CN118305417A - Separating spiral powder feeding friction stir welding and additive manufacturing device and method with adjustable powder feeding rate - Google Patents

Abstract

The invention discloses a device and a method for separating type spiral powder feeding friction stir welding and additive manufacturing with an adjustable powder feeding rate, which relate to the technical fields of solid phase additive and friction stir welding, wherein a separating type rotating head and a spiral rotary powder feeding part are arranged in a stirring head rotating body; the separated rotating head can move up and down under the drive of the power source so as to drive the spiral rotary powder feeding part to rotate or separate from the spiral rotary powder feeding part; the spiral powder transferring part conveys powder to the lower end surface of the stirring head revolving body in the rotating process; and the stirring head revolving body rotates to stir, rub and increase materials for the workpiece. The powder feeding process is carried out in a closed way in the whole process, powder splashing can be prevented, the powder feeding speed can be adjusted in real time according to manufacturing and processing requirements, the powder feeding process is more flexible and controllable, the stirring friction welding is carried out by the rotation of the stirring head revolving body, the use scene of the device is enriched, and the economic benefit is improved.

Description

Separating spiral powder feeding friction stir welding and additive manufacturing device and method with adjustable powder feeding rate

Technical Field

The invention relates to the technical fields of solid phase material adding and friction stir welding, in particular to a separated spiral powder feeding friction stir welding device with an adjustable powder feeding rate and a material adding manufacturing device and method.

Background

Friction stir welding is to utilize heat generated by friction between a stirring head rotating at a high speed and a workpiece to locally melt a welded material, and when a welding tool moves forwards along a welding interface, the plasticized material flows from the front part to the rear part of the welding tool under the action of rotating friction force of the welding tool, and a compact solid-phase welding seam is formed under the extrusion of the stirring head.

The friction stir additive manufacturing is used as a solid phase non-melting additive manufacturing method, is derived from a friction stir welding technology, and can realize the high-strength and high-toughness design of the superfine crystal compact structure and the uniform dispersion and distribution of the second phase of the additive due to the strong dynamic recovery, recrystallization and second phase crushing redistribution characteristics caused by the large plastic deformation and deformation self-heating behaviors of the friction stir welding technology, and is particularly suitable for manufacturing aluminum, aluminum alloy, magnesium alloy, light metal composite materials and the like. The principle is as follows: the material generates heat by friction under the action of a cutter rotating at a high speed, and simultaneously, the material on the advancing side returns to the returning side by the high-speed rotation of a stirring needle, so that the material is softened by heat generated by friction and plastic deformation, a molten core solidification structure is formed under the longitudinal pressure of the cutter, the cutter moves according to a preset track under the control of a control system to form a pure core component formed by a molten core structure, and finally, additive manufacturing is realized, namely, the stirring friction welding principle is utilized to assist in feeding, and stirring friction additive is realized. Friction stir welding and friction stir additive functions may thus be integrated on one device.

Friction stir additive may be divided into axial additive, radial additive, consumable friction stir tool additive and stacked plate mode additive. The axial material adding can be divided into wires, powder, bars, particles and an material adding device capable of adding various material adding materials according to the adopted material adding materials, wherein powder is often used as the material adding material for friction stir material adding, chinese patent publication No. CN115178855A proposes a friction stir material manufacturing processing head, a system and a material adding manufacturing method for coaxial powder feeding, the powder is fed into a space of a concave part through a through annular powder feeding channel from top to bottom, the powder is subjected to friction stirring processing forming when being rotated by a stirring needle, the smooth powder conveying is ensured, meanwhile, the splashing of the powder when the powder is discharged is prevented, the powder convergence is good, the utilization rate is high, however, in the whole material adding process, the powder feeding rate is completely dependent on the geometric characteristics of the channel, and the powder feeding rate is difficult to adapt to a friction stir scene needing to be regulated.

Disclosure of Invention

Aiming at the defects existing in the prior art, the invention provides a separated spiral powder feeding friction stir welding and additive manufacturing device with adjustable powder feeding rate and a method thereof; when the upper clutch teeth of the separated transmission head are separated from the lower clutch teeth of the spiral rotary powder feeding part, the device is used for friction stir welding, no powder is input, and the device performs friction stir welding through the rotation of the stirring head rotary body.

The present invention achieves the above technical object by the following means.

A separated spiral powder feeding friction stir welding and additive manufacturing device with adjustable powder feeding rate comprises a separated rotating head, a stirring head rotating body and a spiral rotary powder feeding part;

The separated rotating head and the spiral rotary powder feeding part are arranged in the stirring head rotary body;

The separated rotating head can move up and down under the drive of the power source so as to drive the spiral rotary powder feeding part to rotate or separate from the spiral rotary powder feeding part;

The spiral rotary powder feeding part is used for conveying powder to the lower end face of the stirring head rotary body in the rotating process; and the stirring head revolving body rotates to stir, rub and increase materials for the workpiece.

In the scheme, the stirring head revolving body comprises a feeding channel, a revolving body internal cavity, a discharging port and a conical stirring head; the feeding channel is communicated with the inner cavity of the revolving body, an inverted cone-shaped storage cavity is formed below the inner cavity of the revolving body, and the inverted cone-shaped storage cavity is communicated with the discharge port; the conical stirring head is arranged below the cavity in the revolving body, and the outer side of the conical stirring head surrounds a plurality of discharge holes.

In the scheme, the discharge port comprises a notch and a ring port; the radial size of the notch is smaller than that of the annular opening; the upper end face of the notch is coplanar with the lower end face of the conical storage cavity.

In the above scheme, the feeding channel comprises a vertical section and an inclined section; the vertical section is parallel to the axis of the stirring head revolving body, and the inclined section has a certain included angle with the axis of the stirring head revolving body; the inclined section is communicated with the cavity inside the revolving body; and the outlet position of the inclined section is slightly higher than the upper end of the spiral powder conveying channel in the spiral rotary powder conveying part.

In the scheme, the radial dimension of the inverted cone-shaped storage cavity is larger than that of the spiral powder conveying channel in the spiral rotary powder conveying part.

In the above scheme, the separated transmission head comprises a transmission rod, an upper clutch tooth is arranged on the transmission rod, and the transmission rod rotates downwards to drive the upper clutch tooth to be meshed with a lower clutch tooth of the spiral rotary powder feeding part.

In the above scheme, the transmission rod is further provided with a first positioning shaft shoulder for positioning the needle bearing or the transmission rod is supported by the sliding shaft sleeve.

In the scheme, the spiral rotary powder feeding part comprises a lower clutch tooth, a spiral powder feeding channel and a shaft section; the lower clutch teeth are provided with a spiral powder feeding channel below, the lower end part of the spiral powder feeding channel is provided with a second lower end surface, and a shaft end is arranged below the second lower end surface and extends into a conical stirring head in the stirring head revolving body.

In the scheme, a second positioning shaft shoulder is arranged between the shaft end and the second lower end surface; the second positioning shaft shoulder is used for positioning a bearing arranged on the shaft end.

The method of the separated spiral powder feeding friction stir welding and additive manufacturing device with adjustable powder feeding rate comprises two modes of additive manufacturing or/and friction stir welding,

Additive manufacturing includes the steps of:

Starting a stirring head revolving body, wherein a conical stirring head on the stirring head revolving body is firstly pricked into an additive manufacturing substrate in a high-speed rotating state until the first lower end surface of the stirring head revolving body is contacted with the upper surface of the additive manufacturing substrate, and preheating and maintaining for a period of time;

The separated transmission head is driven by an external linear motor and an axial rotating motor, is combined with a lower clutch tooth in a state of rotating at a given speed to drive the spiral powder feeding channel and the separated transmission head to synchronously rotate, then material powder is input through a feeding channel in a stirring head rotating body, the powder enters a cavity in the rotating body along the feeding channel and then enters the spiral powder feeding channel, the powder is conveyed downwards in the spiral powder feeding channel in the spiral line direction under the action of self gravity and the rotation of a spiral powder feeding part until the powder flows out from the second lower end surface of the spiral powder feeding channel, so that the powder enters a storage cavity in the rotating body, and the rotation speed of the spiral powder feeding channel can be regulated by regulating the rotation speed of the separated transmission head during the process, so that the powder conveying efficiency can be regulated;

After powder enters the storage cavity, the powder flows to a discharge hole of the stirring head revolving body under the action of self gravity and a slope diversion structure below the storage cavity, at the moment, the lower end surface of the stirring head revolving body is in contact with the upper surface of the additive manufacturing substrate, the powder is accumulated in a ring opening of the discharge hole and is plastically deformed under the friction stirring action of the conical stirring head, and the stirring friction is carried out on the powder in the ring opening and a molten pool by combining the high-speed rotation of the stirring head revolving body and the conical stirring head, so that the metal powder is plastically deformed and continues to be plastically deformed; finally, under the actions of extrusion of a stirring head revolving body, stirring friction of a conical stirring head and axial upsetting force, the plastically deformed metal powder is melted in a ring opening and deposited and molded to form a deposition layer;

the friction stir additive welding specifically comprises the following steps:

The linear motor at the separated transmission head controls the linear motor to move upwards along the axis of the revolving body of the stirring head, so that the upper clutch teeth are separated from the lower clutch teeth of the spiral revolving powder feeding part, no powder is input at the feeding channel, and the axial rotating motor at the separated transmission head stops running;

starting a stirring head revolving body, wherein a conical stirring head on the stirring head revolving body is firstly pricked into a preset welding spot in a high-speed rotating state until the conical stirring head is completely pricked into the welding spot, and preheating is kept for a period of time;

the stirring head revolving body moves along a preset route to drive the conical stirring head to carry out friction stir welding.

Compared with the prior art, the invention has the beneficial effects that: the invention improves the friction stir head, a separable spiral powder feeding mechanism is added in the friction stir head, when the upper clutch teeth of the separable transmission head are connected with the lower clutch teeth of the spiral rotary powder feeding part, the device is used for friction stir material increase manufacturing, powder feeding is performed in a whole process in a sealing way, powder splashing can be prevented, and the powder feeding rate can be adjusted in real time according to manufacturing and processing requirements, so that the powder feeding process is more flexible and controllable, and the powder feeding efficiency and the forming effect are improved; when the upper clutch teeth of the separated transmission head are separated from the lower clutch teeth of the spiral rotary powder feeding part, the device is used for friction stir welding, powder is not input, the device performs friction stir welding through the rotation of the stirring head rotary body, the use scene of the device is enriched, and the economic benefit is improved.

Drawings

FIG. 1 is a schematic perspective view of a split spiral powder feeding friction stir welding and additive manufacturing device with an adjustable powder feeding rate;

FIG. 2 is a schematic cross-sectional view of FIG. 1;

FIG. 3 is a schematic cross-sectional view of the stirring head rotor of FIG. 1;

FIG. 4 is a schematic cross-sectional view of the split rotary head and spiral rotary powder feeder of FIG. 1;

FIG. 5 is a schematic view of the discharge port of FIG. 3;

FIG. 6 is a schematic front view of FIG. 5;

fig. 7 is a schematic diagram of a friction stir welding, additive manufacturing method implemented based on the inventive apparatus.

The reference numerals are as follows:

10-split drive head; 11-a transmission rod; 12-a first positioning shoulder; 13-upper clutch teeth;

20-connecting part of the bearing and the bearing end cover; 21-a bearing end cap; 22-screws; 23-needle bearings; 24-angular contact ball bearings;

30-stirring head revolving body; 31-a threaded hole; 32-feeding channels; 33-a hollow cavity inside the revolution body; 34-a discharge hole; 35-a conical stirring head; 301-a first lower end face; 33A-upper bearing positioning shoulder; 33B-lower bearing positioning shoulder; 34A-notch; 34B-ring opening;

40-spiral rotary powder feeding part; 41-lower clutch teeth; 42-spiral powder feeding channel; 43-a second positioning shoulder; 44-shaft section.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.

In the description of the present invention, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "axial," "radial," "vertical," "horizontal," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present invention and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

Referring to fig. 1-7, a continuous feeding, stirring and friction-increasing manufacturing device comprises a separated transmission head 10, a connecting part 20 of a bearing and a bearing end cover, a stirring head rotary body 30 and a spiral rotary powder feeding part 40, wherein clutch teeth 13 on the lower end of the separated transmission head 10 can be combined with lower clutch teeth 41 on the upper end of the spiral rotary powder feeding part 40 to realize cooperative rotation, and the separated transmission head 10 and the spiral rotary powder feeding part 40 are arranged in a rotary body internal cavity 33 of the stirring head rotary body 30.

Referring to fig. 1 and 2, the split type transmission head 10 includes a transmission rod 11, a positioning shaft shoulder 12 and an upper clutch tooth 13, where the transmission rod 11 is connected with an external motor and can transmit radial rotation motion and axial linear motion, the positioning shaft shoulder 12 is disposed between the transmission rod and the upper clutch tooth 13 and is used to cooperate with a bearing end cover 21 to bear and form a needle bearing, the upper clutch tooth 13 is of a fourth-order rotationally symmetrical structure and cooperates with a lower clutch tooth 41 at the upper end of the spiral rotary powder feeding portion 40, so that power of the split type transmission head 10 is transmitted to the spiral powder feeding channel 42, and then the powder feeding rate is controlled by controlling the rotation speed of the spiral channel.

Referring to fig. 1 and 2, the bearing-bearing end cover connection portion 20 includes a bearing end cover 21, four screws 22, a needle bearing 23, and an angular ball bearing 7204C24, where the connection mode between the bearing end cover 21 and the stirring head rotator is screw connection, the screws 22 are M6×20 hexagon socket head screws, the screws are used to connect the bearing end cover 21 and the stirring head rotator, the needle bearing 23 has an upper end on an outer ring thereof constrained by the bearing end cover 21, a lower end thereof constrained by an upper bearing positioning shoulder 33A provided on the stirring head rotator 30, a bearing inner ring is cooperatively connected with a transmission rod 11 of the split transmission head 10, the bearing inner ring of the angular ball bearing 24 is cooperatively connected with a shaft section 44, an upper end thereof constrained by a positioning shoulder 43, and a lower end thereof constrained by a lower bearing positioning shoulder 33B.

As shown in fig. 1,2, 3,5 and 6, the stirring head rotator 30 includes four threaded holes 31, two feeding channels 32, a rotator internal cavity 33, a discharge port 34 and a conical stirring head 35, the two feeding channels 32 and the four threaded holes 31 are arranged on the upper end surface of the stirring head rotator 30, the feeding channels 32 are used for receiving material powder and transmitting the powder downwards, the threaded holes 31 are used for being matched with the screws 22 so as to fix a bearing end cover, the discharge port 34 and the conical stirring head 35 are arranged on the lower end surface of the stirring head rotator 30, the conical stirring head 35 is made of wear-resistant materials, and the cone angle is 15 degrees relative to the axis. In the friction stir welding and material adding process, the stirring head revolving body 30 is driven to rotate by an external motor, and the conical stirring head 35 arranged on the stirring head revolving body synchronously rotates to rub with a workpiece and generate heat so as to locally melt the welded material. An upper bearing positioning shaft shoulder 33A and a lower bearing positioning shaft shoulder 33B are arranged in the internal cavity 33 of the revolving body, a storage cavity 33C is arranged in a partial cavity outside the lower bearing positioning shaft shoulder 33B, the discharge port 34 comprises a notch 34A and a ring port 34B, and the notch 34A is formed by 3 circular arc notches distributed along a circumferential array.

As shown in connection with fig. 1,2 and 4, the screw rotary powder feeding portion 40 includes a lower clutch tooth 41, a screw powder feeding passage 42, a second positioning shoulder 43 and a shaft section 44, and the screw powder feeding passage 42 extends spirally in the axial direction of the screw rotary powder feeding portion 40 for feeding material powder. The second positioning shaft shoulder 43 is arranged at the lower end of the spiral powder feeding channel 42, the diameter of the second positioning shaft shoulder is smaller than the inner diameter of the spiral powder feeding channel, the shaft section 44 is arranged at the lower end of the second positioning shaft shoulder 43, and part of the shaft end extends into the inner space formed by the lower bearing positioning shaft shoulder 33B and is used for being matched with the angular contact ball bearing 24.

The diameter of the first positioning shaft shoulder 12 is between the outer diameters of the transmission rod 11 and the upper clutch teeth 13, the tooth-shaped edges and corners of the upper clutch teeth 13 and the lower clutch teeth 41 are respectively provided with a round angle, the radius of the round angle is 1.5-6mm, and the outer diameters of the upper clutch teeth and the lower clutch teeth are slightly smaller than the inner diameter of the upper bearing positioning shaft shoulder 33A.

The bearing end cover 21 is a flange type bearing end cover and is a bearing through cover, the nominal outer diameter of the flange is slightly smaller than the diameter of a rotary body inner cavity 33 at the upper end face of the stirring head rotary body 30, the nominal width of the flange is 4-16 mm, a tapered inner cavity is arranged in the flange, and the inner diameter d of the through cover is consistent with the diameter of the transmission rod 11.

The feeding channel 32 has two sections, the first section is vertically arranged along the axial direction of the device revolving body, the second section is obliquely arranged, the inclination angle is 35 degrees relative to the axial direction of the device, the channel outlet is led to the cavity 33 inside the revolving body, the outlet position height is higher than the height of the spiral powder feeding channel 42, the diameter of the cavity of the storage cavity 33C close to the powder feeding channel is larger than the outer diameter of the spiral powder feeding channel 42, and the cavity of the storage cavity close to the discharging hole 34 is inwards inclined so as to facilitate powder dumping, and the inclination angle is 18 degrees relative to the axial direction of the device.

The spiral powder feeding channel 42 has a constant spiral thread pitch, the total height is 48-192mm, the number of turns is 2, the cross section of the channel is rectangular, the rectangular length, namely the transverse width of the channel, is 1.5-6mm, the width, namely the longitudinal length of the channel, is 3-12mm, the channel consists of four spiral threads and the cross section, the initial angles of the spiral threads are 0 DEG, 90 DEG, 180 DEG and 270 DEG respectively, the diameter of the positioning shaft shoulder 43 is 0.6 times that of the spiral powder feeding channel 42, and the part of the shaft section 44 extending into the inner space formed by the lower bearing positioning shaft shoulder 33B is 0.4 times that of the total length.

Referring to fig. 1-7, a method for manufacturing a separated spiral powder feeding friction stir welding and additive with an adjustable powder feeding rate is provided, and the device is used for manufacturing the friction stir additive and specifically comprises the following steps:

(1) Starting the stirring head revolving body 30, firstly, penetrating a conical stirring head 35 on the stirring head revolving body 30 into the additive manufacturing substrate in a high-speed rotating state until the lower end face 301 of the stirring head revolving body 30 contacts with the upper surface of the additive manufacturing substrate, and preheating and maintaining for a period of time;

(2) The separated transmission head 10 is driven by an external linear motor and an axial rotating motor, is combined with a lower clutch gear 41 in a state of rotating at a given speed, drives a spiral powder feeding channel 42 to synchronously rotate with the separated transmission head 10, then inputs material powder through a feeding channel 32 in a stirring head revolving body 30, the powder enters a revolving body internal cavity 33 along the feeding channel 32, then enters the spiral powder feeding channel 42, the powder is conveyed downwards in the spiral direction of the spiral powder feeding channel 42 under the action of self gravity and the rotation of a spiral rotary powder feeding part 40 in the spiral powder feeding channel 42 until flowing out from a lower end face 401 of the spiral powder feeding channel 42, and enters a material storage cavity 33C in the revolving body internal cavity 33, and the rotation speed of the spiral powder feeding channel 42 can be regulated by regulating the rotation speed of the separated transmission head 10, so that the powder conveying efficiency can be regulated;

(3) After powder enters the storage cavity 33C, the powder flows to the discharge hole 34 of the stirring head revolving body 30 under the action of the gravity of the powder and the slope diversion structure below the storage cavity 33C, at this time, the lower end face 301 of the stirring head revolving body 30 is in contact with the upper surface of the additive manufacturing substrate, the powder is accumulated in the annular hole 34B of the discharge hole 34 and is subjected to plastic deformation under the friction stirring action of the conical stirring head 35, and the stirring friction is carried out on the powder in the annular hole 34B and the molten pool by combining the high-speed rotation of the stirring head revolving body 30 and the conical stirring head 35, so that the metal powder is subjected to plastic deformation and continues to the plastic deformation. Finally, the plastically deformed metal powder is melted and deposited in the annular opening 34B by the extrusion of the stirring-head rotor 30, the friction stir of the conical stirring head 35, and the axial upsetting force, to form a deposit.

When the device is used for friction stir additive welding, the device specifically comprises the following steps:

(1) The linear motor at the separated transmission head 10 controls the linear motor to move upwards along the axis of the stirring head revolving body 30 to separate the upper clutch teeth 13 from the lower clutch teeth 41 of the spiral revolving powder feeding part 40, at the moment, no powder is input at the feeding channel 32, and the axial rotating motor at the separated transmission head 10 stops running;

(2) Starting the stirring head revolving body 30, firstly, penetrating a conical stirring head 35 on the stirring head revolving body 30 into a preset welding spot in a high-speed rotating state until the conical stirring head 35 is completely penetrated into the welding spot, and preheating and maintaining for a period of time;

(3) The stirring head rotator 30 moves along a preset route to drive the conical stirring head 35 to stir friction welding.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives, and variations may be made in the above embodiments by those skilled in the art without departing from the spirit and principles of the invention.

Claims (10)

1. The separating type spiral powder feeding friction stir welding and additive manufacturing device with the adjustable powder feeding rate is characterized by comprising a separating type rotating head (10), a stirring head rotating body (30) and a spiral rotating powder feeding part (40);

the separating rotary head (10) and the spiral rotary powder feeding part (40) are arranged in the stirring head rotary body (30);

the separated rotating head (10) can move up and down under the drive of a power source so as to drive the spiral rotary powder conveying part (40) to rotate or separate from the spiral rotary powder conveying part (40);

the spiral rotary powder feeding part (40) is used for conveying powder to the lower end face (301) of the stirring head rotary body (30) in the rotating process; the stirring head revolving body (30) rotates to stir friction additive manufacturing on a workpiece.

2. The separated spiral powder feeding friction stir welding and additive manufacturing device with the adjustable powder feeding rate according to claim 1, wherein the stirring head revolving body (30) comprises a feeding channel (32), a revolving body internal cavity (33), a discharging port (34) and a conical stirring head (35); the feeding channel (32) is communicated with the inner cavity (33) of the revolving body, an inverted cone-shaped storage cavity (33C) is formed below the inner cavity (33) of the revolving body, and the inverted cone-shaped storage cavity (33C) is communicated with the discharge hole (34); the conical stirring head (35) is arranged below the cavity (33) in the revolving body, and the outer side of the conical stirring head (35) surrounds a plurality of discharge holes (34).

3. The separate spiral powder feeding friction stir welding and additive manufacturing device with adjustable powder feeding rate according to claim 2, wherein the discharge port (34) comprises a notch (34A) and a ring port (34B); the radial dimension of the notch (34A) is smaller than that of the annular opening (34B); the upper end face of the notch (34A) is coplanar with the lower end face of the conical storage cavity (33C).

4. The separate spiral powder feed friction stir welding, additive manufacturing apparatus of adjustable powder feed rate of claim 2 wherein said feed channel (32) comprises a vertical section and an inclined section; the vertical section is parallel to the axis of the stirring head revolving body (30), and the inclined section has a certain included angle with the axis of the stirring head revolving body (30); the inclined section is communicated with the internal cavity (33) of the revolving body; and the outlet position of the inclined section is slightly higher than the upper end of the spiral powder feeding channel (42) in the spiral rotary powder feeding part (40).

5. The separate type spiral powder feeding friction stir welding and additive manufacturing device with adjustable powder feeding rate according to claim 2, wherein the radial dimension of the inverted cone-shaped storage cavity (33C) is larger than the radial dimension of the spiral powder feeding channel (42) in the spiral rotary powder feeding part (40).

6. The split type spiral powder feeding friction stir welding and additive manufacturing device with adjustable powder feeding rate according to claim 1, wherein the split type transmission head (10) comprises a transmission rod (11), an upper clutch tooth (13) is arranged on the transmission rod (11), and the transmission rod (11) rotates downwards so as to drive the upper clutch tooth (13) to be meshed with a lower clutch tooth (41) of the spiral rotary powder feeding part (40).

7. The separated spiral powder feeding friction stir welding and additive manufacturing device with the adjustable powder feeding rate according to claim 6, wherein a first positioning shaft shoulder (12) is further arranged on the transmission rod (11) and is used for positioning a needle bearing or supporting the transmission rod (11) through a sliding shaft sleeve.

8. The separate type spiral powder feeding friction stir welding and additive manufacturing device with the adjustable powder feeding rate according to claim 1, wherein the spiral rotary powder feeding part (40) comprises a lower clutch tooth (41), a spiral powder feeding channel (42) and a shaft section (44); the lower clutch teeth (41) are provided with a spiral powder feeding channel (42) below, the lower end part of the spiral powder feeding channel (42) is provided with a second lower end surface (401), a shaft end (44) is arranged below the second lower end surface (401), and the shaft end (44) extends into a conical stirring head (35) in the stirring head revolving body (30).

9. The separate spiral powder feeding friction stir welding and additive manufacturing device with adjustable powder feeding rate according to claim 8, wherein a second positioning shaft shoulder (43) is arranged between the shaft end (44) and the second lower end surface (401); the second positioning shoulder (43) is used for positioning a bearing mounted on the shaft end (44).

10. The method of the separated spiral powder feeding friction stir welding and additive manufacturing device with the adjustable powder feeding rate according to any one of claims 1 to 9, which is characterized by comprising two modes of additive manufacturing or/and friction stir welding,

Additive manufacturing includes the steps of:

(1) Starting a stirring head revolving body (30), firstly, penetrating a conical stirring head (35) on the stirring head revolving body (30) into an additive manufacturing substrate in a high-speed rotating state until a first lower end surface (301) of the stirring head revolving body (30) is contacted with the upper surface of the additive manufacturing substrate, and preheating and maintaining for a period of time;

(2) The separated transmission head (10) is driven by an external linear motor and an axial rotating motor, is combined with a lower clutch tooth (41) under the state of rotating at a given speed, drives a spiral powder feeding channel (42) to synchronously rotate with the separated transmission head (10), then inputs material powder through a feeding channel (32) in a revolving body (30) of the stirring head, the powder enters a cavity (33) in the revolving body along the feeding channel (32) and then enters the spiral powder feeding channel (42), the powder is conveyed downwards in the spiral line direction of the spiral powder feeding channel (42) until flowing out from a second lower end face (401) of the spiral powder feeding channel (42) to enter a storage cavity (33C) in the cavity (33) in the revolving body, and the rotation speed of the spiral powder feeding channel (42) can be adjusted by adjusting the rotation speed of the separated transmission head (10), so that the powder conveying efficiency can be adjusted;

(3) After powder enters the storage cavity (33C), flowing to a discharge hole (34) of the stirring head revolving body (30) under the action of self gravity and a slope diversion structure below the storage cavity (33C), wherein the lower end face (301) of the stirring head revolving body (30) is in contact with the upper surface of the additive manufacturing substrate, the powder is accumulated in a ring opening (34B) of the discharge hole (34) and is subjected to plastic deformation under the friction stirring action of the conical stirring head (35), and the stirring friction between the powder in the ring opening (34B) and a molten pool is combined by the high-speed rotation of the stirring head revolving body (30) and the conical stirring head (35), so that the metal powder is subjected to plastic deformation and continues the plastic deformation; finally, under the actions of extrusion of the stirring head revolving body (30), stirring friction of the conical stirring head (35) and axial upsetting force, the plastically deformed metal powder is melted in the annular opening (34B) and deposited and molded to form a deposition layer;

the friction stir additive welding specifically comprises the following steps:

(1) The linear motor at the separated transmission head (10) controls the linear motor to move upwards along the axis of the stirring head revolving body (30) so as to separate the upper clutch teeth (13) from the lower clutch teeth (41) of the spiral revolving powder feeding part (40), at the moment, no powder is input at the feeding channel (32), and the axial rotating motor at the separated transmission head (10) stops running;

(2) Starting a stirring head revolving body (30), firstly, penetrating a conical stirring head (35) on the stirring head revolving body (30) into a preset welding spot in a high-speed rotating state until the conical stirring head (35) is completely penetrated into the welding spot, and preheating and maintaining for a period of time;

(3) The stirring head revolving body (30) moves along a preset route to drive the conical stirring head (35) to stir friction welding.