-state recycling process in the embodiment of the present invention were equivalent to or even exceeded those of the molded parts obtained by the traditional solid-state recycling process. This shows that the continuous solid-state recycling process effectively simplifies the forming process while achieving the strengthening of the molded parts, thereby achieving the strengthening of metal chips.

[0101] Comparative Example 2

[0102] The same as Example 1, except that the heating ring heats the hot pressing sintering device to 200° C. at a heating rate of 40° C. / min, and the resulting formed part is recorded as S1.

[0103] Comparative Example 3

[0104] The same as Example 1, except that the heating ring heats the hot pressing sintering device to 400° C. at a heating rate of 40° C. / min, and the resulting formed part is recorded as S2.

[0105] The strain stress curves of the molded parts (S1, S2) prepared in Comparative Examples 2 and 3 are shown in Figure 7 ,Will Figure 5 A performance comparison of the continuous solid-state recycled parts obtained in Example 2 with those in Comparative Examples 2 and 3 revealed that the strength and elongation of the recycled parts obtained at sintering temperatures of 200°C and 400°C were lower than those at 300°C. This is because the dual-phase magnesium-lithium alloy involves the coordinated deformation of the Mg and Li phases, and neither too low nor too high a temperature is conducive to improving its performance.

[0106] Comparative Example 4

[0107] The same as Example 2, except that the cleaned alloy chips are placed in the extrusion barrel of the hot pressing sintering device, the heating ring heats the hot pressing sintering device to 300°C at a heating rate of 40°C / min, and then the chips are hot-pressed and sintered for 1 minute. The hot pressing sintering process is carried out under a pressure of 200 MPa.

[0108] The strain stress curve results of the formed part prepared in Comparative Example 4 are shown in Figure 8 ,Will Figure 5 The performance of the continuous solid-state recovery molded part obtained in Example 2 was compared with the molded part in Comparative Example 4. The results showed that the strength of the molded part was significantly reduced, and the reduction of the holding time of hot pressing sintering was not conducive to improving the mechanical properties of the molded part.

[0109] The above are merely preferred embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for continuous solid-state recovery of alloy chips, characterized in that: The process includes four steps: blank preparation, chip hot pressing and sintering, hot extrusion, and quenching of the formed part. The three steps of chip hot pressing and sintering, hot extrusion, and heat treatment form a continuous and efficient forming process. The heating temperature of the chip hot pressing and sintering step is 250-350°C, the holding time is 5 minutes, and the pressure is 200 MPa. The continuous solid-state recovery process of alloy chips is carried out in a hot pressing and sintering device, which includes a punch, an extrusion barrel, a pad and a heating ring. The diameter of the punch is the same as the inner diameter of the extrusion barrel, and the punch moves up and down inside the extrusion barrel. The pad is located at the bottom of the extrusion barrel, the inner diameter of the heating ring is the same as the outer diameter of the extrusion barrel, and the heating ring is located outside the extrusion barrel. The pad of the hot pressing and sintering device is a detachable device. After the hot pressing and sintering is completed, the pad is replaced by an extrusion die for hot extrusion. The heat treatment die is connected to the bottom of the extrusion die through a connecting fixture. The heat treatment die is provided with a circulation channel. Specifically, the following steps are included: 1) collecting alloy chips generated during machining, ultrasonically cleaning the alloy chips in alcohol, and then drying them for later use; 2) placing the cleaned alloy chips in the extrusion barrel of the hot pressing and sintering device, and hot pressing and sintering the chips by heating the heating ring; 3) While the chips are hot pressed and sintered, the extrusion die used for the hot extrusion process is placed in a heating furnace for heating; 4) After the hot pressing and sintering of the chips is completed, the backing plate in the hot pressing and sintering device is removed, and the extrusion die heated in step 3) is inserted into the extrusion barrel of the hot pressing and sintering device, and heated and kept warm; 5) The heat treatment die is installed under the extrusion die through the connecting fixture for hot extrusion, and the coolant is introduced through the circulation channel for quenching; 6) The alloy chips are deformed by hot extrusion to form continuous solid-state recycling parts; 7) Take out the continuous solid-state recovery formed parts to achieve continuous solid-state recovery of alloy chips.

2. The method for continuous solid-state recovery of alloy chips according to claim 1, characterized in that: The hot extrusion temperature is 300° C. and the holding time is 3 minutes.

3. The method for continuous solid-state recovery of alloy chips according to claim 1, characterized in that: The extrusion speed of the hot extrusion is 0.1 mm / s.

4. The method for continuous solid-state recovery of alloy chips according to claim 1, characterized in that: In step 3), the extrusion die used for the hot extrusion device is placed in a heating furnace and heated to 300°C.

5. The method for continuous solid-state recovery of alloy chips according to claim 1, characterized in that: In step 2), the heating rate of the heating ring is 40°C / min.

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