钛合金超塑成形/扩散连接四层结构表面沟槽控制方法研究

Research on Control Method of Surface Groove of Titanium Alloy SPF/DB Four-Sheet Structure

通过有限元数值模拟和物理试验相结合方法,对超塑成形/扩散连接(SPF/DB)四层结构表面沟槽形成原因进行了分析和研究,采用正交试验方法分析了应变速率έ、扩散连接宽度b、芯层与蒙皮厚度比t和摩擦系数u这4个因素对蒙皮表面沟槽深度的影响。结果表明,对蒙皮表面沟槽形成影响最大的因素为芯层与蒙皮厚度比t。通过试验研究,提出了一种对蒙皮表面施压背压的方法,可有效避免或控制超塑成形/扩散连接四层结构蒙皮表面沟槽的形成。

In this paper,through the combination of the finite element numerical simulation and the actual test,the causes of the surface groove formation of superplastic forming/diffusion bonding(SPF/DB)four-sheet structure are analyzed and studied.The orthogonal test method is used to analyze the influence of four factors on the surface groove of the panel,including the strain rateέ,the diffusion connection width b,the thickness ratio t of the core plate to the panel and the friction coefficient u of the die.It can be seen that the thickness ratio t of the core plate to the panel is the most important factor of the surface groove of the panel.Based on the experimental study,a method of pressing 0.2MPa back pressure on the panel surface is proposed,which can effectively control the formation of the surface groove of SPF/DB four-sheet structure.