阅读说明：本技术 一种高性能铝合金铸件无模成型铸造方法 (High-performance aluminum alloy casting dieless forming casting method ) 是由 马正松 马文青 陆定邦 于 2020-04-07 设计创作，主要内容包括：本发明属于金属材料加工成型技术领域,特别涉及一种高性能铝合金铸件无模成型铸造方法,所述的方法包括应用3D打印技术快速制造壳型,采用V法造型方式进行埋箱填实,再采用低压工艺进行浇注；根据本发明提供的实施方案,解决了传统的铸造工艺很难实现的复杂大型金属构件以及小批量的个性化产品的精密铸造,实现近净成型技术,极大提升了铸件的产品质量,改善了生产制造环境,减小了劳动强度,基本可以实现绿色铸造；且本发明提供的工艺技术能够让产品实现结构更加复杂化、性能更优越化、品质更精细化、制造更高效化、性价更合理化,具备较好的应用前景。(The invention belongs to the technical field of metal material processing and forming, and particularly relates to a high-performance aluminum alloy casting die-free forming casting method, which comprises the steps of quickly manufacturing a shell mold by applying a 3D printing technology, embedding and filling the shell mold in a V-method molding mode, and then pouring by adopting a low-pressure process; according to the embodiment provided by the invention, the problem that the traditional casting process is difficult to realize the precise casting of complex large-scale metal components and small-batch individualized products is solved, the near-net-shape forming technology is realized, the product quality of castings is greatly improved, the production and manufacturing environment is improved, the labor intensity is reduced, and the green casting can be basically realized; the process technology provided by the invention can enable the product to have more complicated structure, more superior performance, more refined quality, more efficient manufacturing and more reasonable cost performance, and has better application prospect.)

1. The dieless forming casting method of the high-performance aluminum alloy casting is characterized by comprising the following steps of:

(1) preprocessing a three-dimensional graph of a product, deleting fine characteristics which cannot be cast and molded, after machining allowance is increased on a machining surface, putting the model into a shrinkage mode integrally, designing a pouring system according to the structural characteristics of the product, completing drawing of a three-dimensional graph of the pouring system to obtain a casting process graph of the product, and drawing a three-dimensional model of the sand mold shell by using three-dimensional software;

(2) printing a drawn casting sand mold by using a 3D printer, cleaning accumulated sand, edges, burrs and the like in a printed sand mold cavity, dip-coating a coating on the sand mold, and drying the sand mold in an oven after dip-coating;

(3) molding the baked sand mold to obtain a casting shell mold; laying a layer of PE film on a bottom plate, adsorbing the edge of the film on the periphery of a vacuum sand box by using a magnet, placing a shell mold on the bottom plate, enabling the bottom of the shell mold to be protruded and buckled in a hole on the bottom plate, and buckling and locking the vacuum box on the bottom plate;

(4) adding dry quartz sand into a vacuum sand box until the vacuum sand box is full, scraping a sand surface, covering a layer of PE film, and adsorbing the edge of the film on the periphery of the vacuum sand box by using a magnet;

(5) inserting a vacuum tube on a vacuumizing interface of a vacuum sand box, vacuumizing the vacuum sand box, and keeping the pressure between-0.030 MPa and 0.035 MPa;

(6) transferring the treated aluminum liquid into a crucible, closing a furnace cover of a heat preservation furnace, and putting the heat preservation furnace into a pit;

(7) transferring the pouring sand mold subjected to the V-method quick box burying molding to a pit, and completing butt joint of a liquid lifting pipe and a pouring gate on the sand mold;

(8) sending compressed air into the heat preservation furnace through a compressed air interface, applying pressure to aluminum liquid in the heat preservation furnace to finish pouring operation, and closing the compressed air;

(9) and after the casting is finished, the negative pressure of the vacuum sand box is removed, the dry sand is automatically dispersed, and after the casting is cooled, the 3D printing shell mould on the surface of the casting is removed to obtain the casting blank.

2. The dieless forming casting method for high-performance aluminum alloy castings according to claim 1, wherein in the step (2), the 3D printer prints out casting sand molds, the inner mold sand molds adopt a free-form hollow structure, the outer mold sand molds adopt a free-form structure, the wall thickness of the sand molds is 30-35mm, and the strength is 5.5MPa-6.0 MPa.

3. The dieless-forming casting method for high-performance aluminum alloy castings according to claim 1, wherein in the step (2), the thickness of the sand-type dip coating is 0.5 mm.

4. The dieless mold-forming casting method for high-performance aluminum alloy castings according to claim 1, wherein the baking conditions of the sand molds in the oven in step (2) include a baking temperature of 180 ℃ and a baking time of 4-6 hours.

5. The dieless forming casting method for high performance aluminum alloy castings according to claim 1, wherein in the step (8), the pressure applied by the compressed air to the aluminum liquid in the holding furnace is 0.6MPa to 1.6 MPa.

Technical Field

The invention belongs to the technical field of metal material processing and forming, and particularly relates to a high-performance aluminum alloy casting dieless forming casting method.

Background

The aluminum alloy is a non-ferrous metal material which is most widely applied in industry, has the characteristics of low density, high strength, good plasticity, corrosion resistance, excellent electric and thermal conductivity and the like, plays an important role in the industries such as automobiles, molds, mechanical equipment, ships, aerospace, national defense and military industry and the like, and is one of main structural materials for realizing industrial lightweight.

Disclosure of Invention

The invention aims to provide a high-performance aluminum alloy casting dieless forming casting method, which solves the problems of complex large-scale metal components and small-batch precise casting of personalized products which are difficult to realize by the traditional casting process.

In order to achieve the purpose, the invention adopts the following technical scheme:

a dieless forming casting method for high-performance aluminum alloy castings comprises the following steps:

(1) preprocessing a three-dimensional graph of a product, deleting fine characteristics which cannot be cast and molded, after machining allowance is increased on a machining surface, putting the model into a shrinkage mode integrally, designing a pouring system according to the structural characteristics of the product, completing drawing of a three-dimensional graph of the pouring system to obtain a casting process graph of the product, and drawing a three-dimensional model of the sand mold shell by using three-dimensional software;

(2) printing a drawn casting sand mold by using a 3D printer, cleaning accumulated sand, edges, burrs and the like in a printed sand mold cavity, dip-coating a coating on the sand mold, and drying the sand mold in an oven after dip-coating;

(3) molding the baked sand mold to obtain a casting shell mold; laying a layer of PE film on a bottom plate, adsorbing the edge of the PE film on the periphery of a vacuum sand box by using a magnet, placing a shell mold on the bottom plate, enabling the bottom of the shell mold to be protruded and buckled in a hole in the bottom plate, and buckling and locking the vacuum sand box on the bottom plate;

(4) adding dry quartz sand into a vacuum sand box until the vacuum sand box is full, scraping a sand surface, covering a layer of PE film, and then adsorbing the edge of the PE film on the periphery of the vacuum sand box by using a magnet;

(5) inserting a vacuum tube on a vacuumizing interface of a vacuum sand box, vacuumizing the vacuum sand box, and keeping the pressure between-0.030 MPa and 0.035 MPa;

(6) transferring the treated aluminum liquid into a crucible, closing a furnace cover of a heat preservation furnace, and putting the heat preservation furnace into a pit;

(7) transferring the pouring sand mold subjected to the V-method quick box burying molding to a pit, and completing butt joint of a liquid lifting pipe and a pouring gate on the sand mold;

(8) sending compressed air into the heat preservation furnace through a compressed air interface, applying pressure to aluminum liquid in the heat preservation furnace to finish pouring operation, and closing the compressed air;

(9) and after the casting is finished, the negative pressure of the vacuum sand box is removed, the dry sand is automatically dispersed, and after the casting is cooled, the 3D printing shell mould on the surface of the casting is removed to obtain the casting blank.

Under the preferable condition, in the step (2), the 3D printer prints out a casting sand mold, the inner mold sand mold adopts a random hollow structure, the outer mold sand mold adopts a random structure, the wall thickness of the sand mold is 30-35mm, and the strength is 5.5-6.0 MPa.

Preferably, in the step (2), the thickness of the sand mold dip coating is 0.5 mm.

Preferably, in the step (2), the sand mold is baked in an oven at 180 ℃ for 4-6 hours.

Under the preferable condition, in the step (8), the pressure applied by the compressed air to the aluminum liquid in the heat preservation furnace is 0.6MPa-1.6 MPa.

Compared with the prior art, the invention has the following technical effects:

the technical concept provided by the invention is that a 3D printing technology is applied to rapidly manufacture a shell mold, a V-method molding mode is adopted to carry out buried box filling, and then a low-pressure process is adopted to carry out pouring; the inventor of the application finds that by flexibly combining a plurality of process technologies, standardized manufacturing process technologies are realized for individualized products with different sizes, different structures and differentiation;

according to the embodiment provided by the invention, the problem that the traditional casting process is difficult to realize the precise casting of complex large-scale metal components and small-batch individualized products is solved, the near-net-shape forming technology is realized, the product quality of castings is greatly improved, the production and manufacturing environment is improved, the labor intensity is reduced, and the green casting can be basically realized; the process technology provided by the invention can enable the product to have more complicated structure, more superior performance, more refined quality, more efficient manufacturing and more reasonable cost performance, and has better application prospect.

Drawings

FIG. 1 shows a schematic representation of a product cast according to example 1 of the present invention;

FIG. 2 illustrates a casting process diagram for the product to be cast in FIG. 1, according to an embodiment of the present invention;

FIG. 3 shows a schematic representation of a 3D printing sand mold drag for the product to be cast in FIG. 1, according to an embodiment of the present invention;

FIG. 4 shows a schematic representation of a 3D printed sand mold cope for the product to be cast of FIG. 1, according to an embodiment of the present invention;

FIG. 5 shows a schematic diagram of a mold close-up of a 3D sand mold according to an embodiment of the present invention;

FIG. 6 shows a schematic casting diagram of the product to be cast of FIG. 1 according to an embodiment of the present invention;

the reference numbers in the figures illustrate: the method comprises the following steps of 1-a vacuum sand box, 2-a vacuum-pumping interface, 3-quartz sand, 4-a PE film, 5-a shell mold, 6-a bottom plate, 7-a pit, 8-a holding furnace, 9-a crucible, 10-a compressed air interface and 11-a liquid lifting pipe.

Detailed Description

In order to make the technical means, the creation features, the achievement purposes and the effects of the invention easy to understand, the invention is further clarified with the specific embodiments.