Method for preparing Mg-RE alloys with high strength and ductility using selective laser melting additive manufacturing technology

Patent metadata

Field	Value
Publication number	US-12202040-B2
Application number	US-202017769325-A
Country	US
Kind code	B2
Filing date	Sep 27, 2020
Priority date	Oct 15, 2019
Publication date	Jan 21, 2025
Grant date	Jan 21, 2025

Abstract

A method for preparing Mg-RE alloys with high strength and ductility using selective laser melting (SLM) additive manufacturing technology includes the following steps of: A. preparing Mg-RE-(Zn)—Zr pre-alloyed spherical powder by gas atomization; B. molding the Mg-RE-(Zn)—Zr pre-alloyed spherical powder using SLM to obtain the Mg-RE alloys with high strength and ductility; and C. conducting heat treatment on the Mg-RE alloys prepared in step B: solid solution+aging treatment or only aging treatment The method adjusts and controls microstructure and mechanical properties of the alloys by adjusting and controlling process parameters of SLM (laser power, scanning speed, hatch spacing, spot diameter, layer thickness, interlayer rotation angle, substrate preheating temperature, partition width and overlapping area width) and process parameters of subsequent heat treatment (temperature and time) to prepare the Mg-RE-(Zn)—Zr alloys with high strength and ductility using SLM process for the first time.

First claim

What is claimed is:

1. A method for preparing magnesium gadolinium (Mg—Gd) alloys using selective laser melting (SLM) additive manufacturing technology, comprising the following steps:
step A: preparing Mg—Gd—(Zn)—Zr pre-alloyed spherical powder by gas atomization;
step B: molding the Mg—Gd—(Zn)—Zr pre-alloyed spherical powder using SLM to obtain the Mg—Gd alloys; and
step C: conducting heat treatment on the Mg—Gd alloys prepared in step B: solid solution heat treatment with aging treatment or only aging treatment;
wherein in step A, the Mg—Gd—(Zn)—Zr pre-alloyed spherical powder contains the following elements in weight percentages: Gd 10-20%, Zn 0-2%, Zr 0-0.5%, with a balance being Mg and unavoidable impurities, wherein a total amount of the unavoidable impurities is less than 0.02%; and
wherein in step B, related laser parameters adopted in the SLM molding are as follows: a laser power of 80-160 W, a scanning speed of 100-1000 mm/s, a hatch spacing of 50-100 μm, and a spot diameter of 65-150 μm.

2. The method according to claim 1 , wherein in step B, the Mg—Gd—(Zn)—Zr pre-alloyed spherical powder is powder screened with more than 200 mesh.

3. The method according to claim 1 , wherein in step B, the Mg—Gd—(Zn)—Zr pre-alloyed spherical powder is dried at 100-200° C. for 1-5 h before the SLM molding.

4. The method according to claim 1 , wherein in step B, a laser scanning strategy adopted in the SLM molding is a partition island scanning strategy, with a partition width of 3-6 mm, an overlapping area width of 0.1-0.3 mm between partitions, and an interlayer rotation angle of 70-75°.

5. The method according to claim 1 , wherein in step B, other process parameters adopted in the SLM molding are as follows: a layer thickness of 20-40 μm, and a substrate preheating temperature of 25-200° C.

6. The method according to claim 1 , wherein in step B, the SLM molding is carried out under a protection of argon gas, and oxygen and water vapor in a molding cabin are lower than 100 ppm during the SLM molding.

7. The method according to claim 1 , wherein in step C, the solid solution heat treatment is conducted at 450-520° C. for 15 min-2 h.

8. The method according to claim 1 , wherein in step C, the aging treatment is conducted at 175-225° C. for 0-512 h.

Assignees

• Univ Shanghai Jiaotong

Inventors

• Wu Yujuan
• Deng Qingchen
• Peng Liming
• Luo Yuanhang
• Su Ning
• Chang Zhiyu
• Xue Xiaoyu

Classifications

• C22C1/0408

  Light metal alloys · CPC title

• B22F2301/058

  Magnesium · CPC title

• B22F9/082 Primary

  atomising using a fluid (using centrifugal force B22F9/10) · CPC title

• B33Y80/00

  Products made by additive manufacturing · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title