Fan Xiaobo, Sun Baoshan, Qu Wenliang, Chen Xianshuo, Wang Xugang
School of Mechanical Engineering, Dalian University of Technology, Dalian 116000, China.
School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150000, China.
Materials (Basel). 2023 Jul 1;16(13):4766. doi: 10.3390/ma16134766.
The thin-walled curved-surface component is an important structural element in aerospace. Wrinkling, springback and thermal distortion occur easily when forming these components. To form thin-walled components with high precision and strength, a two-layer-sheet hot-forming-quenching integrated process was proposed, in which wrinkling is prevented by thickening the upper sheet and springback is reduced by solution and die quenching. Selecting an appropriate upper sheet is crucial to suppress wrinkling and accomplish effective die quenching. The effect of the upper sheet on the wrinkling and strengthening behaviors of an Al-Cu-Mg-alloy melon-petal shell was thus studied in detail. The anti-wrinkle mechanism was analyzed through numerical simulation. The forming quality, including forming precision, deformation uniformity and strength, were further evaluated. The wrinkle gradually decreased with the increasing thickness of the upper sheet, resulting from the depressed compressive stress at the edge of the target sheet. A defect-free specimen with a smooth surface was finally formed when the thickness of the upper sheet reached three times that of the target sheet. The profile deviation was ±0.5 mm. Excellent thickness uniformity in a specimen can be obtained with a maximum thinning rate of 6%. The full strength, ranging from 455 to 466 MPa, can be obtained in all regions of the specimen, indicating that effective strengthening can be accomplished with the two-layer-sheet die quenching. The results indicated that high forming quality and full strength can be obtained in a two-layer-sheet hot-forming-quenching integrated process. This research has great potential for engineering applications using aluminum-alloy curved-surface thin-walled components.
薄壁曲面构件是航空航天领域中的重要结构元件。在这些构件的成形过程中，容易出现起皱、回弹和热变形等问题。为了高精度、高强度地成形薄壁构件，提出了一种双层板热成形-淬火一体化工艺，其中通过加厚上层板来防止起皱，并通过固溶处理和模具淬火来减少回弹。选择合适的上层板对于抑制起皱和实现有效的模具淬火至关重要。因此，详细研究了上层板对Al-Cu-Mg合金瓜瓣壳起皱和强化行为的影响。通过数值模拟分析了抗皱机理。进一步评估了成形质量，包括成形精度、变形均匀性和强度。随着上层板厚度的增加，皱纹逐渐减少，这是由于目标板边缘的压缩应力降低所致。当上层板厚度达到目标板厚度的三倍时，最终形成了表面光滑、无缺陷的试件。轮廓偏差为±0.5mm。试件可获得优异的厚度均匀性，最大变薄率为6%。试件所有区域均可获得455至466MPa的全强度，表明双层板模具淬火可实现有效的强化。结果表明，双层板热成形-淬火一体化工艺可获得较高的成形质量和全强度。本研究在铝合金曲面薄壁构件的工程应用方面具有很大潜力。
