Preparation method of high-straightness Ti6Al4V titanium alloy wire for additive manufacturing powder preparation

Abstract

The invention belongs to the field of titanium alloy material production and manufacturing, and discloses a preparation method of a densely-arranged Ti6Al4V titanium alloy wire for high-straightness additive manufacturing powder manufacturing. The method comprises the steps of blank selection, heat treatment, cold drawing, peeling, roller die cold drawing and on-line annealing, polishing, close-packed rewinding and the like, the surface of the titanium alloy wire can be bright in the whole drawing process through multi-pass roller die cold drawing and atmosphere protection on-line annealing, and the defects of pits, scratches, pits and the like on the surface of the wire can be effectively avoided; therefore, the surface quality of the final finished wire is high. According to the method, the weight and the straightness of the single coil of the wire reach corresponding technical standards by perfecting procedure arrangement and improving close-packed rewinding equipment.

Description

Technical Field

[0001] The invention belongs to the field of titanium alloy material production and manufacturing, and in particular relates to a method for preparing a Ti6Al4V titanium alloy wire for high-straightness additive manufacturing and powder making. Background Art

[0002] Titanium alloys have the advantages of low density, high temperature resistance, high yield strength ratio, and strong corrosion resistance. They are widely used in aerospace, ships, weapons, and biomedical fields. Ti6Al4V, as a typical α+β two-phase titanium alloy, is mainly used as a raw material for the preparation of key structural parts in the above fields. The current domestic manufacturing industry has gradually transformed into digitalization and intelligence. The key to the survival of enterprises in society and the core of production technology renewal lies in reducing costs and increasing efficiency. Therefore, additive manufacturing technology based on metal wires has become a hot spot for research and application at home and abroad in recent years due to its many advantages such as free design flexibility, high material utilization, fast production speed, and low environmental pollution. At the same time, as a Ti6Al4V titanium alloy wire for manufacturing metal parts, in the face of the increasingly wide demand and increasingly stringent product standards of the additive manufacturing industry, the original wire for powder making has gradually shown its disadvantages such as small unit weight, low straightness, and poor dimensional consistency. In order to solve this series of problems, the requirements for powder making equipment and raw materials are gradually increasing, which also poses new challenges to the wire production process. Summary of the invention

[0003] In view of this, in view of the technical problems existing in the current Ti6Al4V titanium alloy wire, the purpose of the present invention is to provide a method for preparing a densely packed Ti6Al4V titanium alloy wire for additive manufacturing powder making with high straightness, so as to meet the technical requirements of maintaining high straightness of the titanium alloy wire in a densely packed state.

[0004] In order to achieve the above object, the present invention provides the following technical solutions.

[0005] On the one hand, the present invention provides a method for preparing a densely packed Ti6Al4V titanium alloy wire for powder making in high straightness additive manufacturing, which comprises the following steps:

[0006] (1) Blank selection:

[0007] Select black coils with good surface quality and chemical composition that meets the standards;

[0008] (2) Heat treatment:

[0009] The black coil is annealed, heated to 600℃~800℃, kept warm, and air-cooled after being taken out of the furnace;

[0010] (3) Cold drawing:

[0011] The black coil obtained in step (2) is cold drawn, and the surface reduction rate is controlled to be 10% to 40%;

[0012] (4) Peeling:

[0013] The cold-drawn black coil obtained in step (3) is peeled, and the diameter reduction is 0.2 mm to 1.5 mm;

[0014] (5) Roller die cold drawing and online annealing:

[0015] The peeled black skin coil obtained in step (4) is subjected to multiple roller die cold drawing, and an atmosphere protection online annealing cycle treatment to process the coil to a target size;

[0016] (6) Polishing:

[0017] Polishing the processed coil obtained in step (5);

[0018] (7) Closely packed winding:

[0019] The polished coil obtained in step (6) is densely rewound to obtain a high-straightness Ti6Al4V titanium alloy wire for additive manufacturing powder making.

[0020] Furthermore, in step (1), the size of the black leather coil is Φ8.0 mm.

[0021] Furthermore, in step (2), the black skin coil is placed in a pit annealing furnace for annealing.

[0022] Furthermore, in step (2), the insulation time is 60 minutes.

[0023] Furthermore, in step (4), after the black skin coil is peeled, the surface quality of the coil is inspected and defects are manually polished.

[0024] Furthermore, in step (5), the surface reduction rate of each roller die cold drawing pass is controlled to be 10% to 50%.

[0025] Furthermore, in step (5), the multiple passes are 2 to 5 passes.

[0026] Furthermore, in step (5), the atmosphere protection online annealing cycle treatment adopts 730°C to 760°C through heating.

[0027] Furthermore, in step (6), the polishing depth is 0.02 mm.

[0028] On the other hand, the present invention also provides a high-straightness Ti6Al4V titanium alloy wire for additive manufacturing powder making, which is prepared by the above-mentioned preparation method.

[0029] Compared with the existing production process, the technical solution provided by the present invention has the following beneficial effects:

[0030] (1) Multi-pass roller die cold drawing and atmosphere protection online annealing can achieve a bright surface of titanium alloy wire throughout the drawing process. Compared with vacuum annealing furnace annealing, it can effectively avoid defects such as pits, scratches, and pitting on the wire surface, so the surface quality of the final finished wire is high. Roller die cold drawing can achieve rapid diameter reduction of wire, greatly improving actual production efficiency. The continuous online annealing production line can relieve the internal stress of the wire and improve the straightness of the finished product. At the same time, it can avoid the abnormal growth of grains that may occur when heated under high temperature conditions for a long time, making the grain distribution of the wire more uniform after heat treatment.

[0031] (2) By improving the close-packed rewinding equipment and adopting the process method of active pay-off + close-packed rewinding, the final product can still maintain good straightness after pay-off in a close-packed state. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a product picture of the Ti6Al4V titanium alloy wire prepared in Example 1 of the present invention;

[0033] Figure 2 This is a longitudinal metallographic structure diagram of the Ti6Al4V titanium alloy wire prepared in Example 1 of the present invention;

[0034] Figure 3 This is a transverse metallographic structure diagram of the Ti6Al4V titanium alloy wire prepared in Example 1 of the present invention;

[0035] Figure 4 This is the test result of the surface contamination layer of the Ti6Al4V titanium alloy wire prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the specification of the present invention are only used for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0037] In the present invention, when it comes to numerical intervals (i.e., numerical ranges), unless otherwise specified, the optional numerical distribution is considered continuous within the above numerical interval, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical range, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to the integers within the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints. In this article, it is equivalent to directly listing each integer, such as t is an integer selected from 1-10, indicating that t is any integer selected from the integer group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10. In addition, when multiple ranges are provided to describe features or characteristics, these ranges can be combined. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all sub-ranges included therein.

[0038] The temperature parameters in the present invention, if not specifically limited, are allowed to be either constant temperature treatment or to vary within a certain temperature range. It should be understood that the constant temperature treatment allows the temperature to fluctuate within the precision range controlled by the instrument. Fluctuations within the range of ±5°C, ±4°C, ±3°C, ±2°C, and ±1°C are allowed.

[0039] To clarify the purpose, technical solutions and advantages of the present invention, the present invention will be described in detail below in conjunction with specific embodiments and drawings. The specific embodiments described herein are only used to explain the present invention, and the present invention is not limited thereto.

[0040] Example 1

[0041] This embodiment provides a method for preparing a densely packed Ti6Al4V titanium alloy wire for high straightness additive manufacturing powder making, which comprises the following steps:

[0042] (1) Blank selection:

[0043] Select black coils with good surface quality and chemical composition content in line with the AMS 4930 and ASTM B 863 standards. Inspect the surface condition of the coils to remove defects such as ears and cracks to prevent them from being carried into the next process. The size of the black coils used is Φ8.0mm.

[0044] (2) Heat treatment:

[0045] The black coil is annealed in a pit furnace, heated to 750°C, kept at this temperature for 60 minutes, and then air-cooled after being taken out of the furnace.

[0046] (3) Cold drawing:

[0047] The black coil obtained in step (2) is cold drawn at a drawing rate of 3 to 4 m / min and a surface reduction rate of 10% to 12%.

[0048] (4) Peeling:

[0049] The cold-drawn black coil obtained in step (3) is peeled, and the peeling diameter reduction is 0.4mm-0.6mm. Finally, the surface quality of the coil is inspected and defects are manually polished.

[0050] (5) Roller die cold drawing and online annealing:

[0051] The peeled black coil obtained in step (4) is subjected to 4 passes of roller die cold drawing and online annealing cycle treatment, the surface reduction rate of each drawing pass is 15% to 25%, and the wire size after drawing is Φ4.2 (±0.03) mm.

[0052] Atmosphere protection online annealing, 750℃ through heating.

[0053] (6) Polishing:

[0054] The coil obtained in step (5) is polished with a flap wheel to ensure that the surface of the coil is bright, and the final finished product size is Φ4.2 (±0.05) mm.

[0055] Step (7), close-packed rewinding:

[0056] The polished coil obtained in step (6) is densely rewound, and the coil diameter after rewinding is between 550 mm and 820 mm, and the single coil weight is 160 kg, which is Ti6Al4V titanium alloy wire.

[0057] Example 2

[0058] This embodiment provides a high straightness densely packed Ti6Al4V titanium alloy wire for additive manufacturing powder making, which includes:

[0059] Step (1), blank selection:

[0060] Select black coils with good surface quality and chemical composition content in accordance with AMS 4930 and ASTM B 863 standards, inspect the surface condition of the coils, remove defects such as ears and cracks, and prevent them from being brought into the next process. The size is Φ8.0mm.

[0061] Step (2), heat treatment:

[0062] The black coil is annealed in a pit furnace, heated to 750°C, kept at this temperature for 60 minutes, and then air-cooled after being taken out of the furnace.

[0063] Step (3), cold drawing:

[0064] The black coil obtained in step (2) is cold drawn at a drawing rate of 3 to 4 m / min and a surface reduction rate of 12% to 14%.

[0065] Step (4): Peeling

[0066] The coil obtained in step (3) is peeled, and the diameter reduction amount of the peeling is 0.4mm-0.6mm. Finally, the surface quality of the coil is inspected and defects are manually repaired.

[0067] Step (5), roller die cold drawing + online annealing:

[0068] The peeled black coil obtained in step (4) is subjected to three passes of roller die cold drawing and online annealing cycle treatment, with each drawing pass having a surface reduction rate of 25% to 35%, and the wire size after drawing is Φ3.6 (±0.03) mm.

[0069] Atmosphere protection online annealing, 740℃ through heating.

[0070] Step (6), polishing:

[0071] The coil obtained in step (5) is polished with a flap wheel to ensure that the surface of the coil is bright, and the final finished product size is Φ3.6 (±0.05) mm.

[0072] Step (7), close-packed rewinding:

[0073] The polished coil obtained in step (6) is densely rewound, and the coil diameter after rewinding is between 550 mm and 820 mm, and the weight of a single coil is 160 kg.

[0074] Example 3

[0075] This embodiment provides a high straightness densely packed Ti6Al4V titanium alloy wire for additive manufacturing powder making, which includes:

[0076] Step (1), blank selection:

[0077] Select black coils with good surface quality and chemical composition content in accordance with AMS 4930 and ASTM B 863 standards, inspect the surface condition of the coils, remove defects such as ears and cracks, and prevent them from being brought into the next process. The size is Φ8.0mm.

[0078] Step (2), heat treatment:

[0079] The black coil is annealed in a pit furnace, heated to 750°C, kept at this temperature for 60 minutes, and then air-cooled after being taken out of the furnace.

[0080] Step (3), cold drawing:

[0081] The black coil obtained in step (2) is cold drawn at a drawing rate of 3 to 4 m / min and a surface reduction rate of 14% to 16%.

[0082] Step (4): Peeling

[0083] The coil obtained in step (3) is peeled, and the diameter reduction amount of the peeling is 0.4mm-0.6mm. Finally, the surface quality of the coil is inspected and defects are manually repaired.

[0084] Step (5), roller die cold drawing and online annealing:

[0085] The peeled black coil obtained in step (4) is subjected to two passes of roller die cold drawing and online annealing cycle treatment, the surface reduction rate of each drawing pass is 35% to 45%, and the wire size after drawing is Φ3.0 (±0.03) mm.

[0086] Atmosphere protection online annealing, 730℃ through heating.

[0087] Step (6), polishing:

[0088] The coil obtained in step (5) is polished with a thousand-blade wheel to ensure that the surface of the coil is bright. The final finished product size is Φ3.0 (±0.05) mm

[0089] Step (7), close-packed rewinding:

[0090] The polished coil obtained in step (6) is densely rewound, and the coil diameter after rewinding is between 550 mm and 820 mm, and the weight of a single coil is 160 kg.

[0091] Figure 1 The product picture of the Ti6Al4V titanium alloy wire prepared in Example 1 is shown in FIG. Figure 2 and 3 The longitudinal and transverse metallographic structures of the Ti6Al4V titanium alloy wire prepared in Example 1 are shown in FIG. Figure 2 and 3 It can be seen that the transverse and longitudinal microstructures of the finished titanium alloy wires are both α+β two-phase region processed microstructures, and no other metallurgical defects such as cracks, shrinkage holes, pores, segregation, metal or non-metal inclusions were found. Figure 4 The surface contamination layer test results show that the prepared Ti6Al4V titanium alloy wire has excellent surface quality and the finished product has no surface contamination layer.

[0092] Table 1 shows the curvature test results of the finished Ti6Al4V titanium alloy wires prepared in Examples 1 to 3. As can be seen from Table 1, the wires after unwinding do not show obvious curvature, which indicates that the Ti6Al4V titanium alloy wires prepared in the embodiments of the present invention still maintain a high straightness in the densely packed winding state.

[0093] Table 1

[0094]

[0095] Table 2 shows the H content test results of the finished Ti6Al4V titanium alloy wires prepared in Examples 1 to 3. From the test results in Table 2, it can be seen that the chemical composition of the finished Ti6Al4V titanium alloy wires is stable, and the H content is lower than the standard requirement.

[0096] Table 2

[0097]

[0098]

[0099] In summary, the present invention uses black coils as raw materials, and removes surface defects by annealing, drawing, peeling, and manual spot repair of the intermediate material to ensure that there are no defects remaining on the surface of the semi-finished product. The wire production process that combines continuous annealing + roller die cold drawing ensures high wire straightness and good dimensional accuracy; finally, surface contamination is removed by polishing to ensure the surface quality and roughness of the finished product. By improving the process arrangement and the improvement of the close-packed rewinding equipment, it is ensured that the weight and straightness requirements of a single coil of wire meet the corresponding technical standards.

[0100] The technical solution provided by the present invention has mature production process technology, stable finished product size, excellent wire straightness, and uniform transverse and longitudinal metallographic structure, which can meet the different material requirements of current industrial production. Therefore, this high-straightness Ti6Al4V titanium alloy wire for additive manufacturing powder making has a very broad market application prospect.

[0101] It should be noted that the above-described embodiments are only preferred embodiments of the present invention. For those skilled in the art, without departing from the principles of the present invention, the present invention may be modified, improved and replaced with equivalents, and these modifications, improvements and equivalent replacements are also considered to fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a densely packed Ti6Al4V titanium alloy wire for high straightness additive manufacturing powder making, characterized in that: The steps include: (1) Blank selection: Select black coils with good surface quality and chemical composition that meets the standards; (2) Heat treatment: The black coil is annealed, heated to 600℃~800℃, kept warm, and air-cooled after being taken out of the furnace; (3) Cold drawing: The black coil obtained in step (2) is cold drawn, and the surface reduction rate is controlled to be 10% to 40%; (4) Peeling: The cold-drawn black coil obtained in step (3) is peeled, and the diameter reduction is 0.2 mm to 1.5 mm; (5) Roller die cold drawing and online annealing: The peeled black skin coil obtained in step (4) is subjected to multiple roller die cold drawing, and an atmosphere protection online annealing cycle treatment to process the coil to a target size; (6) Polishing: Polishing the processed coil obtained in step (5); (7) Closely packed winding: The polished coil obtained in step (6) is densely rewound to obtain a high-straightness Ti6Al4V titanium alloy wire for additive manufacturing powder making.

2. The method for preparing Ti6Al4V titanium alloy wire for powder making with high straightness for additive manufacturing according to claim 1, characterized in that: In step (1), the size of the black leather coil is Φ8.0 mm.

3. The method for preparing Ti6Al4V titanium alloy wire for powder making with high straightness for additive manufacturing according to claim 1, characterized in that: In step (2), the black skin coil is placed in a pit annealing furnace for annealing.

4. The method for preparing Ti6Al4V titanium alloy wire for powder making with high straightness for additive manufacturing according to claim 1, characterized in that: In step (2), the insulation time is 60 minutes.

5. The method for preparing Ti6Al4V titanium alloy wire for powder making with high straightness for additive manufacturing according to claim 1, characterized in that: In step (4), after the black skin coil is peeled, the surface quality of the coil is inspected and defects are manually polished.

6. The method for preparing Ti6Al4V titanium alloy wire for powder making in additive manufacturing with high straightness according to claim 1, characterized in that: In step (5), the surface reduction rate of each roller die cold drawing pass is controlled to be 10% to 50%.

7. The method for preparing Ti6Al4V titanium alloy wire for powder making in additive manufacturing with high straightness according to claim 1, characterized in that: In step (5), the plurality of passes is 2 to 5 passes.

8. The method for preparing Ti6Al4V titanium alloy wire for powder making with high straightness for additive manufacturing according to claim 1, characterized in that: In step (5), the atmosphere protection online annealing cycle treatment adopts 730°C to 760°C through heating.

9. The method for preparing Ti6Al4V titanium alloy wire for powder making in additive manufacturing with high straightness according to claim 1, characterized in that: In step (6), the polishing depth is 0.02 mm.

10. A Ti6Al4V titanium alloy wire for powder making with high straightness, characterized in that: The method is prepared according to any one of claims 1 to 9.

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