CN108247053A - A kind of method that 3D printing prepares complex-shaped composite material hot-work die - Google Patents

Abstract

The invention relates to a method for preparing a complex-shaped composite material hot-working mold by 3D printing, and belongs to the technical field of mold preparation. First, mix nano-Ni powder and nano-TiC ceramic powder for ball milling, and then add H3 steel powder for ball milling to obtain a composite material; use drawing software to draw a three-dimensional model of the required space structure, pour H3 steel powder into a 3D printer, and print out a complex shape The mold prototype reserves 20mm unprinted margin at the mold cavity, suspends the printing equipment, replaces the steel powder with Ni powder, and then prints ordinary pure Ni powder on the mold cavity of the mold prototype and is located on the inner surface of the hot work mold steel material. layer; suspend the printing equipment, replace the Ni powder with a composite material and continue printing on the surface of the printed pure Ni layer, clean the formed mold parts, scrape and grind, and polish the mold, and perform fine polishing on the mold to obtain a composite material with complex shapes Hot work mold. The complex-shaped composite material prepared by the invention has uniform hot-working mold structure and good mold performance.

Description

A 3D printing method for preparing hot-working molds for composite materials with complex shapes

technical field

The invention relates to a method for preparing a complex-shaped composite material hot-working mold by 3D printing, and belongs to the technical field of mold preparation.

Background technique

"Modern industry, mold leading" has become the consensus of the manufacturing industry, and the level of the mold industry has become one of the important symbols to measure the level of the country's manufacturing industry. The steel used for the mold that makes hot metal or liquid metal into shape is hot work mold steel. Hot work die steels include hot forging dies, hot extrusion dies and die casting dies. The working condition of the hot work mold is to contact the hot metal to plastically deform the hot solid metal or to die-cast the high-temperature liquid metal. The working conditions of hot work die steel are harsh. In addition to sufficient high temperature hardness and high temperature strength, hot work die steel also needs good high temperature wear resistance and fracture toughness.

With the rapid development of science and technology, the famous British magazine "The Economist" produced a special topic in 2012 and pointed out that the global industry is experiencing the third industrial revolution. And 3D printing technology is regarded as "an important symbol of the third industrial revolution" because it is a cutting-edge and leading emerging technology. At present, there are many methods used in 3D printing rapid prototyping technology on the market. The more mainstream methods include stereolithography SLA, layered solid manufacturing LOM, selective laser sintering SLS, fusion deposition modeling FDM, laser selective melting SLM, etc.

The failure of hot work die steel is mainly due to thermal cracks and thermal fatigue. First, it starts from the surface. Every hot work die will have hot cracks, that is, small network cracks gradually formed on the surface of the die. After a certain number of impacts , the cracks become thicker, so that the surface finish of the casting cannot meet the requirements. At this time, the mold is scrapped, which is a fatigue process of the mold.

How to prepare high-temperature wear-resistant high-temperature mold materials is a problem.

With the development of 3D printing technology in recent years, the mold structure is uniform and high-quality workpieces are obtained. The rapid prototyping technology of laser selective melting metal powder can directly form complete metal parts, which is convenient for manufacturing complex-shaped molds.

Contents of the invention

Aiming at the problems and deficiencies in the above-mentioned prior art, a method for preparing hot-working molds of composite materials with complex shapes by 3D printing is provided. A layer of TiC particle-reinforced steel-based composite material is printed on the inner surface of the mold cavity of the complex composite hot-working mold of the present invention, which has high hardness, high strength, high modulus, high fracture toughness, high temperature wear resistance and high temperature resistance Excellent oxidation performance and comprehensive mechanical properties, and become the most potential high-temperature wear-resistant high-temperature mold material. And because TiC particles act as a strengthening phase in the steel matrix, there is a good interfacial bond between the matrix and the strengthening phase. It is a powerful guarantee that the composite material can give full play to its good mechanical effect. Adhering a layer of nano-sized Ni powder on the surface of the nano-sized TiC powder can change the wetting angle of the two through the high temperature of the laser, improve the wettability between the TiC particles and the steel matrix, and at the same time make the surface layer of the composite material formed more clear. Dense.

A method for 3D printing to prepare a complex-shaped composite material hot-working mold, the specific steps of which are as follows:

Step 1. First mix nano-Ni powder and nano-TiC ceramic powder with a volume ratio of 85-95:5-15 and ball mill for 8-10 hours, and then stand for 10-12 hours to obtain nano-scale TiC ceramic powder with Ni adhered to the surface; The nanoscale TiC ceramic powder adhered to Ni is added with H3 steel powder ball milled for 30-90 minutes according to the volume ratio of 5-15:85-95, and then left to stand for 6-8 hours to obtain a composite material;

Step 2. Use the drawing software to draw the three-dimensional model of the required space structure, and then import it into the layering software for layering. Determine the processing parameters of 3D printing according to the printed hot work die steel material, generate the running track code, and import it into the coaxial feeding point. In the 3D printer, pour H3 steel powder into the 3D printer, print out the prototype of the mold with complex shape, reserve 20mm unprinted margin at the mold cavity, suspend the printing equipment, replace the steel powder with Ni powder, and then replace the ordinary pure Ni Print a layer of powder on the mold cavity of the mold prototype and on the inner surface of the hot work mold steel material, with a layer thickness of 5mm; suspend the printing equipment, replace the Ni powder with the composite material in step 1 and continue printing on the surface of the printed pure Ni layer , the thickness of the layer is 15mm, the formed mold parts are cleaned, scraped and polished, and the mold is finely polished to obtain a complex-shaped composite material hot-working mold.

In the step 1, the nano-Ni powder is 1200 mesh, the nano-TiC ceramic is 1000 mesh, and the H3 steel powder is 600 mesh.

In the step 2, H3 steel powder and Ni powder are both 600 mesh.

The above 3D printing is a 3D laser metal deposition technology.

The beneficial effects of the present invention are:

(1) The complex-shaped composite hot-working mold prepared by the present invention has a relatively large thermal conductivity of 91W/(m·K) due to pure Ni, and has a thermal expansion rate similar to that of H13 steel (Ni: 13.0× 10 ^-6 K ^-1 , H13 steel: 12.2×10 ^-6 K ^-1 ), the larger thermal conductivity can accelerate the cooling of the composite material layer, reduce stress concentration, and the similar thermal expansion coefficient will not make the excessive layer and pure The interface between the H13 steel base and the composite material layer produces stress concentration and cracks.

(2) Due to the inconsistency of heating or cooling rates between the steel base and the ceramic reinforcement on the surface and center of the mold, resulting in volume and small wetting angle and good metallurgical bonding between Ni and steel, it can be made by 3D printing technology The transition layer has a good combination ability with the pure H13 steel base layer and the composite material layer, and the comprehensive performance of the mold will not be reduced due to the addition of the transition layer. At the same time, the laser selective fusion 3D printing technology has simple operation, uniform structure and good mold performance.

Description of drawings

Fig. 1 is a cross-sectional view of a hot-working mold for a complex-shaped composite material prepared by the present invention.

Detailed ways

The present invention will be further described below in combination with the accompanying drawings and specific embodiments.

Example 1

The 3D printing method for preparing a composite hot-working mold with complex shape, the complex composite hot-working mold has a length and width of 760mm and a height of 850mm, and the specific steps are as follows:

Step 1. First mix nano-Ni powder and nano-TiC ceramic powder at a volume ratio of 85:15 and ball mill for 8 hours, then let it stand for 12 hours to obtain nano-sized TiC ceramic powder with Ni attached to the surface; then nano-sized TiC ceramic powder with Ni attached to the surface According to the volume ratio of 15:85, add H3 steel powder and ball mill for 30 minutes, and then stand still for 6 hours to obtain a composite material; the nano-Ni powder is 1200 mesh, the nano-TiC ceramic is 1000 mesh, and the H3 steel powder is 600 mesh;

Step 2. Use proe drawing software to draw the three-dimensional model of the required space structure, and then import it into the magics layering software for layering. Determine the processing parameters of 3D printing according to the printed hot work die steel material, generate the running track code, and import the coaxial Send to the 3D printer, pour H3 steel powder into the 3D printer, print out the mold prototype with complex shape, reserve 20mm unprinted margin at the mold cavity, suspend the printing equipment, replace the steel powder with Ni powder, and then replace the ordinary Print a layer of pure Ni powder on the cavity of the mold prototype and on the inner surface of the hot work die steel material, with a layer thickness of 5mm; suspend the printing equipment, replace the Ni powder with the composite material in step 1 and continue to print on the pure Ni layer Surface printing, the layer thickness is 15mm, the formed mold parts are cleaned, scraped and polished, and the mold is finely polished to obtain a hot-working mold with complex shapes; the H3 steel powder and Ni powder are both 600 mesh; The above 3D printing is a 3D laser metal deposition technology.

Figure 1 shows the cross-sectional view of the hot-working mold for complex composite materials prepared in this example. It can be seen from Figure 1 that it is difficult to realize such a metal die-casting mold by traditional processing methods, and it is difficult to ensure the thickness of the Ni layer and the composite material layer. Uniform. The complex-shaped composite material prepared in this example has a high surface hardness and a microhardness of 860HV. The fatigue life at 650°C is twice that of the original H13 hot-pressing mold, and the microhardness is increased by 30-45%. Sexuality increased by 50%.

Example 2

The 3D printing method for preparing a hot-working mold of a complex composite material, the hot-working mold of a complex composite material is a B-pillar of an automobile, and the specific steps are as follows:

Step 1. First mix nano-Ni powder and nano-TiC ceramic powder with a volume ratio of 90:10 and ball mill for 10 hours, then let it stand for 10 hours to obtain nano-sized TiC ceramic powder with Ni attached to the surface; then nano-sized TiC ceramic powder with Ni attached to the surface According to the volume ratio of 10:90, add H3 steel powder and ball mill for 90 minutes, and then stand still for 8 hours to obtain a composite material; the nano-Ni powder is 1200 mesh, the nano-TiC ceramic is 1000 mesh, and the H3 steel powder is 600 mesh;

Step 2. Use proe drawing software to draw the three-dimensional model of the required space structure, and then import it into the magics layering software for layering. Determine the processing parameters of 3D printing according to the printed hot work die steel material, generate the running track code, and import the coaxial Send to the 3D printer, pour H3 steel powder into the 3D printer, print out the mold prototype with complex shape, reserve 20mm unprinted margin at the mold cavity, suspend the printing equipment, replace the steel powder with Ni powder, and then replace the ordinary Print a layer of pure Ni powder on the cavity of the mold prototype and on the inner surface of the hot work die steel material, with a layer thickness of 5mm; suspend the printing equipment, replace the Ni powder with the composite material in step 1 and continue to print on the pure Ni layer Surface printing, the layer thickness is 15mm, the formed mold parts are cleaned, scraped and polished, and the mold is finely polished to obtain a hot-working mold with complex shapes; the H3 steel powder and Ni powder are both 600 mesh; The above 3D printing is a 3D laser metal deposition technology.

The complex-shaped composite hot-working die prepared in this example adopts the high-temperature stamping die prepared in this example to have a high surface hardness, the microhardness reaches 830HV, and the high-temperature fatigue life is 4 times that of the original H13 high-temperature stamping die. The microhardness is increased by 30-40%, and the wear resistance is increased by 40%.

Example 3

The 3D printing method for preparing a complex-shaped composite material hot-working mold, the specific steps are as follows:

Step 1. First mix nano-Ni powder and nano-TiC ceramic powder at a volume ratio of 95:5 and ball mill for 9 hours, then let it stand for 11 hours to obtain nano-sized TiC ceramic powder with Ni attached to the surface; then nano-sized TiC ceramic powder with Ni attached to the surface According to the volume ratio of 5:95, add H3 steel powder and ball mill for 60 minutes, and then stand still for 7 hours to obtain a composite material; the nano-Ni powder is 1200 mesh, the nano-TiC ceramic is 1000 mesh, and the H3 steel powder is 600 mesh;

Step 2. Use proe drawing software to draw the three-dimensional model of the required space structure, and then import it into the magics layering software for layering. Determine the processing parameters of 3D printing according to the printed hot work die steel material, generate the running track code, and import the coaxial Send to the 3D printer, pour H3 steel powder into the 3D printer, print out the mold prototype with complex shape, reserve 20mm unprinted margin at the mold cavity, suspend the printing equipment, replace the steel powder with Ni powder, and then replace the ordinary Print a layer of pure Ni powder on the cavity of the mold prototype and on the inner surface of the hot work die steel material, with a layer thickness of 5mm; suspend the printing equipment, replace the Ni powder with the composite material in step 1 and continue to print on the pure Ni layer Surface printing, the layer thickness is 15mm, the formed mold parts are cleaned, scraped and polished, and the mold is finely polished to obtain a hot-working mold with complex shapes; the H3 steel powder and Ni powder are both 600 mesh; The above 3D printing is a 3D laser metal deposition technology.

The specific embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Variations.

Claims (3)

1. A method for 3D printing to prepare complex-shaped composite material thermal work molds, characterized in that the specific steps are as follows: Step 1. First mix nano-Ni powder and nano-TiC ceramic powder with a volume ratio of 85-95:5-15 and ball mill for 8-10 hours, and then stand for 10-12 hours to obtain nano-scale TiC ceramic powder with Ni adhered to the surface; The nanoscale TiC ceramic powder adhered to Ni is added with H3 steel powder ball milled for 30-90 minutes according to the volume ratio of 5-15:85-95, and then left to stand for 6-8 hours to obtain a composite material; Step 2. Use the drawing software to draw the three-dimensional model of the required space structure, and then import it into the layering software for layering. Determine the processing parameters of 3D printing according to the printed hot work die steel material, generate the running track code, and import it into the coaxial feeding point. In the 3D printer, pour H3 steel powder into the 3D printer, print out the prototype of the mold with complex shape, reserve 20mm unprinted margin at the mold cavity, suspend the printing equipment, replace the steel powder with Ni powder, and then replace the ordinary pure Ni Print a layer of powder on the mold cavity of the mold prototype and on the inner surface of the hot work mold steel material, with a layer thickness of 5mm; suspend the printing equipment, replace the Ni powder with the composite material in step 1 and continue printing on the surface of the printed pure Ni layer , the thickness of the layer is 15mm, the formed mold parts are cleaned, scraped and polished, and the mold is finely polished to obtain a complex-shaped composite material hot-working mold. 2. The method for preparing complex-shaped composite material hot-working molds by 3D printing according to claim 1, characterized in that: in the step 1, the nano-Ni powder is 1200 mesh, the nano-TiC ceramic is 1000 mesh, and the H3 steel powder is 600 mesh . 3. The method for preparing hot-working molds for composite materials with complex shapes by 3D printing according to claim 1, characterized in that: in the step 2, both H3 steel powder and Ni powder are 600 mesh.