CN-122007548-A - 2XXX series aluminum alloy member arc additive manufacturing and heat treatment integrated method

CN122007548ACN 122007548 ACN122007548 ACN 122007548ACN-122007548-A

Abstract

The invention provides an integrated method for arc additive manufacturing and heat treatment of a 2XXX aluminum alloy member. The method is characterized in that stable interlayer metallurgical bonding and lower heat accumulation of the 2XXX series aluminum alloy component are obtained in a forming stage by carrying out cooperative regulation and control on an arc additive manufacturing deposition process, interlayer heat history and a subsequent heat treatment system, dendrite segregation is weakened, netlike second phase dissolution, pores and local tissue non-uniformity are reduced by a flow design of homogenizing annealing, solid solution treatment and aging treatment in a post treatment stage, and a reinforced precipitated phase with fine dispersion distribution is formed in an aging process, so that the uniformity of strength, plasticity and overall performance of the 2XXX series aluminum alloy component manufactured by arc additive manufacturing is effectively improved.

Inventors

JIANG BOTAO
Yan Boheng
YU NAN
CAI MIN
SU BAOXIAN
LIU CHEN
WANG LIANG
SU YANQING

Assignees

哈尔滨工业大学

Dates

Publication Date: 20260512
Application Date: 20260401

Claims (10)

1. An integrated 2XXX series aluminum alloy member arc additive manufacturing and heat treatment method, the method comprising: Selecting matched single wire welding materials or combined wire feeding welding materials according to the component range of the target 2XXX aluminum alloy, and carrying out deoiling, dehumidifying and deoxidizing film treatment on the welding wires and the base plate; step two, low heat input arc additive deposition, namely adopting a low heat input arc additive manufacturing mode to carry out layer-by-layer and channel-by-channel deposition, controlling the lap joint rate of a welding bead, the interlayer temperature, the interlayer residence time and the alternation of start and stop positions, enabling a deposition layer to form continuous formation without burning and sinking, and reducing heat accumulation; homogenizing the deposited component to promote the redistribution of the in-layer/interlayer segregation solute, weaken the influence of the continuous network second phase and the residual eutectic, and cool rapidly after homogenization; Fourthly, carrying out solution treatment on the homogenized component, and quenching the component to enable second phases originally distributed along grain boundaries, dendrite intervals and interlayer regions in the component to be dissolved back into an alpha-Al matrix to form supersaturated solid solution; And fifthly, aging treatment, namely selecting single-stage aging or double-stage aging according to the precipitation response of a target mark, and promoting precipitation of a fine dispersion strengthening phase by controlling aging temperature and heat preservation time to obtain the 2XXX series aluminum alloy component with high strength and high uniformity.
2. The method of claim 1, wherein the material pretreatment process in step one comprises the steps of carrying out surface state inspection and cleaning treatment on the welding wire before use, keeping the surface of the welding wire dry, continuous and flat, avoiding the adhesion of greasy dirt, lubrication residue, dust and hydrated oxide film formed by wetting, preserving the unsealed welding wire in a dry and clean environment, wiping the surface of the welding wire by dipping volatile degreasing agent with non-woven fabrics or clean soft cloth before use to remove organic pollutants, and increasing the surface cleaning strength for the welding wire with obvious surface oxidation or relatively long storage time, thereby avoiding the adoption of a treatment mode which can significantly damage the surface integrity of the welding wire or introduce secondary pollution.
3. The method of claim 1, wherein the low heat input arc additive manufacturing method in the second step is CMT, cmt+ P, CMT-PADV, pulse MIG or pulse GMAW, the welding bead lap ratio is 20% -60%, the interlayer temperature is 60% -180 ℃, and the interlayer residence time is 10-90 s.
4. The method of claim 1, wherein one or more of reciprocating scanning, alternate scanning and zone deposition are adopted in the low heat input arc additive manufacturing process, wherein adjacent deposition layers adopt reverse reciprocating scanning to enable the starting end and the ending end of the adjacent layers to alternate, for a single-layer section formed by a plurality of deposition channels, adjacent welding passes adopt any one of left-right alternation, middle-to-two alternation, two-side alternation, odd-even channel alternation or symmetrical channel alternation for carrying out channel arrangement, and when the length, width or local thickness of a component to be prepared is relatively large, the deposition area is divided into two or more relatively independent deposition sections and the zone deposition is carried out in a preset sequence.
5. The method according to claim 1, wherein the homogenization treatment temperature in the third step is 485-515 ℃, the heat preservation time is 6-16 h, and the homogenization treatment temperature is 10-35 ℃ lower than the subsequent solution treatment temperature.
6. The method according to claim 1, wherein the homogenization treatment and the solution treatment are performed in an air circulation furnace, an inert atmosphere furnace or a vacuum furnace, wherein when the inert atmosphere furnace is adopted, the inert atmosphere is argon, nitrogen or a mixture thereof, a water cooling or forced air cooling rapid cooling mode is adopted after the homogenization treatment is finished, and a rapid quenching mode is adopted after the solution treatment.
7. The method according to claim 1, wherein the temperature of the solution treatment in the fourth step is 520-545 ℃ and the holding time is 1-5 h, and the temperature of the solution treatment is determined by the initial melting temperature of the target alloy or the deposited structure and is set to be 5-20 ℃ below the initial melting temperature.
8. The method according to claim 1, wherein in the fifth step, single-stage aging is used for a member whose deposited state structure is relatively uniform, whose segregation and directional property difference is relatively small and whose main object is to simplify the process flow, and double-stage aging is used for a member whose deposited state has a significant intra-layer/inter-layer structure difference, whose thickness direction or height direction property fluctuation is relatively large, or for a member whose high strength, high plasticity and high uniformity are simultaneously required.
9. The method of claim 8, wherein the single-stage aging treatment is performed at 160-190 ℃ for 6-20 hours, and the double-stage aging treatment comprises a pre-aging treatment of 100-130 ℃ and 6-24 hours in a first stage and a strengthening aging treatment of 160-190 ℃ and 6-20 hours in a second stage.
10. The method of claim 9, wherein the dual stage aging treatment is performed without a protective atmosphere, wherein the air cooling is performed to room temperature after the first aging is completed, the temperature is raised to a second aging temperature and maintained, and the air cooling is performed to room temperature after the second aging is completed.

Description

2XXX series aluminum alloy member arc additive manufacturing and heat treatment integrated method Technical Field The invention relates to the technical field of aluminum alloy additive manufacturing and forming and post-treatment thereof, in particular to an electric arc additive manufacturing and heat treatment integrated method for a 2XXX aluminum alloy member. In particular to an integrated method for arc additive manufacturing and heat treatment of an aluminum alloy component, and particularly relates to a preparation method for realizing high strength and high uniformity of the component through low heat input layer-by-layer deposition, interlayer heat history control and homogenization-solid solution-aging cooperative treatment. Background The 2XXX aluminum alloy belongs to a typical Al-Cu heat-treatable reinforced aluminum alloy, has higher specific strength, good welding suitability and better low-temperature service performance in part of brands, and has long-term importance in aerospace storage tanks, rib plates, frame beams, skin reinforcements and other lightweight bearing components. Particularly, the brands 2219 and 2319 are often regarded as important candidate materials of a large-scale aluminum alloy welding/additive structure because of clear Cu main strengthening mechanism and relatively rich experience of traditional welding engineering. Compared with the traditional plate machining or forging machining, the arc fuse additive manufacturing (WAAM) has the advantages of high deposition efficiency, large forming size, high material utilization rate, relatively low equipment investment and the like, and is particularly suitable for large thin-wall parts, near-net forming rib plates and personalized large-size components. However, WAAM is still essentially a strongly unbalanced solidification-repeated thermal cycling process in that materials undergo melting, solidification, reheating, localized resolubilization and re-precipitation during layer-by-layer deposition, and therefore the texture and performance are highly dependent on thermal history. For aluminum alloys, particularly Al-Cu based 2XXX alloys, WAAM are susceptible to stacking during processing. Firstly, electric arc heat input and interlayer heat accumulation can induce columnar crystal proportion to be increased, interlayer tissue difference to be enlarged and macroscopic layering to be carried out, secondly, defects such as hydrogen holes, shrinkage cavities, oxide inclusions and the like can be enriched among the layers and become crack initiation sources during subsequent stretching, thirdly, solidification segregation and inter-channel overlapping can enable crystal boundaries/dendrites to form continuous network eutectic or coarse second phases, cracks can be expanded along the fragile phases preferentially under stretching or fatigue loading, and fourthly, sampling in different directions can show obvious anisotropism and uniformity deficiency. The prior art has shown that the major bottlenecks of aluminum alloys WAAM are concentrated in terms of porosity, residual stress, and thermal cracking propensity, and that additional attention is paid to the continuous network-like second phase, intra/inter layer structure differences, and time-efficient response differences for al—cu based materials. Studies have suggested that a low heat input deposition mode is beneficial to reducing thermal cracking and voids, that proper deposition strategies, interlayer temperature control and artificial aging help reduce directional performance differences, and that subsequent heat treatment can transform the continuous network-like second phase into a more diffuse strengthening phase distribution. However, the prior art still has two outstanding shortcomings. Firstly, many schemes only emphasize deposition forming parameter optimization, but neglect to carry out systematic correction through a post-treatment process after deposition is completed, and secondly, other schemes are only used for single-grade or single-heat treatment formula, lack of parameter determination principles applicable to a wider range of 2XXX systems, and are difficult to form a full-flow process system of 'material selection-deposition control-heat treatment synergy-uniformity evaluation'. Especially for engineering applications it is not sufficient to pursue only the highest tensile strength in one direction. The uniformity of the organization and mechanical properties of the materials is also important for large thin-wall bearing members, storage tank ring segments, shell reinforcing structures and other actual engineering members. Therefore, while improving the overall strength, it is necessary to consider how to reduce the performance deviation between the scanning direction and the deposition direction, thereby improving the service reliability and structural designability. Therefore, it is highly desirable to provide a full-flow integrated method for 2XXX serie