Method for improving density and component uniformity of selected area laser melting product

A selective laser melting and densification technology, which is applied in the directions of improving energy efficiency, process efficiency, and additive processing, etc., can solve the problems of uneven distribution of components, obstacles to the development of laser in-situ synthesis technology, and low densities. Promotes uniform spreading, generation suppression, and defect suppression effects

Inactive Publication Date: 2020-10-13
TIANJIN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the development of laser in situ synthesis technology has been hindered by a series of obstacles.
The main problem is the uneven distribution of components after in sit

Method used

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  • Method for improving density and component uniformity of selected area laser melting product
  • Method for improving density and component uniformity of selected area laser melting product

Examples

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Comparison scheme
Effect test

Embodiment 1

[0028] A method for improving the density and composition uniformity of selected laser melting products, including the following steps:

[0029] Step 1, raw materials are mixed, the mixed powder is in accordance with FeCoCrNiSi 0.05 The atomic ratio is configured to mix in a three-dimensional mixer for 3 hours, the cylinder speed is 30r / min, and the uniformly mixed powder is dried in a vacuum dryer for 8 hours at a temperature of 80 degrees Celsius, and the vacuum is less than 10KPa absolute pressure. After completion, sealed and preserved to obtain high-entropy alloy powder.

[0030] Step 2. Additive preparation. The substrate is made of 316L stainless steel with a size of 250×250×15mm. The surface of the substrate is polished with an angle grinder until there is no oxide. The oil and dirt on the surface are cleaned with acetone and alcohol respectively. Put the high-entropy alloy powder obtained after the completion of the step 1 into the printer silo, and use the AM-400 laser 3D...

Embodiment 2

[0040] A method to improve the density and composition uniformity of laser melting products in selected areas:

[0041] Printing of FeCoCrNiMn alloy powder based on SLM technology. Since the alloy powder has undergone repeated component blending in the powdering process, there is no obvious segregation in the component distribution, and the method of the invention can improve its density.

[0042] For additive preparation, the substrate is made of 316L stainless steel with a size of 250×250×15mm. The surface of the substrate is polished with an angle grinder until there is no oxide. The oil and dirt on the surface are cleaned with acetone and alcohol respectively, and the FeCoCrNiMn alloy The powder is put into the printer silo, the AM-400 laser 3D printing equipment produced by Renishaw is used for laser additive manufacturing, and a block with a size of 6mm×6mm×6mm is constructed in Renishaw-QuantAM, and the rotation angle between layers is set It is 67° to release the residual ...

Embodiment 3

[0047] A method for improving the density and composition uniformity of selected laser melting products, including the following steps:

[0048] Printing of FeCoCrNi alloy powder based on SLM technology. Since the alloy powder has undergone repeated component blending in the powdering process, there is no obvious segregation in the component distribution, and the method of the invention can improve its density.

[0049] For additive preparation, the substrate is made of 316L stainless steel with a size of 250×250×15mm. The surface of the substrate is polished with an angle grinder until there is no oxide. The oil and dirt on the surface are cleaned with acetone and alcohol respectively, and the FeCoCrNi alloy The powder is put into the printer silo, and the AM-400 laser 3D printing equipment produced by Renishaw is used for laser additive manufacturing, and a block with a size of 6mm×6mm×6mm is constructed in Renishaw-QuantAM, and the rotation angle between layers is set It is 67°...

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Abstract

The invention discloses a method for improving density and component uniformity of a selected area laser melting product. The method is characterized in that in a laser printing process, two scans arecarried out after each layer of powder is laid, the second scan is carried out immediately after the first scan, and the power of the second scan is 50-60% of that of the first print scan; and the line point distance of the second scan is 1.4-2.4 times that of the first scan. The density of each layer after two scans is obviously improved compared with that of a conventional single scan sample. Due to the fact that the second scan provides an opportunity for defect closure, in the second scan, some defects remaining after the first scan are eliminated. In addition, most defects are caused bypoor spreading of the powder. The surface roughness is decreased significantly after the second scan so as to promote the uniform spreading of the powder to some extent, and therefore an inhibiting effect is achieved on generation of defects.

Description

Technical field [0001] The invention belongs to the technical field of laser additive manufacturing, and specifically relates to a method for improving the density and composition uniformity of selected laser melting products. Background technique [0002] High-entropy alloys have been extensively studied in the material industry in recent years due to their excellent mechanical properties and corrosion resistance. However, the high-entropy alloy system is huge, and its specific formation mechanism and strengthening mechanism have not yet been fully clarified. It still needs a considerable period of research and exploration. [0003] The method of preparing high-entropy alloy samples is mainly vacuum arc casting, but this method can prepare samples with simple geometry and cannot prepare samples with complex shapes. Compared with vacuum arc casting, in recent years, laser additive manufacturing has become a research focus in the material industry because of its strong adaptability...

Claims

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Application Information

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IPC IPC(8): B22F3/105B33Y10/00B33Y50/02
CPCB33Y10/00B33Y50/02Y02P10/25
Inventor 徐连勇林丹阳荆洪阳韩永典吕小青赵雷
Owner TIANJIN UNIV
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