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CN-121976094-A - Laser directional energy deposition 3D printing crack-free high-carbon Co-Cr alloy and manufacturing method thereof

CN121976094ACN 121976094 ACN121976094 ACN 121976094ACN-121976094-A

Abstract

The invention belongs to the technical field of additive manufacturing, and discloses a laser directional energy deposition 3D printing crack-free high-carbon Co-Cr alloy and a manufacturing method thereof. The method comprises the steps of mixing high-carbon Co-Cr alloy powder with Mn powder raw materials to prepare mixed powder, wherein the mass of the Mn powder raw materials is 1.0% -8.0% of the mass of the mixed powder, and the step of laser directional energy deposition to prepare the crack-free high-carbon Co-Cr alloy member. According to the invention, through optimizing components and technological parameters, a bimodal microstructure of micron-sized fine crystals and larger-sized columnar crystals is formed in the 3D printed high-carbon Co-Cr alloy, and the bimodal microstructure can inhibit stress concentration and crack propagation of the high-carbon Co-Cr alloy, so that the problem of easiness in cracking during molding of the high-carbon Co-Cr alloy LDED is effectively solved.

Inventors

  • LIU JINLONG
  • LI SONGCHANG
  • WU SHUQUAN

Assignees

  • 东北大学

Dates

Publication Date
20260505
Application Date
20260209

Claims (9)

  1. 1. A manufacturing method of a crack-free high-carbon Co-Cr alloy for laser directional energy deposition 3D printing is characterized in that high-carbon Co-Cr alloy powder and Mn powder raw materials are subjected to 3D printing through laser directional energy deposition to obtain a crack-free high-carbon Co-Cr alloy component.
  2. 2. The method for manufacturing a laser directed energy deposition 3D printing crack-free high carbon Co-Cr alloy according to claim 1, comprising the steps of: The method comprises the steps of mixing high-carbon Co-Cr alloy powder with Mn powder raw materials to prepare mixed powder, wherein the mass of the Mn powder raw materials is 1.0% -8.0% of the mass of the mixed powder; And secondly, carrying out laser directional energy deposition to obtain the crack-free high-carbon Co-Cr alloy component.
  3. 3. The method for manufacturing a 3D printing crack-free high-carbon Co-Cr alloy by laser directional energy deposition according to claim 1 or 2, wherein the mass of the Mn powder raw material is 3.0% -6.0% of the mass of the mixed powder.
  4. 4. The method for producing a crack-free high-carbon Co-Cr alloy for laser directional energy deposition 3D printing according to claim 3, wherein the particle size of the high-carbon Co-Cr alloy powder is 53 μm to 105. Mu.m, and the particle size of the Mn powder raw material is 53 μm to 105. Mu.m.
  5. 5. The method for manufacturing the laser directional energy deposition 3D printing crack-free high-carbon Co-Cr alloy is characterized in that high-carbon Co-Cr alloy powder and Mn powder raw materials are mixed and then subjected to ball milling and drying, wherein ball milling parameters are 316L of ball milling steel ball materials, the ball milling rotating speed is 150 r/min-250 r/min, the ball milling time is 3-5 h, and drying parameters are 60-120 ℃ and 2 h.
  6. 6. The method for manufacturing the crack-free high-carbon Co-Cr alloy for laser directional energy deposition 3D printing, according to claim 5, is characterized in that the high-carbon Co-Cr alloy powder comprises, by mass, 20.0% -23.0% of Cr, 3.5% -5.5% of W, 1.6% -1.8% of C, 0.05% -2.0% of Mo, 0.05% -3.0% of Ni, 0.05% -3.0% of Fe, the balance Co and unavoidable impurities, and the purity of Mn powder raw materials exceeds 99.9%.
  7. 7. The method for manufacturing the crack-free high-carbon Co-Cr alloy for laser directional energy deposition 3D printing of claim 6, wherein the laser directional energy deposition parameters are laser power 1.0 kW-1.5 kW, circular light spot diameter 2 mm-4 mm, overlap ratio 40% -60%, scanning speed 8 mm/s-12 mm/s, powder feeding amount 8 g/min-12 g/min and powder feeding argon flow 7L/min-9L/min.
  8. 8. The method for manufacturing a 3D printing crack-free high-carbon Co-Cr alloy by laser directional energy deposition according to claim 7, wherein the crack-free high-carbon Co-Cr alloy member has a bimodal structure, the grain size of the microstructure shows a 'double peak' grain size distribution formed by alternately distributing fine grain regions and coarse grain regions, the fine grain regions are small-size equiaxed grains with a size of 5 μm to 15 μm, the coarse grain regions are large columnar dendrites, and the equivalent wafer diameter size is 40 μm to 150 μm.
  9. 9. The crack-free high-carbon Co-Cr alloy prepared by the manufacturing method according to any one of claims 1 to 8, wherein the crack-free high-carbon Co-Cr alloy has a room temperature compression strength of 2438 MPa~2965 MPa, a yield strength of 985 MPa to 1017 MPa and an elongation of 16% -26%.

Description

Laser directional energy deposition 3D printing crack-free high-carbon Co-Cr alloy and manufacturing method thereof Technical Field The invention relates to the technical field of additive manufacturing, in particular to a laser directional energy deposition 3D printing crack-free high-carbon Co-Cr alloy and a manufacturing method thereof. Background Laser Directed Energy Deposition (LDED) 3D printing using powder as a raw material is a widely used metal additive manufacturing technology, and the principle of the technology is that laser focusing forms a high energy region, and metal powder conveyed synchronously is melted to realize layer-by-layer deposition. The technology has the advantages of stable heat input, higher molding precision, high energy and material utilization rate and the like. The method has remarkable value in repairing high-precision parts such as aero-engine blades and the like and preparing the wear-resistant coating, and provides an effective path for manufacturing, upgrading and prolonging the service life of parts. Co-Cr alloy has wide application in easily worn workpieces due to high temperature resistance and abrasion resistance. The Co-Cr alloy is divided into low carbon type (< 0.25 wt%) and high carbon type (0.25 wt% C2.5 wt%) according to carbon content. The low-carbon Co-Cr alloy has excellent toughness, and the LDED printed forming property is good by taking the low-carbon Co-Cr alloy powder as a raw material, so that cracks are not easy to generate, but the wear resistance is poor. In contrast, high carbon Co-Cr alloys have outstanding hardness and wear resistance due to the large number of carbide particles inside, but LDED are prone to cracking when printed. With respect to high carbon Co-Cr alloy 3D printing studies, currently attempted printing methods include plasma arc directed energy deposition and arc directed energy deposition techniques in addition to LDED. Patent CN 115433934B adds Ti 3SiC2 powder to high carbon Co-Cr alloy, and uses LDED technique to prepare directional energy deposition layer with excellent wear resistance and oxidation resistance, but the thickness of directional energy deposition layer is smaller, lower than 1.5 mm. The patent CN 117966151A discloses a process method for printing high-carbon Co-Cr alloy by plasma arc directional energy deposition, which preheats a substrate and deposits an intermediate layer first, so that a high-carbon Co-Cr alloy deposition layer without micro cracks can be prepared. Patent CN 115592250A discloses a plasma arc directional energy deposition printing high-carbon Co-Cr alloy doped with tungsten carbide/titanium carbide, which meets the requirement of wear resistance in the service process. The plasma directional energy deposition and arc directional energy deposition technology has the characteristics of large heat input, relatively slow cooling and difficult crack generation when printing high-carbon Co-Cr alloy, but has the problems of large molten pool, easy element burning loss, low forming precision and the like during deposition. Although LDED technology has outstanding advantages in printing high-carbon Co-Cr alloy, the printing high-carbon Co-Cr alloy still has extremely strong hot cracking tendency, on one hand, the reason is that the service life of a molten pool for laser directional energy deposition is extremely short, the residual stress generated in the deposition process is large, crack initiation and crack expansion are easy to occur, and on the other hand, the toughness of the high-carbon Co-Cr alloy is poor. In conclusion, when the high-carbon Co-Cr alloy is prepared by adopting different additive manufacturing methods, the common problem of insufficient toughness of the alloy is generally faced, wherein when printing is carried out by adopting a LDED process, the printing cracking defect which is difficult to avoid is more easily caused by the traditional component formula. Therefore, the development of the novel crack-free high-carbon Co-Cr-based alloy and the printing technology thereof, which are suitable for LDED processes, has important commercial value and wide application prospect. Disclosure of Invention The invention aims to provide a manufacturing method of a laser directional energy deposition 3D printing crack-free high-carbon Co-Cr alloy, which has the advantages of simple preparation process, capability of obviously improving the performance of LDED deposition layers and improvement of the cracking problem of the deposition layers. In order to achieve the purpose, the invention provides the following technical scheme that the manufacturing method of the crack-free high-carbon Co-Cr alloy for laser directional energy deposition 3D printing comprises the steps of carrying out 3D printing on high-carbon Co-Cr alloy powder and Mn powder raw materials through laser directional energy deposition to obtain a crack-free high-carbon Co-Cr alloy component. The method comprises the foll