超声振动因子对镁合金单点渐进成形板材性能影响规律

Rules of Impact of Ultrasonic Vibration Factor on Performance of Magnesium Alloy Sheet in Single Point Incremental Forming

研究并掌握施加超声振动后镁合金板材在各成形参数下的成形规律,对解决温渐进成形带来的材料受热不均、随着温度的改变润滑薄膜在局部高温下引起的粘着、模具强度和寿命随温度升高而降低等问题,完善镁合金超声振动单点渐进成形工艺有着重要的理论和实际应用价值。以方锥盒形件为研究对象,以最大剪切应力、减薄率和成形精度为指标,分析不同参数:工具头尺寸、板厚和振幅对镁合金板材超声振动单点渐进成形性能的影响。结果表明:施加超声振动后,最大剪切应力和最大减薄率均有明显的降低,成形精度有明显的提高且在工具头直径D=10 mm,板厚h=1.0～1.3 mm,振幅A/2=0.04 mm,成形性能改善最为明显。

It is very important to research and master the rule of incremental forming of magnesium alloys with ultrasonic vibration under different process parameters for theoretical and practical application. This has significant value of theory and engineering application to solve the deficiencies, such as plate uneven heating and heating slower, adhesion of the lubricant film caused by partial higher temperature with the changing temperature, the decline of mold strength and service life with the increase of temperature, and to improve the progress of the magnesium alloy plate ultrasonic vibration single point incremental forming. We took the square pyramid box for research, and the maximum shear stress, reduction ratio, forming accuracy as indexes to analyze the influence of different parameters on the magnesium alloy plate ultrasonic vibration single point incremental forming, including the tool head size, the thickness, and the amplitude. The results show that the maximum shear stress and the maximum reduction are obviously reduced after applying ultrasonic vibration, and the forming accuracy is markedly improved; when the tool head diameter is 10 mm, thickness is 1.0-1.3 mm, and the amplitude（A/2） is 0.04 mm, the forming properties are improved most significantly.