CN108453203B

CN108453203B - Die forging device for amorphous alloy die casting, amorphous alloy part, forming equipment and forming method thereof

Info

Publication number: CN108453203B
Application number: CN201710089590.3A
Authority: CN
Inventors: 敬华伟; 樊秀兰; 秦侠
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2017-02-20
Filing date: 2017-02-20
Publication date: 2020-06-19
Anticipated expiration: 2037-02-20
Also published as: CN108453203A

Abstract

The invention discloses a die forging device for an amorphous alloy die casting, an amorphous alloy part, and forming equipment and a forming method thereof. Wherein, an open pore structure is formed on the amorphous alloy die casting, and the die forging device comprises a vacuum box, a limiting component, a die pressing component and a heating component; the vacuum box is internally provided with a vacuum cavity; the limiting assembly is fixedly arranged in the vacuum cavity and is provided with a cavity for placing an amorphous alloy die casting; the die pressing component is movably arranged in the vacuum cavity relative to the limiting component and comprises a pressing head matched with the shape of an opening structure on the amorphous alloy die casting fixed in the cavity; the heating assembly is disposed within the vacuum chamber for controlling a temperature in the vacuum chamber. The die forging device can effectively overcome the main defect of influence on mechanical properties caused by a die casting process, eliminate the internal stress of parts, enable the internal structure of amorphous alloy parts to be more compact, improve the mechanical properties of the parts and prolong the service life of the parts.

Description

Die forging device for amorphous alloy die casting, amorphous alloy part, forming equipment and forming method thereof

Technical Field

The invention relates to the field of amorphous alloy part forming, in particular to an amorphous alloy die casting die forging device, an amorphous alloy part, forming equipment and a forming method thereof.

Background

Amorphous alloys, also known as metallic glasses, are metallic solids with long range disorder, usually obtained by rapidly cooling a metal melt, originally invented in 1960 by Duwez in the united states. The atoms of the amorphous alloy are in disordered arrangement, so that the defects of vacancies, dislocations, grain boundaries, stacking faults and the like in the crystalline alloy are avoided, and the characteristics ensure that the amorphous alloy has excellent corrosion resistance, high strength, high hardness, high wear resistance, high fatigue resistance, complete plasticity in yield and no work hardening phenomenon, and also shows excellent soft and hard magnetic properties, superconducting properties and the like, thereby having potential application prospects in many fields.

At present, a typical forming process of amorphous alloy is die-casting forming, for example, in chinese patent publication No. CN102527982A, an amorphous alloy die-casting device and an amorphous alloy die-casting process are disclosed, and specifically, the amorphous alloy die-casting device is disclosed to include: a fixed mold and a movable mold that are closable and openable and define a mold cavity therebetween when both are closed; a closed bin with a closed chamber defined therein and a feeding port; the protective gas supply device is connected with the closed bin and used for supplying protective gas into the closed chamber, and the protective gas in the closed chamber is in positive pressure; the melting container is arranged in the closed bin and is used for receiving and melting the amorphous alloy added from the feeding port; an injection cylinder communicating with the die cavity and having a melt inlet; an injection plug used for injecting the molten amorphous alloy melt into the die cavity is arranged in the injection cylinder; the driving device is connected with the injection plug and used for driving the injection plug to move in the injection cylinder. The method comprises placing large amorphous alloy block into vacuum chamber of equipment through feeding port, heating for melting, pouring into injection cylinder communicated with die cavity, driving injection plug, and pressing molten amorphous liquid into die cavity for molding.

Another typical forming process of amorphous alloy is die forging forming, for example, chinese patent publication No. CN1456401 discloses a superplastic die forging forming device and method for amorphous alloy precision parts, and specifically discloses that the device consists of three parts, namely a vacuum furnace, a replaceable pressure head and a die; the replaceable pressure head consists of an inner pressure head, an outer pressure head, a slide block and a connecting seat, and the die consists of a die and an ejection mechanism. The process is that the blank and the mould are placed in a vacuum furnace, when the vacuum degree reaches 8 multiplied by 10^-3When Pa is needed, heating is started, and the heating speed is 0.5-3.0 ℃/s; the heating temperature is between Tg and Tx; forming strain rate in the range of 1X 10^-2～5×10^-4S^-1. The method is a method for preparing the amorphous part by putting a large amorphous blank into a mold, putting the mold into a vacuum chamber, vacuumizing and heating the mold in the vacuum chamber, introducing inert gas for protection and cooling.

However, the existing amorphous alloy forming process has the following defects: (1) non-alloy prepared by die-castingThe defects of air bubbles, air holes, shrinkage cavities, slag holes and the like inevitably exist in the metal part, so that the mechanical property of the amorphous alloy is seriously influenced when the amorphous alloy is used as a stressed part; (2) in the technological process of die forging forming amorphous alloy part, the part to be produced is not complicated, and the forming strain rate is 1X 10^-2～5×10^-4S^-1Therefore, the process method is not suitable for preparing amorphous alloy parts with large size and complex structure; and when the process method is adopted to prepare small-size parts, the forming time is too long, the production efficiency is too low, the cost is too high, and the process method is not suitable for mass production.

Disclosure of Invention

The invention aims to provide an amorphous alloy die casting die forging device, an amorphous alloy part, and forming equipment and a forming method thereof, so as to improve the production efficiency and improve the product quality of amorphous alloy.

In order to achieve the above object, according to a first aspect of the present invention, there is provided a die forging apparatus for an amorphous alloy die casting having an open-cell structure formed thereon, the die forging apparatus comprising: the vacuum box, the limiting component, the mould pressing component and the heating component are arranged on the vacuum box; the vacuum box is internally provided with a vacuum cavity; the limiting assembly is fixedly arranged in the vacuum cavity and is provided with a cavity for placing an amorphous alloy die casting; the die pressing assembly is movably arranged in the vacuum cavity relative to the limiting assembly and comprises a pressing head matched with the shape of an opening structure on the amorphous alloy die casting fixed in the cavity; the heating assembly is disposed within the vacuum chamber for controlling a temperature in the vacuum chamber.

According to a second aspect of the invention, an amorphous alloy part forming device is provided, and comprises a die-casting forming device for preparing an amorphous alloy die casting and an amorphous alloy die casting die forging device according to the invention for performing superplastic die forging finish machining on the amorphous alloy die casting.

According to a third aspect of the present invention, there is provided an amorphous alloy part forming method, comprising the steps of: s1, providing an amorphous alloy die casting; and S2, performing superplastic die forging finish machining on the amorphous alloy die casting in the die forging device for the amorphous alloy die casting according to the invention.

According to a fourth aspect of the invention, an amorphous alloy part is provided, the amorphous alloy die casting being prepared by the method according to the invention.

By applying the die forging device for the amorphous alloy die casting, the amorphous alloy part, the forming equipment and the forming method thereof, disclosed by the invention, the amorphous alloy die casting is subjected to super-plastic die forging finish machining, so that the main defect of influencing the mechanical property caused by a die casting process can be effectively overcome, the internal stress of the part is eliminated, the internal structure of the amorphous alloy part is more compact, the mechanical property of the part is improved, and the service life of the part is prolonged; and the method can carry out shaping treatment on the overall dimension of the amorphous alloy die casting, improves the dimensional precision of parts, and is also suitable for producing amorphous alloy parts with complex shapes and large sizes.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 shows a schematic structural diagram of an amorphous alloy die casting according to an embodiment of the invention;

FIG. 2 shows a schematic structural diagram of an amorphous alloy die casting die forging device according to an embodiment of the invention;

3-6 are schematic flow charts in the superplastic forging finish machining process by using an amorphous alloy die casting die forging device according to an embodiment of the invention; wherein:

FIG. 3 shows a schematic structural diagram of the amorphous alloy die casting die forging device when the pressure head is located at a first position A after the amorphous alloy die casting is placed into the vacuum chamber of the die forging device;

FIG. 4 shows a schematic structural diagram of an amorphous alloy die casting die forging device when a driving pressure head moves from a first position A to a second position B;

FIG. 5 shows a schematic structural diagram of the amorphous alloy die casting die forging device when the driving pressure head moves from the second position B to the third position C;

FIG. 6 shows a schematic structural diagram of the amorphous alloy die casting die forging device when the driving ram moves back to the first position A from the third position C and drives the ejector rod to eject the amorphous alloy piece obtained through the super-plastic die forging finish machining;

fig. 7 shows a schematic structural diagram of a flexible gear of an amorphous alloy part prepared according to embodiment 1 of the present invention.

Description of the reference numerals

10 is an amorphous alloy die casting, 11 is an inner side wall surface of the amorphous alloy die casting, 12 is a bottom wall of the amorphous alloy die casting, 20 is a vacuum box, 21 is a box body, 22 is a base, 30 is a limiting component, 31 is a cavity, 32 is a first heating plate, 321 is a bottom wall surface of a limiting groove in the first heating plate, 33 is a first heat insulation plate, 34 is a first die holder, 35 is an ejector rod, 40 is a die pressing component, 41 is a pressing head, 411 is an outer side wall surface of the pressing head, 412 is a bottom wall surface of the pressing head, 42 is a second heating plate, 421 is a limiting pressure plate, 422 is a pressing head surface of the limiting pressure plate, 423 is a limiting lug, 43 is a second heat insulation plate, 44 is a second die holder, 45 is a pressing rod, 50 is a heating component, 60 is a guide column, and 70 is a component taking and.

Detailed Description

The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

Aiming at the defect that the mechanical property of amorphous alloy is seriously influenced when the amorphous alloy is used as a stressed part because the defect of air bubbles, air holes, shrinkage cavities, slag holes and the like which are inevitable in the amorphous alloy part prepared by die-casting molding in the prior art is overcome, the invention provides a die forging device for the amorphous alloy die-casting part, as shown in figure 1, an open pore structure is formed on an amorphous alloy die-casting part 10, as shown in figure 2, the die forging device comprises: a vacuum box 20, a limiting component 30, a molding component 40 and a heating component; the vacuum box is internally provided with a vacuum cavity; the limiting assembly 30 is fixedly arranged in the vacuum cavity and is provided with a cavity 31 for placing the amorphous alloy die casting 10; the die pressing component 40 is movably arranged in the vacuum cavity relative to the limiting component 30 and comprises a pressing head 41 matched with the shape of an opening structure on the amorphous alloy die casting 10 fixed in the cavity 31; the heating assembly is disposed within the vacuum chamber 20 for controlling the temperature in the vacuum chamber.

According to the die forging apparatus of the present invention, preferably, the inner sidewall surface 11 of the opening structure in the amorphous alloy die casting 10 has an outward draft angle, the outer sidewall surface 411 of the indenter 41 has an inward draft angle, and the absolute value of the draft angle of the outer sidewall surface 411 of the indenter 41 is equal to the absolute value of the draft angle of the inner sidewall surface 11 of the corresponding opening structure in the amorphous alloy die casting 10. Through reasonable matching the outside wall 411 of the pressure head 41 and the draft angle of the inner wall 11 of the corresponding open pore structure in the amorphous alloy die casting 10 make the pressure head 41 move up and down, the outside wall 411 of the pressure head is always parallel to the inner wall 11 of the corresponding open pore structure in the amorphous alloy die casting 10, so that the pressure head can smoothly extend into the corresponding open pore structure in the amorphous alloy die casting 10.

According to the swaging apparatus of the present invention, it is preferable that the dimension of the diameter of the ram 41 in the cross section perpendicular to the moving direction thereof is larger than the dimension of the diameter of the amorphous alloy die cast 10 in the cross section at the corresponding position, and the difference between the dimensions is preferably 0.15 to 0.25 mm. Through making both have certain size difference, be favorable to making pressure head 41 in the in-process that moves down, the outer wall surface 411 of pressure head can extrude the interior lateral wall face 11 of corresponding trompil structure in the amorphous alloy die casting 10 to make amorphous alloy die casting internal structure pressed more closely, and then reduce defects such as bubble, gas pocket, shrinkage cavity and slag notch wherein.

According to the swaging apparatus of the present invention, it is preferable that the shape of the cavity 31 matches the shape of the amorphous alloy die casting 10, and when the amorphous alloy die casting 10 is installed in the cavity 31, a single-sided gap of 0.03 to 0.05 is formed between the inner side wall surface of the cavity 31 and the outer side wall surface of the amorphous alloy die casting 10. Through making to have the clearance between the inside wall face of die cavity 31 and the outside wall face of amorphous alloy die casting 10, on the one hand can be with smooth putting into die cavity 31 of amorphous alloy die casting 10, on the other hand is favorable to making pressure head 41 in the inside removal of corresponding trompil structure in the amorphous alloy die casting 10, outside wall face 411 of pressure head 41 can extrude the inside wall face 11 of corresponding trompil structure in the amorphous alloy die casting 10 for amorphous alloy die casting 10 outwards expands, after the outside wall face of amorphous alloy die casting 10 contacted the inside wall face of die cavity 31, no longer outwards expands. In the process, the amorphous alloy die casting 10 is extruded to enable the internal structure to be pressed more tightly, and further defects such as air bubbles, air holes, shrinkage cavities, slag holes and the like in the amorphous alloy die casting are reduced.

According to the swaging apparatus of the present invention, it is preferable that the heating unit includes a first heating plate 32 and a second heating plate 42, the first heating plate 32 is detachably provided in the stopper unit 30, the cavity 31 is formed in the first heating plate 32, or a die having the cavity 31 is installed in the first heating plate 32; the second heating plate 42 is installed in the molding assembly 40, and the press head 41 is detachably installed on the second heating plate 42. The arrangement of the first heating plate 32 and the second heating plate 41 is not only beneficial to optimizing the structure of the heating assembly, but also beneficial to controlling the temperature of the die cavity 31 and the pressure head 41 and the amorphous alloy die casting 10 placed in the die cavity 31.

According to the swaging apparatus of the present invention, it is preferable that the first heating plate 32 and the second heating plate 42 include a plate body and a heating member 50 fixed in the plate body, respectively. There is no particular requirement for the selection of the heating element 50, which may be an electric heating rod or an induction heating rod. In the present invention, there is no special requirement for the arrangement of the heating elements 50 in the first heating plate 32, as long as the heating elements are uniformly distributed on the periphery of the cavity 31; there is no particular requirement for the arrangement of the heating members in the second heating plate 42, as long as they are uniformly distributed in the second heating plate 42.

According to the swaging apparatus of the present invention, preferably, the swaging assembly 40 includes a limit pressing plate 421, the limit pressing plate 421 is fixed at a central position of the second heating plate 42, a side of the limit pressing plate 421 away from the second heating plate 42 forms a ram surface 422, and the ram 41 is fixed at a central position of the ram surface 422; the limiting assembly 30 further comprises a limiting groove formed in the central portion of the first heating plate 32, a parting surface 321 is formed at the bottom of the limiting groove, and the cavity 31 is formed in the central position of the parting surface 321; the limiting pressure plate is matched with the limiting groove structure, and when the pressure head surface 422 is attached to the die parting surface 321, the limiting component 30 and the die pressing component 40 form a die closing structure. Through setting up spacing clamp plate 421 and the spacing recess that forms on first hot plate 32 for when mould pressing subassembly 40 takes place relative motion for spacing subassembly 30, when the pressure head face 422 of spacing clamp plate 421 and the die parting face 321 of spacing recess supported, stop motion, and then realize through the distance between the control pressure head 41 and the die cavity 31 diapire face during the compound die, with the thickness of the diapire 12 of the amorphous alloy part that controls and prepare. Preferably, the thickness of the bottom wall 12 of the amorphous alloy die casting 10 is larger than the distance between the pressure head 41 and the bottom wall surface of the cavity 31 during die assembly, the difference between the two is 0.1-0.2mm, and the bottom wall 12 of the amorphous alloy die casting 10 is extruded through the bottom wall surface 412 of the pressure head 41, so that the bottom wall structure of the amorphous alloy part is pressed more tightly, and the defects of bubbles, air holes, shrinkage cavities, slag holes and the like in the amorphous alloy part are further reduced.

According to the swaging apparatus of the present invention, preferably, the molding assembly 40 includes a plurality of limiting protrusions 423 fixed on the second heating plate 42, the limiting protrusions 423 are symmetrically disposed on two sides of the pressing head 41, and preferably, the height of each limiting protrusion 423 is the same as the height of the limiting pressing plate 421; the limiting assembly 30 further includes a plurality of limiting openings formed on the first pressing plate 32 and corresponding to the limiting protrusions 423 one to one, and the limiting protrusions 423 are structurally matched with the limiting openings. Through set up a plurality of spacing lugs 423 in the both sides of pressure head 41, through make it with be located spacing trompil on the spacing lug 423 corresponds the combination, is favorable to making the axle center of pressure head coaxial with the axle center of die cavity, and the part wall thickness after the die forging is even, and material tissue density is even, and the size is accurate.

According to the swaging apparatus of the present invention, preferably, the limiting assembly 30 includes a first heat-shielding plate 33, and the first heating plate 32 is mounted on the first heat-shielding plate 33; the molding assembly 40 includes a second heat insulation plate 43 therein, and the second heating plate 42 is mounted on the second heat insulation plate 43. Through setting up first heat insulating board 33 and second heat insulating board 43, be favorable to blockking the outside quick conduction of the produced heat energy of first hot plate 32 and second hot plate 42, and then concentrate the heat, avoid heat energy to dispel outward, the pressure head that makes and the die cavity are in the settlement temperature value all the time, and then realize energy-conserving effect.

According to the swaging apparatus of the present invention, the limiting assembly 30 preferably includes a first die holder 34, and the first thermal baffle 33 is mounted on the first die holder 34; the molding assembly 40 includes a second mold base 44, and the second heat shield 43 is mounted on the second mold base 44.

In the swaging apparatus according to the present invention, the second die holder 44 is preferably provided with a guide post 60 extending toward the first die holder 34; a guide through hole matched with the guide column 60 in size is formed in the first die holder 43, and the first die holder 43 is connected with the guide column in a matched mode through the guide through hole.

According to the swaging apparatus of the present invention, a pressing rod 45 is preferably included in the swaging assembly 40, and one end of the pressing rod 45 extends to the outside of the vacuum box 20, and the other end is connected to the second die holder 44 to drive the swaging assembly 40 to move relative to the limiting assembly 30.

According to the swaging apparatus of the present invention, preferably, the limiting member 30 includes a ram 35 movable relative to the cavity 31, one end of the ram 35 extends to the outside of the vacuum box 20, and the other end passes through the first die holder 34, the first heat insulation plate 33 and the first heating plate 32 to form at least a part of the bottom wall surface of the cavity 31, or support the die having the cavity 31.

According to the swaging apparatus of the present invention, preferably, the vacuum box 20 includes a box body 21 and a base 22, and the stopper assembly 40 is fixed to the base 22; the housing 21 includes a top plate disposed opposite the base 22, and the molding assembly 30 is movably mounted on the top plate.

Meanwhile, the invention also provides amorphous alloy part forming equipment which comprises a die-casting forming device for preparing the amorphous alloy die casting and an amorphous alloy die casting die forging device for performing superplastic die forging finish machining on the amorphous alloy die casting.

The forming equipment for the amorphous alloy part, provided by the invention, is mainly used for combining die-casting forming and precision die forging forming together so as to improve the production efficiency and improve the product quality of the amorphous alloy. There is no particular requirement for the die-casting forming device, so long as it is used in combination with the amorphous alloy die-casting die forging device according to the present invention. The die casting apparatus used in the present invention may be any commercially available apparatus, and for example, an amorphous alloy die casting apparatus disclosed in chinese patent application publication No. CN102527982A may be used.

In addition, the invention also provides a method for forming the amorphous alloy part, which comprises the following steps: s1, providing an amorphous alloy die casting; and S2, performing superplastic die forging finish machining on the amorphous alloy die casting in the die forging device for the amorphous alloy die casting according to the invention.

The forming method of the amorphous alloy part provided by the invention is mainly characterized in that the die-casting forming and the precision die forging forming are combined together, so that the production efficiency is improved and the product quality of the amorphous alloy is improved. The die-casting forming method has no special requirement, and the die-casting forming method can be used in combination with the superplastic die-forging finishing of the amorphous alloy die casting die-forging device. The die casting method used in the present invention may refer to a conventional method in the art, and for example, the amorphous alloy die casting method disclosed in chinese patent publication No. CN102527982A may be used.

According to the method of the present invention, preferably, the S2 includes: s21, evacuating a vacuum chamber of the swaging apparatus, and introducing an inert gas so that a gas pressure in the vacuum chamber reaches a predetermined gas pressure, wherein the predetermined gas pressure is greater than an atmospheric pressure, and preferably the predetermined gas pressure is 1.01 to 1.05 atmospheric pressures; s22, controlling a heating assembly to heat, and enabling the temperature in the vacuum cavity to reach a supercooling region (Tg-Tx) of the amorphous alloy die casting; s23, placing the amorphous alloy die casting into a cavity of a limiting assembly; and S24, driving a pressure head in the die pressing assembly to move, and performing superplastic die forging finish machining on the amorphous alloy die casting placed in the cavity of the limiting assembly.

According to the method of the invention, preferably, in the step S23, the amorphous alloy die casting is placed into the cavity of the limiting component under the condition of continuously introducing the inert gas. By continuously introducing the inert gas, the pressure in the vacuum chamber is always kept larger than the outside, and when the piece taking and placing port 70 of the vacuum chamber is opened in a short time, the external gas (oxygen) cannot enter the vacuum chamber, so that the part can be prevented from being oxidized when high-temperature die forging is performed. In practice, a sealing member (not shown) is provided between the pick-and-place port 70 and the vacuum box.

According to the method of the invention, preferably, after the amorphous alloy die casting is placed into the cavity of the die forging device in S24, the pressure head in the die pressing assembly is driven to move after the amorphous alloy die casting is preheated to the temperature reaching the supercooling region, and the preheating time is preferably 6-8 min.

According to the method of the invention, preferably, in the step S23, after the amorphous alloy die casting is placed into the cavity of the limiting component to form the structure shown in fig. 3; the S24 includes: s241, driving the pressure head to move from a first position A far away from the limiting assembly to a second position B in primary contact with the amorphous alloy die casting to form a structure shown in FIG. 4; s242, under a preset forming strain speed, moving the pressure head from the second position B to a third position C where the limiting assembly 30 and the molding assembly 40 are in a mold clamping state at a preset pressure, and forming the structure shown in FIG. 5; and S243, after pressure maintaining treatment for a preset time, driving the pressure head to move back to the first position A from the third position C, and driving the ejector rod to eject the amorphous alloy piece obtained through superplastic die forging and finishing to form the structure shown in fig. 6.

According to the method of the present invention, preferably, the predetermined molding strain rate is 1 × 10^-2～5×10^-4S^-1(ii) a The predetermined pressure is 400-500 MPa; the preset time is 1-5 min. The preset forming strain speed, the preset pressure and the preset time are controlled within the ranges, so that the product is smooth in surface, fine in internal structure, reliable in die forging and forming and accurate in size.

According to the method of the invention, the components and contents of the amorphous alloy are not particularly required, and the conventional components and contents in the die-casting forming and die-forging forming in the prior art can be referred. For example, the amorphous alloy is Zr_aAl_bBe_cCu_dM_eWherein M is one or more elements of Nb, Sc, Ta, Ni, Co, Y, Ag, Fe, Sn, Hf, Ti and rare earth elements; a. b, c, d and e are atomic percentages, a is more than or equal to 30 and less than or equal to 70, b is more than or equal to 3 and less than or equal to 35, c is more than or equal to 3 and less than or equal to 35, d is more than or equal to 3 and less than or equal to 40, and e is more than or equal to 5 and less than or equal to 30. More preferably, the amorphous alloy contains impurity elements, wherein the content of the impurity elements is not higher than 5% by atomic percentage.

The invention also provides an amorphous alloy part, and the amorphous alloy die casting is prepared by the method. The amorphous alloy part provided by the invention has a more compact internal structure, the mechanical property of the part is improved, and the service life of the part is prolonged; and the overall dimension of the amorphous alloy die casting can be shaped, and the dimensional precision of the part is improved.

The advantageous effects of the present application will be further described below with reference to specific examples and comparative examples.

In the following embodimentsIn the examples and comparative examples, Zr having a diameter of 5mm was used₆₅Al₄Cu₂₅Ni₆The bulk amorphous alloy rod is used as a molding material (Vickers hardness of 450-550Hv, bending strength of 2350MPa, tensile strength of 1000MPa and compressive strength of 1500 MPa.

In the following examples and comparative examples, the amorphous alloy part to be molded is a flexspline blank as shown in fig. 7, and the flexspline blank comprises a bottom wall and an annular side wall perpendicularly connected with the periphery of the bottom wall, and an annular reinforcing part protruding outwards is formed on one side of the annular side wall far away from the bottom wall as shown in fig. 7. The inner wall surface of the annular side wall of the flexible wheel blank body is provided with a flaring structure extending outwards from the bottom wall, the diameter d1 of the end connected with the bottom wall is 10.64cm, and the diameter d2 of the end extending outwards is 11.38 cm; the extension direction of the outer wall surface of the annular side wall is parallel to the axial direction of the flexible wheel, and the diameter d3 of the annular side wall is 11.64 cm; the side wall height h1 of the flexible gear blank is 4.23cm, and the bottom wall thickness h2 of the flexible gear blank is 0.44 cm; the outer wall surface of the annular reinforcing portion extends in a direction parallel to the axial direction of the flexspline, and has a diameter d4 of 12.11 cm.

Examples

The die forging device for the amorphous alloy die casting, the amorphous alloy part, the forming equipment and the forming method thereof have the beneficial effects.

(1) Preparation of amorphous alloy die casting

By adopting the amorphous alloy die-casting equipment with the structure shown in figure 1 in the specification and the drawing of the Chinese patent with the publication number of CN102527982A, the amorphous alloy die-casting process comprises the following steps:

purifying a closed cavity of a closed bin of amorphous alloy die casting equipment to enable the concentration of harmful gas in the closed cavity to be lower than 1000 ppm; supplying a shielding gas (helium) into the closed chamber and maintaining the shielding gas in the closed chamber at a positive pressure between 1 atmosphere and 1.1 atmosphere; feeding the large amorphous alloy rod into a melting container positioned in the closed cavity from a feeding port on the closed cavity for melting to obtain molten amorphous alloy, and feeding the protective gas in the closed cavity into the melting container through the feeding port to overflow from the feeding port; feeding the molten amorphous alloy from the melting vessel into a shot sleeve; pressing the molten amorphous alloy from the pressing and injecting cylinder into a die cavity defined by a fixed die and a movable die of the amorphous alloy die casting equipment for forming; and opening the fixed die and the movable die to take out the formed amorphous alloy die casting from a part taking port of the non-gold alloy die casting device.

The die casting comprises a bottom wall and an annular side wall perpendicularly connected with the periphery of the bottom wall, and an annular reinforcing part protruding outwards is formed on one side, far away from the bottom wall, of the annular side wall. The inner wall surface of the annular side wall of the flexible wheel blank is provided with an outward-expanding structure extending outwards from the bottom wall, the diameter d1 of one end of the annular side wall connected with the bottom wall is 10.44cm, the diameter d2 of one end of the annular side wall extending outwards is 11.18cm, the extending direction of the outer wall surface of the annular side wall is parallel to the axial direction of the flexible wheel, and the diameter d3 of the annular side wall is 11.66 cm; the extension direction of the outer wall surface of the annular side wall is parallel to the axial direction of the flexible wheel, and the diameter d3 of the annular side wall is 11.58 cm; the side wall height h1 of the flexible gear blank is 4.13cm, and the bottom wall thickness h2 of the flexible gear blank is 0.54 cm; the outer wall surface of the annular reinforcing portion extends in a direction parallel to the axial direction of the flexspline, and has a diameter d4 of 12.19 cm.

(2) Preparation of amorphous alloy parts

Adopting the die forging device shown in FIG. 2, vacuumizing a vacuum chamber of the die forging device, and introducing inert gas (helium gas) to make the air pressure in the vacuum chamber reach 1.01-1.05 atmospheric pressure; s22, controlling a heating assembly to heat to 450 ℃ (to reach a supercooling region of the amorphous alloy die casting); s23, under the condition that inert gas is continuously introduced, placing the prepared amorphous alloy die casting into a cavity of a limiting assembly (the amorphous alloy die casting is matched with the prepared amorphous alloy die casting in structure, and when the amorphous alloy die casting is installed in the cavity, a single-side gap of 0.03mm exists between the inner side wall surface of the cavity and the outer side wall surface of the amorphous alloy die casting), so as to form a structure shown in FIG. 3; s24, preheating the amorphous alloy die casting for 6min, and driving a pressure head (and) in the die pressing assemblyThe prepared amorphous alloy die casting is adapted to the internal open pore structure, the absolute value of the draft angle of the outer side wall surface of the pressure head and the absolute value of the inner side wall surface of the corresponding open pore structure in the amorphous alloy die casting are equal, the diameter of the front end of the pressure head facing to the limiting component is 10.64cm, the diameter of the rear end of the pressure head is 11.38cm), the pressure head moves from a first position A far away from the limiting component to a second position B in primary contact with the amorphous alloy die casting, the structure is formed as shown in figure 4, and the forming strain speed is 1.5 multiplied by 10^-3S^-1Moving the pressure head from the second position B to a third position C which cannot move under the pressure of 400MPa to form a structure shown in FIG. 5; s243, maintaining the pressure for 2min, driving the pressure head to move back to the first position A from the third position C, and driving the ejector rod to eject the amorphous alloy piece obtained by superplastic die forging and finishing to form the structure shown in figure 6; and taking out the amorphous alloy piece obtained by the superplastic die forging and finishing, and marking as the amorphous alloy piece S1.

Comparative example 1

By adopting the amorphous alloy die-casting equipment with the structure shown in figure 1 in the specification and the attached drawing of the Chinese patent with the application number of 201110421420.3, the amorphous alloy die-casting process comprises the following steps: an amorphous alloy part (die cast) was obtained in the same manner as in example 1 and was designated as D1.

And (3) testing:

the amorphous alloy parts (flexspline bodies) S1 and D1 and the amorphous alloy die castings prepared in the foregoing examples and comparative examples were subjected to performance tests, the test methods and results are shown in table 1.

Table 1.

Test items	S1	D1	Test method
				Vickers hardness (Hv)	515	498	Pressing in method
Compressive strength (Mpa)	1500	1420	Compression resistance testing machine
				Density (g/cm)³)	6.83	6.75	Density tester
Service life (hours)	11000	8500	Life test machine
				Surface defects (bubbles, pores, shrinkage cavities, slag holes)	Is free of	Small amount of	X-ray inspection

As can be seen from the results in table 1, compared to the amorphous alloy part D1 formed by the die casting process, the amorphous alloy part S1 prepared by the method of the present invention has substantially no pores, shrinkage cavities, etc., so that the internal structure of the part is more compact (density is optimized), and the mechanical properties (hardness and compressive strength) and the service life of the part are improved. In addition, compared with the existing superplastic die forging forming method, the method provided by the invention has the advantages that the application range is increased, and the method can be suitable for producing parts with complex shapes and large sizes.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.

Claims

1. An amorphous alloy die casting die forging device, an open pore structure is formed on an amorphous alloy die casting (10), and the die forging device is characterized by comprising: the vacuum box (20), the limiting component (30), the mould pressing component (40) and the heating component; the vacuum box is internally provided with a vacuum cavity; the limiting assembly (30) is fixedly arranged in the vacuum cavity and is provided with a cavity (31) for placing the amorphous alloy die casting (10); the die pressing component (40) is movably arranged in the vacuum cavity relative to the limiting component (30) and comprises a pressing head (41) matched with the shape of an opening structure on the amorphous alloy die casting (10) fixed in the cavity (31); the heating assembly is disposed within the vacuum chamber (20) for controlling the temperature in the vacuum chamber.

2. The die forging apparatus according to claim 1, wherein an inner sidewall surface (11) of the open-cell structure in the amorphous alloy die casting (10) has an outward draft angle, an outer sidewall surface (411) of the ram (41) has an inward draft angle, and the absolute values of the draft angles of the outer sidewall surface (411) of the ram (41) and the inner sidewall surface (11) of the corresponding open-cell structure in the amorphous alloy die casting (10) are equal.

3. The die forging apparatus according to claim 1, wherein the shape of said cavity (31) matches the shape of said amorphous alloy die casting (10), and when said amorphous alloy die casting (10) is installed in said cavity (31), a single-sided gap of 0.03-0.05mm exists between the inner side wall surface of said cavity (31) and the outer side wall surface of said amorphous alloy die casting (10).

4. The swaging apparatus of any of claims 1 to 3, wherein the heating assembly comprises a first heating plate (32) and a second heating plate (42), the first heating plate (32) being detachably provided in the restraining assembly (30), the cavity (31) being formed in the first heating plate (32), or a die having the cavity (31) being mounted in the first heating plate (32); the second heating plate (42) is installed in the molding assembly (40), and the press head (41) is detachably installed on the second heating plate (42).

5. The swaging apparatus of claim 4, wherein the first and second heating plates (32, 42) each include a sheet material body and a heating element (50) secured therein.

6. The swaging apparatus of claim 4, wherein the swaging assembly (40) comprises a limiting pressure plate (421), the limiting pressure plate (421) is fixed at a central position of the second heating plate (42), a side of the limiting pressure plate (421) far away from the second heating plate (42) forms a ram surface (422), and the ram (41) is fixed at a central position of the ram surface (422); the limiting assembly (30) further comprises a limiting groove formed in the central part of the first heating plate (32), a die parting surface (321) is formed at the bottom of the limiting groove, and the die cavity (31) is formed in the central position of the die parting surface (321); the limiting pressure plate (421) is matched with the limiting groove structure, and when the pressure head surface (422) is attached to the die parting surface (321), the limiting component (30) and the die pressing component (40) form a die closing structure.

7. The swaging apparatus of claim 6, wherein the die assembly (40) comprises a plurality of restraining projections (423) fixed to the second heating plate (42), the plurality of restraining projections (423) being symmetrically disposed on both sides of the ram (41); the limiting assembly (30) further comprises a plurality of limiting open holes which are formed in the first heating plate (32) and correspond to the limiting convex blocks (423) one to one, and the limiting convex blocks (423) are matched with the limiting open holes in structure.

8. The swaging apparatus of claim 7, wherein a height of each of the restraining projections (423) is the same as a height of the restraining platen (421).

9. The swaging apparatus of claim 4, wherein the restraining assembly (30) comprises a first heat shield (33), the first heating plate (32) being mounted on the first heat shield (33); the molding assembly (40) comprises a second heat insulation plate (43), and the second heating plate (42) is arranged on the second heat insulation plate (43).

10. The swaging apparatus of claim 9, wherein the stop assembly (30) comprises a first die shoe (34), the first heat shield (33) being mounted on the first die shoe (34); the molding assembly (40) comprises a second mold base (44), and the second heat insulation plate (43) is arranged on the second mold base (44).

11. The swaging apparatus of claim 10, wherein the second die holder (44) mounts thereon a guide post (60) extending toward the first die holder (34); the first die holder (34) is provided with a guide through hole matched with the guide column (60) in size, and the first die holder (34) is connected with the guide column in a matched mode through the guide through hole.

12. The swaging apparatus of claim 10, wherein the swaging assembly (40) includes a compression bar (45) therein, the compression bar (45) extending to an outside of the vacuum box (20) at one end and being coupled to the second die shoe (44) at another end to drive the swaging assembly (40) to move relative to the stop assembly (30).

13. The swaging apparatus of claim 10, wherein the limiting assembly (30) comprises a ram (35) movable relative to the cavity (31), one end of the ram (35) extends to the outside of the vacuum box (20), and the other end passes through the first die holder (34), the first heat shield (33) and the first heating plate (32) to form at least a partial bottom wall surface of the cavity (31) or to support the mold having the cavity (31).

14. The swaging apparatus of claim 1, wherein the vacuum box (20) comprises a box body (21) and a base (22), the stop assembly (30) being fixed to the base (22); the box body (21) comprises a top plate which is arranged opposite to the base (22), and the molding assembly (40) is movably arranged on the top plate.

15. An amorphous alloy part forming apparatus, characterized in that the amorphous alloy part forming apparatus comprises a die casting forming device for preparing an amorphous alloy die casting and the amorphous alloy die casting die forging device of any one of claims 1 to 13 for performing superplastic die forging finish machining on the amorphous alloy die casting.

16. A method for forming an amorphous alloy part, comprising the steps of:

s1, providing an amorphous alloy die casting;

s2, subjecting the amorphous alloy die casting to superplastic forging finishing in the amorphous alloy die casting forging device of any one of claims 1 to 14.

17. The method of claim 16, wherein the S2 includes:

s21, vacuumizing a vacuum cavity of the die forging device, and introducing inert gas to enable the air pressure in the vacuum cavity to reach a preset air pressure, wherein the preset air pressure is greater than the atmospheric pressure;

s22, controlling a heating assembly to heat, and enabling the temperature in the vacuum cavity to reach the supercooling region of the amorphous alloy die casting;

s23, placing the amorphous alloy die casting into a cavity of a limiting assembly;

and S24, after the amorphous alloy die casting is preheated to a temperature reaching the supercooling region, driving a pressure head in the die pressing assembly to move, and performing superplastic die forging finish machining on the amorphous alloy die casting placed in the cavity of the limiting assembly.

18. The method of claim 17, wherein the predetermined pressure is 1.01-1.05 atmospheres.

19. The method of claim 17, wherein in the step S23, the amorphous alloy die casting is placed into the cavity of the limiting component under the condition of continuously introducing inert gas.

20. The method of claim 17, wherein in S24, after the amorphous alloy die casting is placed into the cavity of the die forging device, the ram in the die assembly is driven to move after the amorphous alloy die casting is preheated to the temperature reaching the supercooling region.

21. The method of claim 17, wherein the preheating time is 6-8 min.

22. The method of claim 17, wherein the S24 includes:

s241, driving the pressure head to move from a first position (A) far away from the limiting assembly to a second position (B) in primary contact with the amorphous alloy die casting;

s242, under a preset forming strain speed, moving the pressure head from the second position (B) to a third position (C) where the limiting assembly and the mould pressing assembly are in a mould closing state at a preset pressure;

and S243, after the pressure maintaining treatment is carried out for a preset time, driving the pressure head to move back to the first position (A) from the third position (C).

23. The method of claim 22, wherein the predetermined forming strain rate is 1 x 10^-2～5×10^-4S^-1(ii) a The predetermined pressure is 400-500 MPa; the preset time is 1-5 min.

24. An amorphous alloy part, wherein the amorphous alloy die cast part is prepared by the method of any one of claims 16-23.