Weldable in-situ nano-strengthened rare-earth metal containing aluminum alloy with high strength and toughness and preparation method thereof

Patent metadata

Field	Value
Publication number	US-12173385-B2
Application number	US-202118287187-A
Country	US
Kind code	B2
Filing date	Jun 3, 2021
Priority date	May 27, 2021
Publication date	Dec 24, 2024
Grant date	Dec 24, 2024

Abstract

The present disclosure relates to an aluminum alloy material, and specifically to a weldable in-situ nano-strengthened rare-earth metal (REM)-containing aluminum alloy with high strength and toughness and a preparation method thereof. In the present disclosure, in-situ nano-ceramic particles and REMs simultaneously introduced into an Al—Zn—Mg alloy can effectively refine the grains and significantly improve the strength and toughness of the alloy; and REM-containing nano-precipitated phases and in-situ nanoparticles distributed in the grains or at grain boundaries can also significantly increase a recrystallization temperature of the alloy, effectively inhibit the dynamic recovery, reduce the re-dissolution of alloying elements, and improve the weldability of the alloy.

First claim

What is claimed is:

1. A preparation method of a weldable in-situ nano-strengthened rare-earth metal-containing aluminum alloy, the weldable in-situ nano-strengthened rare-earth metal-containing aluminum alloy comprising the following chemical components in mass percentages: Zn: 5 to 7, Mg: 2 to 3, Mn: 0.7 to 0.8, Cr: 0.1 to 0.2, Cu: 0.2 to 0.3, Zr: 1.5 to 8, Ti: 1.5 to 8, B: 0.4 to 5, O: 0.2 to 2, Er: 0.05 to 0.3, Sc: 0.05 to 0.3, Y: 0.1 to 0.5, and Al: the balance, wherein the weldable in-situ nano-strengthened rare-earth metal-containing aluminum alloy is prepared through composition control, in-situ nano-ceramic particle strengthening and refinement, rare-earth metal microalloying, acoustic magnetic field-controlled compounding, and ultrasonic semi-continuous casting based on an Al—Zn—Mg aluminum alloy as a matrix, to obtain the weldable in-situ nano-strengthened rare-earth metal-containing aluminum alloy comprising nano-Al 3 (Er+Zr) rare-earth metal-containing precipitated phase, nano-Al 3 (Sc+Zr) rare-earth metal-containing precipitated phase, and nano-Al 3 Y rare-earth metal-containing precipitated phase uniformly distributed in grains and a large number of in-situ nano-ZrB 2 ceramic particles, in-situ nano-Al 2 O 3 ceramic particles, and in-situ nano-TiB 2 ceramic particles distributed at grain boundaries; and the preparation method comprises the following specific steps:
(1) performing an in-situ reaction for in-situ generating the nano-ceramic particles under a control of an acoustic magnetic field;
(2) after the in-situ reaction is completed, introducing metal elements and rare-earth metals as follows: after the in-situ reaction is completed, cooling to 750° C. to 760° C., adding pure Zn, pure Cu, Al—Cr, Al—Mn, Al—Zr, and rare-earth metal-containing intermediate alloys, and conducting a reaction for 10 min to 15 min; after the reaction is completed, conducting slagging-off, refining, and degassing; and cooling to 680° C., adding pure Mg, and further conducting a reaction for 10 min to 15 min, wherein the rare-earth metals are Sc, Er, and Y;
(3) preparing an aluminum alloy ingot with uniform components, and a controllable distribution of the nano-ceramic particles in the grains or at the grain boundaries through the ultrasonic semi-continuous casting; and
(4) finally, subjecting the aluminum alloy ingot to homogenization, forming, and a heat treatment to obtain the weldable in-situ nano-strengthened rare-earth metal-containing aluminum alloy.

2. The preparation method of the weldable in-situ nano-strengthened rare-earth metal-containing aluminum alloy according to claim 1 , wherein in the step (1), reactants for generating the nano-ceramic particles are two or more selected from the group consisting of K 2 ZrF 6 , K 2 TiF 6 , KBF 4 , Na 2 B 4 O 7 , ZrO 2 , B 2 O 3 , and Al 2 (SO 4 ) 3 ; the nano-ceramic particles are nano-ZrB 2 ceramic particles, nano-Al 2 O 3 ceramic particles, and nano-TiB 2 ceramic particles generated through the in-situ reaction in a melt and have a particle size of 10 nm to 100 nm, and a volume fraction of 1% to 15% based on the weldable in-situ nano-strengthened rare-earth metal-containing aluminum alloy; and the control of the acoustic magnetic field is conducted under the following parameters: a pulse width range: 100 μs to 50 ms, a frequency range: 10 Hz to 15 Hz, a pulse magnetic field peak intensity range: 1 T to 10 T, an ultrasonic power: 5 kW to 10 kW, an ultrasonic time: 10 min, and an ultrasonic interval: 2 minutes.

3. The preparation method of the weldable in-situ nano-strengthened rare-earth metal-containing aluminum alloy according to claim 1 , wherein in the step (3), the ultrasonic semi-continuous casting is conducted under the following conditions: an ultrasonic output frequency: 25±0.5 kHz, an ultrasonic output power: 200 W to 300 W, and an ultrasonic treatment mode: continuous ultrasound.

4. The preparation method of the weldable in-situ nano-strengthened rare-earth metal-containing aluminum alloy according to claim 1 , wherein in the step (4), the homogenization is conducted by a secondary homogenization process: 350° C. to 370° C./8 h to 10 h+450° C. to 470° C./10 h to 12 h; the forming is conducted by one or more selected from the group consisting of rolling, extrusion, and forging, annealing is conducted at 500° C. for 4 h before the forming, and the forming is conducted at 450° C. to 500° C. with a deformation amount of 50% to 500%; and the heat treatment is conducted as follows: T6: 470° C. to 500° C./1 h to 2 h, water-cooling+150° C. to 160° C./30 min to 12 h.

Assignees

• Univ Jiangsu

Inventors

• Kai Xizhou
• Zhao Yutao
• Peng Yanjie
• Chen Gang
• Chen Ruikun
• Wu Lin
• Tao Ran
• Liang Xiangfeng

Classifications

• C22F1/053

  of alloys with zinc as the next major constituent · CPC title

• C22F1/002

  by rapid cooling or quenching; cooling agents used therefor · CPC title

• C22C21/10 Primary

  with zinc as the next major constituent · CPC title

• C22C21/003

  containing at least 2.6% of one or more of the elements: tin, lead, antimony, bismuth, cadmium, and titanium · CPC title

• B22D11/114

  by using agitating or vibrating means (B22D11/117 takes precedence) · CPC title