CN111842530B

CN111842530B - High-performance wire production process method and device

Info

Publication number: CN111842530B
Application number: CN202010640924.3A
Authority: CN
Inventors: 陈志浩; 刘超; 曹伟; 朱协彬; 姚敏
Original assignee: Anhui Polytechnic University
Current assignee: Anhui Polytechnic University
Priority date: 2020-07-06
Filing date: 2020-07-06
Publication date: 2022-04-26
Anticipated expiration: 2040-07-06
Also published as: CN111842530A

Abstract

The invention discloses a high-performance wire rod production process method and a device, belonging to the technical field of severe plastic deformation fine grains, wherein the process method comprises the steps of material selection and cleaning, ultrasonic impact strengthening treatment preparation, ultrasonic impact strengthening treatment, two-piece welding, multi-pass rolling treatment and the like to obtain a finished product with unchanged section size, and a finished product with uniformly thinned section size can be obtained after one-time ultrasonic impact strengthening treatment; the low-temperature ultrasonic rolling impact device comprises a closed container filled with cooling liquid, an ultrasonic transducer, an ultrasonic tool head, a rigid impact roller, an ultrasonic power supply, a rigid roller, a roller driving motor, a pressure cylinder, a spring and a traction transmission mechanism. The process method provided by the invention can realize the efficient refinement of uniform crystal grains of the wire or the strip with the thickness of micron-sized dimension, and obviously improve the comprehensive mechanical property of the material; the device provided can realize the low-temperature ultrasonic impact SPD strengthening treatment of the wire or the strip, and can meet two impact treatment modes.

Description

High-performance wire production process method and device

Technical Field

The invention relates to the technical field of Severe Plastic Deformation (SPD) fine grains, in particular to a high-performance wire production process method and a high-performance wire production device for an ultra-fine metal wire or an ultra-thin strip.

Background

The severe Plastic Deformation method (SPD) has great potential of refining the crystal grains of the coarse-grained material to nanometer level, and is a unique superfine (nano-crystalline or sub-micro-crystalline) metal and alloy material preparation process which is gradually developed in recent years. It means that the material is at a lower temperature (typically less than 0.4T)_m) In the environment, the severe plastic deformation is generated under the action of large external pressure, thereby the grain size of the material is thinned to submicron or nanometer levelA process of (1). The microstructure of the metal material can be obviously refined under the condition of low temperature due to the large plastic deformation of the strong strain, so that the strength and the toughness of the metal material are greatly improved.

To date, ultrasonic vibration has been widely used and studied in the field of assisted metal forming due to its unique characteristics of interface friction reduction, acoustic softening, and reduction of surface roughness. On a macroscopic scale, the traditional high-power ultrasonic vibration is widely applied to the improvement of manufacturing processes such as surface treatment and metal forming. For example, ultrasonic rolling is a newly developed technique that combines the advantages of conventional rolling and ultrasonic techniques. In contrast to conventional rolling techniques, ultrasonic rolling relies primarily on high frequency ultrasonic vibration rather than pressure to treat the sample surface. At present, the ultrasonic rolling technology is mainly applied to the surface treatment of block macroscopic materials, and a surface gradient nano structure can be obtained.

On a microscopic scale, the application of ultrasonic vibration as an auxiliary means in micro-forming processes of stretching, compressing, surface finishing and the like of a micro-metal piece becomes a research focus in the field. However, little work has been done to investigate the potential of ultrasonic vibration in the field of reinforcement of the SPD, which is a micro-metallic part directly related to flow forming. The research objects of various SPD methods developed at present mainly aim at macroscopic materials, and the ultrasonic vibration technology can only play an auxiliary role in the method. This is because the ultrasonic vibration amplitude is small, and generally only a gradient micro/nano structure can be formed in a range of tens of micrometers, so that the influence range of the SPD is very limited.

The metal wire and the foil are used as engineering materials with wide application, have the unique characteristic that the dimension in a certain dimension direction is far smaller than that in other dimensions, and therefore the structure of the metal wire and the foil is between that of a bulk material and that of a micro material. Obviously, with the reduction of the thickness of the wire and the foil, the ultrasonic vibration acting on the thickness direction of the wire and the foil is expected to bring high-efficiency and comprehensive SPD introduction to the whole wire and foil, but no high-performance wire production process method and device aiming at the ultra-fine metal wire or the ultra-thin strip exist at present.

Disclosure of Invention

1. Technical problem to be solved

The technical problem to be solved by the invention is to provide a high-performance wire rod production process method and a high-performance wire rod production device, the provided process method can realize the high-efficiency refinement of crystal grains in the thickness direction of a wire rod or a strip with the thickness of micron grade, the size and the shape distribution of the crystal grains are uniform, and the comprehensive mechanical property of the wire rod or the strip is obviously improved; the device provided can continuously and efficiently introduce severe plastic deformation, realize continuous low-temperature ultrasonic impact SPD strengthening treatment of wires or strips, can meet two impact treatment modes, and has high application value.

2. Technical scheme

In order to solve the problems, the invention adopts the following technical scheme:

a production process method of a high-performance wire rod comprises the following steps:

s1, selecting materials and cleaning: reasonably selecting a micro-sized wire rod, and cleaning the surface to remove dirt;

s2, ultrasonic impact strengthening treatment preparation: preparing an ultrasonic rolling processing device for carrying out ultrasonic impact strengthening processing on the wire rod, and reasonably determining the passing speed, the ultrasonic frequency and the ultrasonic amplitude of the wire rod;

s3, ultrasonic impact strengthening treatment: starting an ultrasonic rolling processing device, enabling the wire rod cleaned in the step S1 to pass through the ultrasonic rolling processing device at a constant speed, and carrying out ultrasonic impact strengthening processing on the wire rod by the ultrasonic rolling processing device to obtain a processed wire rod I with constant width and reduced thickness;

s4, welding: overlapping the processing wire rods I with the reduced thicknesses obtained in the two steps S3, and welding the processing wire rods I through an ultrasonic welding device to obtain a processing wire rod II with the thickness recovered to the initial thickness;

s5, multi-pass rolling treatment: repeating the step S3-S4 on the processing wire II obtained in the step S4, wherein the repetition times are determined according to requirements;

s6, obtaining a finished product: and (5) winding the wire rod finally obtained in the step (S5) to obtain a finished wire rod II with the section size not changed obviously.

Further, the wire is directly coiled after being processed in the steps S1-S3, so that the flat wire subjected to single-pass ultrasonic impact strengthening treatment or the finished strip I with the uniformly-thinned section can be effectively obtained.

Further, in steps S2 and S3, the ultrasonic impact reinforcement treatment is divided into two ways, one is that a static pressure is constantly applied to the rolling end portion in the ultrasonic rolling treatment device, and the other is that the rolling end portion in the ultrasonic rolling treatment device defines the passing height of the wire rod, specifically:

A. a treatment mode of constantly loading static pressure on the rolling end part in the ultrasonic rolling treatment device is adopted, and in the step S2, the constant static pressure of the static pressure generation system in the ultrasonic rolling treatment device is reasonably determined;

B. in step S2, the height of the rolled end in the ultrasonic rolling processing device for the wire to pass through is the sum of half the thickness of the wire and the ultrasonic amplitude.

Specifically, in step S4, the ultrasonic welding device is an ultrasonic metal seam welder.

Further, in step S5, when the treated wire rod ii obtained exhibits a severe work hardening phenomenon, the treated wire rod ii is subjected to high-temperature short-time softening annealing to alleviate the hardening phenomenon. Taking a copper wire as an example, the temperature of high-temperature short-time annealing of the wire rod is 300-600 ℃, and the passing time is 4-30 s.

Specifically, in step S1, the diameter and thickness of the micro-sized wire are both within 1 mm; in step S2, the ultrasonic amplitude value is 1-100 μm; the ultrasonic frequency value is 15-50 kHz.

The invention also provides a low-temperature ultrasonic rolling impact device adopted by the high-performance wire rod production process method, which comprises a closed liquid cooling temperature control mechanism, a traction transmission mechanism and an ultrasonic rolling impact mechanism;

the closed liquid cooling temperature control mechanism comprises a closed container filled with cooling liquid, the outer shell of the closed container is of a double-layer structure, and the inner layer is a heat insulation layer made of heat insulation materials; an input port and an output port for a wire to pass through are correspondingly formed in two opposite sides of the sealed container in the length direction respectively, the liquid level of the cooling liquid is lower than that of the input port and the output port, an injection port for introducing the cooling liquid and an outflow port for discharging the cooling liquid are further formed in the side wall of the sealed container, and switch valves are arranged at the injection port and the outflow port; a plurality of pressure rods which vertically extend downwards are fixed at the top in the closed container, and limiting holes for the wires to pass through are formed in the pressure rods;

the traction transmission mechanism comprises a plurality of groups of transmission rollers which are respectively positioned outside an input port and an output port of the closed container, each group of transmission rollers comprises two rollers with opposite rotation directions, the belt material passes through the transmission rollers of each group, and at least one group of transmission rollers is connected with a driving motor;

the ultrasonic rolling impact mechanism comprises an ultrasonic system, a static pressure generation system and an impact base arranged in the closed container;

the ultrasonic system comprises an ultrasonic transducer vertically arranged at the top of the closed container, an ultrasonic horn arranged at the lower end of the ultrasonic transducer and penetrating through a top panel of the closed container, an ultrasonic tool head vertically connected to the lower end of the ultrasonic transducer, a rigid impact roller column which is rotatably embedded on the lower end face of the ultrasonic tool head and provided with a groove body structure (a groove or a convex groove), and an ultrasonic power supply which is electrically connected with the ultrasonic transducer and arranged outside the closed container, wherein the top of the closed container is provided with an access port for the ultrasonic horn to penetrate through, the ultrasonic tool head and the rigid impact roller column are both positioned in the closed container, the rigid impact roller column is parallel to the width direction of the closed container, and the groove body structure on the rigid impact roller column surrounds the closed container by one circle;

the static pressure generating system comprises a pressure plate detachably arranged on the top surface of the ultrasonic transducer and a pressure cylinder arranged above the pressure plate, a spring is connected between the pressure cylinder and the pressure plate, and the upper end of the pressure cylinder is a fixed end of the pressure cylinder;

the impact base comprises a rigid roller with a groove structure or a convex groove structure on the surface immersed in cooling liquid, and a roller driving motor arranged on the outer side of the closed container and used for driving the rigid roller, the length of the rigid roller is parallel to the width direction of the closed container, the groove structure on the rigid roller surrounds the rigid roller by a circle, the groove structure on the surface of the rigid roller is positioned under the groove structure on the surface of the rigid impact roller column, the groove structure on the surface of the rigid roller is in concave-convex fit with the groove structure on the surface of the rigid impact roller column, the widths of the two groove structures are the same as the width of a wire, and an ultrasonic rolling processing channel of the wire is formed between the two groove structures (the channel combination of the groove on the surface of the rigid impact roller column and the convex groove on the surface of the rigid roller, or the channel combination of the convex groove on the surface of the rigid impact roller and the groove on the surface of the rigid roller), the wire rod penetrates through the ultrasonic rolling processing channel, and the hardness and the elastic modulus of the rigid impact roller column and the rigid roller are both larger than those of the wire rod; the rotating direction of the roller wheel positioned below the wire is the same as that of the rigid roller; and both sides of the rigid roller in the length direction are provided with pressure bars.

Further, the lengths of the pressing rods on the two sides of the rigid roller are different. The lower end of the pressure lever between the rigid roller and the input port of the wire rod is lower than the top of the rigid roller, so that after the wire rod enters the closed container, the wire segment before ultrasonic treatment is kept to be wholly immersed in cooling liquid, the temperature of the wire segment is guaranteed to be cooled to the treatment temperature, and the ultrasonic impact strengthening treatment of the wire rod is facilitated; the lower end of the pressure bar between the rigid roller and the wire outlet is not lower than the top of the rigid roller, and is preferably flush with the rigid roller, so that the wire can be conveniently discharged.

Specifically, the cooling liquid is liquid nitrogen or water. For wires made of different materials, different rolling impact strengthening treatment temperatures can be selected, preferably liquid nitrogen cooling temperature can be selected, and the temperature can be controlled at room temperature in a water cooling mode.

Furthermore, the pressing plate is horizontally arranged and fixedly installed on the ultrasonic transducer, guide rods which are vertically arranged and penetrate through the pressing plate are fixed on the top surface of the closed container and located on two sides of the ultrasonic transducer, through holes for the corresponding side guide rods to penetrate through are formed in two end sides of the pressing plate, and locking screws penetrating through the through holes to the corresponding side are arranged on the two end sides of the pressing plate. The pressing plate can be locked on the guide rod through the locking screw, so that the ultrasonic transducer, the ultrasonic tool head and the rigid impact roller can be driven to realize position fixation, the passing height of a wire between the rigid impact roller and the rigid roller can be limited, and the requirement of a processing mode that the passing height is limited at the rolling end in the ultrasonic rolling processing device is met; the locking screw is unscrewed, the pressing plate can be allowed to drive the ultrasonic transducer to move up and down under the driving of the pressure cylinder, the acting pressure of the rolling end part on the wire can be controlled through the pressure cylinder, namely the pressure of the rigid impact roller column acting on the wire, and the requirement of a processing mode of adopting the constant loading static pressure of the rolling end part in the ultrasonic rolling processing device can be met. The ultrasonic transducer and the pressing plate are not required to be separated and assembled, and the ultrasonic transducer is not required to be fixed after being separated from the pressing plate, so that the ultrasonic transducer is convenient to use.

3. Advantageous effects

(1) The invention designs a high-performance wire production process method, which applies high-frequency high-strain-rate ultrasonic vibration impact to micron-level foils or wires by utilizing the action of ultrasonic plastic waves, so that severe plastic deformation is efficiently and uniformly generated in ultra-fine wires or ultra-thin strips, and crystal grains are obviously refined; experimental research and simulation show that the process can realize the efficient refinement of the crystal grains in the thickness direction of the micron-sized wire or strip, the size and the shape of the crystal grains are uniformly distributed, and the comprehensive mechanical property of the wire or strip can be obviously improved.

(2) The invention designs a series of treatment process flows of a high-performance wire production process method, has simple operation, realizes the high-efficiency severe plastic deformation introduction of metal or metal-based wires and strips through repeated ultrasonic vibration impact under different temperature conditions, and finally forms the ultrafine crystal material with obviously refined grains to submicron and nanometer scales and uniform size distribution. On the premise of not changing the section size obviously, the severe plastic deformation can be introduced into the wire rod with the micrometer-level thickness continuously and uniformly in multiple passes in a high-efficiency mode, the material performance can be greatly improved, and the method has practical engineering application value.

(3) The invention relates to a low-temperature ultrasonic rolling impact device, which comprises a closed container filled with cooling liquid, wherein the opposite sides of the closed container are respectively provided with an input port and an output port for wires or strips to pass through, and the outer side of the closed container is provided with a plurality of groups of transmission roller sets, so that the wires or the strips can continuously pass through the closed container and are subjected to impact treatment in the closed container. Because the recrystallization refinement and the grain recovery synchronously occur inside the material in the severe plastic deformation process, the two aspects are balanced under the comprehensive action, and the minimum grain size which can be achieved by the material under the process condition is determined, the temperature factor is reduced, the inhibition on the grain recovery can be obviously achieved, the smaller minimum grain size is obtained, and the grain refinement effect is improved.

(4) The low-temperature ultrasonic rolling impact device comprises a static pressure generating system, wherein the static pressure generating system comprises a pressure plate detachably arranged on the top surface of an ultrasonic transducer and a pressure cylinder arranged above the pressure plate, a spring is connected between the pressure cylinder and the pressure plate, and the upper end of the pressure cylinder is a fixed end of the pressure cylinder. The pressing plate and the ultrasonic transducer are separated, and the ultrasonic transducer is fixed, so that the ultrasonic tool head and the rigid impact roller can be driven to realize position fixation, and the requirement of a processing mode of limiting the passing height of the rolling end part in the ultrasonic rolling processing device is met; the pressing plate is arranged on the energy converter, the ultrasonic energy converter can be driven by the pressing plate to move up and down under the driving of the pressure cylinder, the pressure of the rolling end part on a wire or a strip can be controlled through the pressure cylinder, the requirement of a processing mode of adopting the constant loading static pressure of the rolling end part in the ultrasonic rolling processing device can be met, the device can meet two impact processing modes, and the application value is high.

In conclusion, the process method provided by the invention can realize the efficient refinement of the crystal grains in the thickness direction of the micron-level wire or strip, the size and the shape of the crystal grains are uniformly distributed, and the comprehensive mechanical properties of the wire or strip are obviously improved; the device provided can continuously and efficiently introduce severe plastic deformation, realize continuous low-temperature ultrasonic impact SPD strengthening treatment of wires or strips, can meet two impact treatment modes, and has high application value.

Drawings

FIG. 1 is a schematic view of a low-temperature ultrasonic rolling impact device for high-performance wires provided by the invention;

FIG. 2 is a schematic view of an end portion of an ultrasonic tool head 12 fitted with a rigid impact roller 11;

FIG. 3 is a schematic view of the wire or strip 6 passing between the tongue of the rigid impact roller 11 and the groove of the rigid roller 8;

FIG. 4 is a schematic view of the ultrasonic tool head 12 driving the rigid roller 11 to vibrate and impact in a high frequency in a longitudinal direction and roll the passing wire or strip 6 together with the rigid roller 8;

FIG. 5 is a schematic diagram of the PEEQ trapezoidal structure distribution generated on a 3 mm T2 copper wire cross section under ultrasonic rolling pressure simulated by ABAQUS;

FIG. 6 is a schematic diagram of the uniform structural distribution of PEEQ produced on a 200 μm cross section of T2 copper wire under ultrasonic rolling pressure simulated by ABAQUS;

FIG. 7 is a graph of the maximum PEEQ values produced under ultrasonic impact at the same conditions for copper plates of different thicknesses, reduced from 3 mm to 50 μm;

FIG. 8 is a schematic process flow diagram of a high-performance wire rod production process provided by the present invention;

FIG. 9 is a schematic view of a treated cross section of a T2 copper wire with a thickness of 100 μm and a width of 5mm, wherein (a) is an EBSD (electron back scattering) texture map of the treated cross section of the T2 pure copper wire with a thickness of 100 μm in example 1, wherein (b) is a grain size distribution map thereof, and wherein (c) is a grain boundary orientation angle distribution map thereof;

FIG. 10 is a schematic view of a cross section of a T2 copper wire rod with a thickness of 100 μm and a width of 5mm after single-pass ultrasonic rolling treatment, wherein (a) is a photograph of a cross-sectional structure of a T2 pure copper wire rod with a thickness of 100 μm in example 1 after single-pass ultrasonic rolling treatment; FIG. (B) is the EBSD structure morphology map of the B region in FIG. (a), FIGS. (c), (d) and (e) are the TEM structure maps of three different local regions, c, (d) and e, respectively, in FIG. (B), FIG. (f) is the grain size distribution map, and FIG. (g) is the grain boundary orientation angle distribution map;

FIG. 11 is an EBSD microstructure of a cross-section of a 304 stainless steel wire rod of 300 μm diameter in both width and thickness in example 2 before treatment;

FIG. 12 is a structural diagram of EBSD (Electron Back scattered) cross-section of a 304 stainless steel wire rod with 300 μm diameter in both width and thickness in example 2, which is subjected to liquid nitrogen deep cooling and multi-pass continuous ultrasonic rolling treatment.

Reference numerals: 1. an ultrasonic power supply; 2. pressing a plate; 3. an ultrasonic transducer; 4. a closed container; 5. a pressure lever; 6. a wire or strip; 7. cooling liquid; 8. a rigid roll; 9. a roller driving motor; 10. a conveying roller; 11. a rigid impact roller; 12. an ultrasonic tool head; 13. a pressure cylinder; 14. a spring; 15. a guide rod.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

Under the ultrasonic rolling pressure simulated by ABAQUS, 3 mm T2 copper wires and 200 μm T2 copper wires are respectively subjected to ultrasonic impact strengthening treatment, and the change situation of effective plastic strain (PEEQ) in the thickness direction along with the gradual reduction of the material thickness from a macroscopic dimension to a micrometer-level dimension is studied when the ultrasonic vibration impact direction acts on the thickness direction of the wire rod. As shown in fig. 5 and 6, when the ultrasonic vibration impact direction is applied to the thickness direction of the wire rod, the distribution of the effective plastic strain (PEEQ) in the thickness direction is changed from a gradient distribution structure to a uniform distribution structure as the thickness of the material is gradually reduced from the macro size to the micrometer level size, as can be seen from fig. 5 and 6.

Under the ultrasonic impact under the same condition, the ultrasonic impact strengthening treatment is carried out on copper plates with different thicknesses, the change of the maximum PEEQ value generated on materials with different thicknesses is researched, and as seen from figure 7, and as the thickness of the material is gradually reduced from a macroscopic size to a micrometer level size, the maximum PEEQ value generated under the ultrasonic impact under the same condition is exponentially increased according to figure 7.

From the above, in the field of micro-forming, when the size of the material is reduced to the influence range of ultrasonic vibration, the small ultrasonic amplitude is no longer a disadvantage, but the high frequency/high rate strain characteristic is not possessed by other SPD processes.

Example 1

The T2 strip with the thickness of 100 mu m and the width of 5mm is subjected to single-pass liquid cooling temperature-controlled ultrasonic rolling continuous impact thinning treatment, and the chemical components of the T2 rolled pure copper foil are shown in Table 1:

TABLE 1 TABLES FOR CHEMICAL COMPONENTS (%) > OF T2 ROLLED PURE COPPER FOIL

Cu

Bi

Sb

Pb

As

S

O

≥99.90

≤0.002

≤0.005

≤0.002

≤0.005

≤0.006

The low-temperature ultrasonic rolling impact device is adopted as shown in figure 1, figure 2, figure 3 and figure 4,

the device comprises a closed liquid cooling temperature control mechanism, a traction transmission mechanism and an ultrasonic rolling impact mechanism;

the closed liquid cooling temperature control mechanism comprises a closed container 4 filled with cooling liquid 7, the outer shell of the closed container 4 is of a double-layer structure, and the inner layer is a heat insulation layer made of heat insulation materials; an input port and an output port through which a wire or a strip 6 passes are correspondingly formed in two opposite sides of the sealed container 4 in the length direction respectively, the liquid level of the cooling liquid 7 is lower than the input port and the output port, an injection port for introducing the cooling liquid and an outflow port for discharging the cooling liquid are further formed in the side wall of the sealed container 4, and switch valves are arranged at the injection port and the outflow port; a plurality of pressure levers 5 which vertically extend downwards are fixed at the top in the closed container 4, and limiting holes for wires or strips 6 to pass through are formed in the pressure levers 5;

the traction transmission mechanism comprises a plurality of groups of transmission rollers 10 which are respectively positioned outside an input port and an output port of the closed container 4, each group of transmission rollers 10 comprises two rollers with opposite rotation directions, the wires or the strips 6 pass through the transmission rollers 10, and at least one group of transmission rollers 10 is connected with a driving motor;

the ultrasonic rolling impact mechanism comprises an ultrasonic system, a static pressure generation system and an impact base arranged in the closed container 4;

the ultrasonic system comprises an ultrasonic transducer 3 vertically arranged at the top of a closed container 4, an ultrasonic horn arranged at the lower end of the ultrasonic transducer 3 and penetrating through a top panel of the closed container 4, an ultrasonic tool head 12 vertically connected to the lower end of the ultrasonic transducer 3, a rigid impact roller 11 with a groove body structure (which can be a groove or a convex groove, in the embodiment, the convex groove) rotatably embedded on the lower end surface of the ultrasonic tool head 12, and an ultrasonic power supply 1 electrically connected with the ultrasonic transducer 3 and arranged outside the closed container 4, wherein the top of the closed container 4 is provided with an access port for the ultrasonic horn to pass through, the ultrasonic tool head 12 and the rigid impact roller 11 are both positioned inside the closed container 4, the rigid impact roller 11 is parallel to the width direction of the closed container 4, and the groove body structure on the rigid impact roller 11 surrounds the closed container by one circle;

the static pressure generating system comprises a pressure plate 2 which is detachably arranged on the top surface of the ultrasonic transducer 3 and a pressure cylinder 13 which is arranged above the pressure plate 2, a spring 14 is connected between the pressure cylinder 13 and the pressure plate 2, and the upper end of the pressure cylinder 13 is a fixed end thereof;

the impact base comprises a rigid roller 8 with a groove body structure (a groove or a convex groove in the embodiment) on the surface immersed in cooling liquid 7, and a roller driving motor 9 arranged on the outer side of the closed container 4 and used for driving the rigid roller 8, wherein the length of the rigid roller 8 is parallel to the width direction of the closed container 4, the groove body structure on the rigid roller 8 surrounds the rigid roller for one circle, the groove body structure on the surface of the rigid roller 8 is positioned under the groove body structure on the surface of the rigid impact roller column 11, the groove body structure on the surface of the rigid roller 8 is in concave-convex fit with the groove body structure on the surface of the rigid impact roller column 11, the widths of the two groove body structures are the same as the width of a wire or strip 6, an ultrasonic rolling processing channel of the wire or strip 6 is formed between the two groove body structures, and the wire or strip 6 passes through the ultrasonic rolling processing channel, the rigidity impact roller 11 and the rigidity roller 8 have hardness and elastic modulus larger than those of the wire or strip 6; the rotating direction of the roller wheel positioned below the wire or strip 6 is the same as that of the rigid roller 8; and two sides of the rigid roller 8 in the length direction are provided with pressure levers 5.

In this embodiment, the length of the struts 5 on both sides of the rigid roller 8 is different. The lower end of the compression bar 5 between the rigid roller 8 and the input port of the wire or strip 6 is lower than the top of the rigid roller 8, so that after the wire or strip 6 enters the closed container 4, the wire section before ultrasonic treatment is kept wholly immersed in cooling liquid, and the temperature of the wire section is guaranteed to be cooled to the treatment temperature, thereby being beneficial to ultrasonic impact strengthening treatment of the wire or strip 6; the lower end of the strut 5 between the rigid roller 8 and the outlet of the wire or strip 6 is not lower than the top of the rigid roller 8, preferably flush with the aforementioned outlet, to facilitate the discharge of the wire or strip 6.

In this embodiment, the cooling liquid 7 is liquid nitrogen or water. For wires or strips made of different materials, different rolling impact strengthening treatment temperatures can be selected, preferably liquid nitrogen cooling temperature can be selected, and the temperature can be controlled at room temperature in a water cooling mode.

In this embodiment, the pressing plate 2 is horizontally disposed and fixedly mounted on the ultrasonic transducer 3, the two sides of the top surface of the closed container 4, which are located on the ultrasonic transducer 3, are fixed with the guide rods 15 which are vertically disposed and penetrate through the pressing plate 2, through holes for the corresponding side guide rods 15 to penetrate through are formed in the two end sides of the pressing plate 2, and the two end sides of the pressing plate 2 are provided with the locking screws penetrating through to the corresponding side through holes. The pressing plate 2 can be locked on the guide rod 15 through a locking screw, so that the ultrasonic transducer 3, the ultrasonic tool head 12 and the rigid impact roller 11 can be driven to realize position fixation, the passing height of the wire or the strip 6 between the rigid impact roller 11 and the rigid roller 8 can be limited, and the requirement of a processing mode that the passing height of a rolling end in an ultrasonic rolling processing device is limited is met; the locking screw is unscrewed, the pressing plate 2 can be allowed to drive the ultrasonic transducer 3 to move up and down under the driving of the pressure cylinder 13, the pressure of the rolling end part on the wire or the strip can be controlled through the pressure cylinder 13, (namely, the pressure of the rigid impact roller 11 acting on the wire or the strip), and the requirement of a processing mode of constantly loading static pressure on the rolling end part in the ultrasonic rolling processing device can be met. The ultrasonic transducer 3 and the pressing plate 2 are not required to be separated and assembled, the ultrasonic transducer 3 is not required to be fixed after the ultrasonic transducer 3 is separated from the pressing plate 2, and the application is convenient.

The ultrasonic transducer 3 converts the electric oscillation into 28 kHz ultrasonic wave, the ultrasonic amplitude transformer further amplifies the amplitude, and drives a superhard tungsten carbide cobalt (WC/Co) rigid roller 11 (with the diameter of 8mm and the width of 10mm, the width of a surface convex groove of 5mm and the height of 2mm, the surface roughness (Ra) of 0.1 mu m and the hardness of 80 HRC) at the top of the ultrasonic tool head 12 to generate longitudinal high-frequency vibration; measuring the vibration amplitude by using a laser displacement sensor, wherein the amplitude of the end part is 10 mu m; the static load is applied by the spring 14, measured by the load cell as 200N; the rigid roller 8 is made of high-carbon steel, and the width and the depth of a surface groove are 5mm and 1.8mm respectively. The uniform unidirectional passing speed of the T2 strip is 10 mm/s; the liquid cooling mode is water cooling; the process comprises the following steps:

s1, selecting materials and cleaning: selecting a micro-size T2 strip material, wherein the thickness of the material is 100 mu m, and the width of the material is 5mm, and cleaning the surface of the material to remove dirt;

s2, ultrasonic impact strengthening treatment preparation: in the ultrasonic rolling processing device, the locking screw is unscrewed, the pressure plate 2 is allowed to drive the ultrasonic transducer 3 to move up and down under the driving of the pressure cylinder 13, the constant loaded static pressure at the rolling end part is controlled to be 200N through the pressure cylinder 13, the passing speed of the T2 strip is 10 mm/s, the ultrasonic frequency is 28 kHz, and the ultrasonic amplitude is 15 mu m;

s3, ultrasonic impact strengthening treatment: starting the ultrasonic transducer 3, starting a driving motor of the transmission roller 10, enabling the cleaned T2 strip in the step S1 to pass through the ultrasonic rolling impact mechanism at a constant speed through a plurality of groups of transmission rollers 10, and carrying out ultrasonic impact strengthening treatment on the T2T2 strip by using an ultrasonic rolling treatment device;

s4, obtaining a finished product: and (4) rolling the strip subjected to the ultrasonic impact strengthening treatment in the step S3 to obtain a finished wire I with the cross section size being uniformly reduced to 60 mu m on average after the ultrasonic impact strengthening.

As shown in FIG. 9, wherein (a) is the EBSD structure morphology chart of the treated cross section of the T2 copper strip with the diameter of 200 μm, (b) is the grain size distribution chart thereof, and (c) is the grain boundary orientation angle distribution chart thereof, the average grain size of the treated cross section of the T2 copper strip with the diameter of 200 μm is 2.5 μm; the low angle grain boundaries (less than 5 °) were 27%. After the water-cooling single-pass continuous ultrasonic rolling treatment, as shown in fig. 10, wherein, fig. (a) is a photograph of a cross-section structure of a T2 pure copper strip with a diameter of 200 μm after the single-pass ultrasonic rolling treatment, fig. (B) is an EBSD structure morphology diagram of a B area in fig (a), fig. (c), fig (d) and fig (e) are TEM structure diagrams of three different local areas c, d and e in fig (B), respectively, fig (f) is a grain size distribution diagram, fig (g) is a grain boundary orientation angle distribution diagram, and the EBSD diagram and the TEM diagram of the different areas all show that significantly refined nano-grains are uniformly distributed at all positions of the cross-section without generating a gradient structure; the grain size distribution diagram shows that the average grain size of the cross section of the T2 pure copper strip with the diameter of 200 mu m is reduced to 0.51 mu m after the single-pass ultrasonic rolling treatment; the grain boundary orientation angle distribution indicates a 17.5% reduction in low angle grain boundaries (less than 5 °). Therefore, under the action of severe plastic strain, the small-angle grain boundary is changed into a large-angle grain boundary, which shows that a fine grain process mainly based on a continuous dynamic recrystallization mechanism is generated inside the material.

In addition, the mechanical tensile test shows that the yield strength of the wire rod is increased from 79MPa before treatment to 152MPa after the treatment of the steps.

Example 2

The 304 austenitic stainless steel wire rod with the width and the thickness of 300 mu m is subjected to multi-pass liquid cooling temperature control ultrasonic rolling continuous impact treatment, and the adopted low-temperature ultrasonic rolling impact device is the same as that in the embodiment 1.

The ultrasonic transducer 3 converts the electric oscillation into 20 kHz ultrasonic wave, the ultrasonic amplitude transformer further amplifies the amplitude, and drives a GCr15 bearing steel rigid impact roller 11 (with the diameter of 6 mm and the width of 10 mm; the width of a surface groove of 300 mu m and the depth of 1 mm; the surface roughness (Ra) of 0.1 mu m and the hardness of 64 HRC) at the top of the ultrasonic tool head 12 to generate longitudinal high-frequency vibration; measuring the vibration amplitude by using a laser displacement sensor, wherein the amplitude of the end part is 30 mu m; fixing the ultrasonic amplitude transformer to enable the distance between the impact rigid roller 11 and the rigid roller 8 to be the sum of the ultrasonic amplitude and half of the thickness of the wire rod, namely 30+150=180 (mum); the rigid roller 8 driven by the motor is made of high-carbon steel, and the width of a convex groove on the surface is 300 mu m and the height is 2 mm; the uniform unidirectional passing speed of the 304 stainless steel wire is 15 mm/s; the liquid cooling mode is liquid nitrogen cooling; as shown in fig. 8, the process is as follows:

s1, selecting materials and cleaning: selecting 304 austenitic stainless steel wires, wherein the width and the thickness of the material are both 300 mu m, and cleaning the surface of the material to remove dirt;

s2, ultrasonic impact strengthening treatment preparation: in the ultrasonic rolling processing device, the pressing plate 2 is locked on the guide rod 15 through a locking screw, the ultrasonic transducer 3, the ultrasonic tool head 12 and the rigid impact roller 11 can be driven to realize position fixation, and the distance between the rigid impact roller 11 and the rigid roller 8 is limited to be 180 mu m; the passing speed of the 304 austenitic stainless steel wire rod is 15 mm/s, the ultrasonic frequency is 20 kHz, and the ultrasonic amplitude is 10 mu m;

s3, ultrasonic impact strengthening treatment: starting an ultrasonic rolling processing device, starting a driving motor of a transmission roller 10, enabling the 304 austenitic stainless steel wire cleaned in the step S1 to pass through the ultrasonic rolling impact mechanism at a constant speed through a plurality of groups of transmission rollers 10, and carrying out ultrasonic impact strengthening processing on the 304 austenitic stainless steel wire by the ultrasonic rolling processing device to obtain a processing wire I with the section thickness of 158 micrometers and the width of 300 micrometers;

s4, welding: overlapping the two processing wires I obtained in the step S3, and welding the two processing wires I by an ultrasonic welding device to obtain a processing wire II with the thickness recovered to the initial thickness (about 300 mu m);

s5, softening and annealing treatment: if the treated wire II has serious work hardening phenomenon, performing high-temperature short-time softening annealing (such as bright annealing of a stainless steel wire at 950 ℃ for 15 s in a protective atmosphere, and then quickly cooling to below 500 ℃) to obtain a treated wire II with plastic recovery;

s6, multi-pass rolling treatment: repeating the steps S3 to S5 for 2 times on the processed wire III obtained in the step S5;

s7, obtaining a finished product: and (5) winding the wire rod finally obtained in the step (S6) to obtain a finished wire rod II with the section size not changed obviously.

As shown in FIG. 11, the EBSD structure of a cross section of a 304 stainless steel wire rod having a width and a thickness of 300 μm before treatment showed an austenite grain structure having an average grain size of 7.3. mu.m. The EBSD of the cross-sectional structure after the liquid nitrogen cooling multi-pass continuous ultrasonic rolling treatment is shown in FIG. 12, and the average grain size is reduced to 0.61 μm. The EBSD plot shows that the significantly refined nanocrystals are uniformly distributed throughout the cross-section.

The mechanical tensile test shows that the yield strength of the steel is increased from 201MPa to 370MPa before treatment.

According to the content, the process method provided by the invention can realize the efficient refinement of the crystal grains in the thickness direction of the micron-level wire or strip, the size and the shape distribution of the crystal grains are uniform, and the comprehensive mechanical properties of the wire or strip are obviously improved; the device provided can continuously and efficiently introduce severe plastic deformation, realize continuous low-temperature ultrasonic impact SPD strengthening treatment of wires or strips, can meet two impact treatment modes, and has high application value.

It should be understood by those skilled in the art that the above embodiments are only for illustrating the present invention and are not to be used as a limitation of the present invention, and that changes and modifications to the above embodiments are within the scope of the claims of the present invention as long as they are within the spirit and scope of the present invention.

Claims

1. A production process method of a high-performance wire rod is characterized by comprising the following steps:

s6, obtaining a finished product: winding the wire rod finally obtained in the step S5 to obtain a finished wire rod II with the section size not changed obviously;

the ultrasonic rolling processing device is a low-temperature ultrasonic rolling impact device and comprises a closed liquid cooling temperature control mechanism, a traction transmission mechanism and an ultrasonic rolling impact mechanism;

the closed liquid cooling temperature control mechanism comprises a closed container (4) filled with cooling liquid (7), the outer shell of the closed container (4) is of a double-layer structure, and the inner layer is a heat insulation layer made of heat insulation materials; an input port and an output port through which a wire (6) passes are correspondingly formed in two opposite sides of the sealed container (4) in the length direction respectively, the liquid level of the cooling liquid (7) is lower than the input port and the output port, an injection port for introducing the cooling liquid and an outlet port for discharging the cooling liquid are further formed in the side wall of the sealed container (4), and switch valves are arranged at the injection port and the outlet port; a plurality of pressure rods (5) which vertically extend downwards are fixed at the top in the closed container (4), and limiting holes for wires (6) to pass through are formed in the pressure rods (5);

the traction transmission mechanism comprises a plurality of groups of transmission rollers (10) which are respectively positioned on the outer side of an input port and the outer side of an output port of the closed container (4), each group of transmission rollers (10) comprises two rollers with opposite rotation directions, the wires (6) pass through the transmission rollers (10) of each group, and at least one group of transmission rollers (10) is connected with a driving motor;

the ultrasonic rolling impact mechanism comprises an ultrasonic system, a static pressure generation system and an impact base arranged in the closed container (4);

the ultrasonic system comprises an ultrasonic transducer (3) vertically arranged at the top of the closed container (4), an ultrasonic amplitude transformer arranged at the lower end of the ultrasonic transducer (3) and penetrating through the top panel of the closed container (4), an ultrasonic tool head (12) vertically connected to the lower end of the ultrasonic transducer (3), a rigid impact roller column (11) with a groove body structure which can be rotatably embedded on the lower end surface of the ultrasonic tool head (12), and an ultrasonic power supply (1) which is electrically connected with the ultrasonic transducer (3) and is arranged outside the closed container (4), the top of the closed container (4) is provided with an access port for the ultrasonic amplitude transformer to pass through, the ultrasonic tool head (12) and the rigid impact roller (11) are both positioned in the closed container (4), the rigid impact roller (11) is parallel to the width direction of the closed container (4), and a groove body structure on the rigid impact roller (11) surrounds the closed container by one circle;

the static pressure generating system comprises a pressure plate (2) detachably arranged on the top surface of the ultrasonic transducer (3) and a pressure cylinder (13) arranged above the pressure plate (2), a spring (14) is connected between the pressure cylinder (13) and the pressure plate (2), and the upper end of the pressure cylinder (13) is a fixed end thereof;

the impact base comprises a rigid roller (8) with a groove structure on the surface immersed in cooling liquid (7) and a roller driving motor (9) which is arranged on the outer side of a closed container (4) and used for driving the rigid roller (8), the length of the rigid roller (8) is parallel to the width direction of the closed container (4), the groove structure on the rigid roller (8) surrounds a circle, the groove structure on the surface of the rigid roller (8) is positioned under the groove structure on the surface of a rigid impact roller column (11), the groove structure on the surface of the rigid roller (8) is in concave-convex fit with the groove structure on the surface of the rigid impact roller column (11), the widths of the two groove structures are the same as the width of a wire (6), an ultrasonic rolling processing channel of the wire (6) is formed between the two groove structures, and the wire (6) passes through the ultrasonic rolling processing channel, the hardness and the elastic modulus of the rigid impact roller (11) and the rigid roller (8) are both greater than those of the wire (6); the rotating direction of the roller wheel positioned below the wire (6) is the same as that of the rigid roller (8); and both sides of the rigid roller (8) in the length direction are provided with pressure levers (5).

2. The production process of high-performance wire rods according to claim 1, wherein the wire rods are directly coiled after being processed in steps S1-S3, and a flat wire rod or a finished strip material I with uniformly reduced section size is obtained after being processed by single-pass ultrasonic impact strengthening.

3. The high-performance wire rod production process method according to claim 1 or 2, wherein in steps S2 and S3, the ultrasonic impact reinforcement treatment is divided into two ways, one is constant static pressure loading to the rolling end in the ultrasonic rolling treatment device, and the other is that the rolling end in the ultrasonic rolling treatment device defines the passing height of the wire rod, specifically:

a treatment mode of constantly loading static pressure on the rolling end part in the ultrasonic rolling treatment device is adopted, and in the step S2, the constant static pressure of the static pressure generation system in the ultrasonic rolling treatment device is reasonably determined;

in step S2, the height of the rolled end in the ultrasonic rolling processing device, through which the wire passes, is the sum of half the thickness of the wire and the ultrasonic amplitude.

4. The process of claim 3, wherein in step S4, the ultrasonic welding device is an ultrasonic metal seam welder.

5. The process for producing a high-performance wire rod as claimed in claim 4, wherein in step S5, when the treated wire rod II is severely work hardened, the treated wire rod II is subjected to high-temperature short-time softening annealing.

6. The production process method of the high-performance wire rod according to claim 5, wherein in the step S1, the diameter and the thickness of the micro-size wire rod are both within 1 mm; in step S2, the ultrasonic amplitude value is 1-100 μm; the ultrasonic frequency value is 15-50 kHz.

7. The production process of high-performance wire rod as claimed in claim 1, wherein the length of the compression bar (5) at two sides of the rigid roller (8) of the low-temperature ultrasonic rolling impact device is different.

8. The production process of high-performance wire rod according to claim 7, wherein the cooling liquid (7) of the low-temperature ultrasonic rolling impact device is liquid nitrogen or water.

9. The production process method of the high-performance wire rod according to claim 1, wherein the pressing plate (2) of the low-temperature ultrasonic rolling impact device is horizontally arranged and fixedly installed on the ultrasonic transducer (3), guide rods (15) which are vertically arranged and penetrate through the pressing plate (2) are fixed on the top surface of the closed container (4) and located on two sides of the ultrasonic transducer (3), through holes for the corresponding side guide rods (15) to penetrate through are formed in two end sides of the pressing plate (2), and locking screws penetrating through the corresponding side through holes are formed in two end sides of the pressing plate (2).