The physically based constitutive modeling, simulation and experimental of a superplastic forming and diffusion bonding (SPF/DB) process were studied for the manufacture of a pyramid lattice Ti-6Al-4 V sandwich panel structure. The high-temperature deformation behaviors of Ti-6Al-4 V were studied using uniaxial tensile tests at various temperatures 860 – 950 °C and strain rates 0.0001 s⁻¹ ~ 0.01 s⁻¹, corresponding microstructures were observed using optical microscope (OM) and Electron Backscattered Diffraction (EBSD). Based on obtained flow behavior and microstructure, a set of physically based constitutive equations of the Ti-6Al-4 V was established and used to simulate the superplastic forming for a pyramid lattice sandwich panel. The thinning ratios, dislocation densities, grain sizes and damage distributions of the sandwich panels were successfully predicted by the finite element (FE) simulation. A pyramid lattice Ti-6Al-4 V alloy sandwich panel with good dimensional accuracy and mechanical properties was manufactured by the SPF/DB process at 920 °C with a gas loading path of 0.0005 MPa/s. The maximum thickness thinning ratio, damage factor and relative grain size at the ribs of the sandwich panel were 26.3%, 6.7% and 0.94, respectively. The established constitutive model aids the FE simulations of SPF/DB manufacture of sandwich panels’ structure enabling both macro- and micro-properties to be synergistically controlled and guides the practical process optimizations.

研究了用于制造金字塔晶格 Ti-6Al-4 V 夹层板结构的超塑性成形和扩散结合 (SPF/DB) 过程的基于物理的本构建模、模拟和实验。使用单轴拉伸试验研究了 Ti-6Al-4 V 在 860 – 950 °C 和应变速率 0.0001 s ^-1  ~ 0.01 s ^-1下的高温变形行为，使用光学显微镜（OM）和电子背散射衍射（EBSD）观察相应的微观结构。基于获得的流动行为和微观结构，建立了一组基于物理的 Ti-6Al-4 V 本构方程，并用于模拟金字塔格子夹层板的超塑性成形。通过有限元（FE）模拟成功地预测了夹层板的减薄率、位错密度、晶粒尺寸和损伤分布。采用 SPF/DB 工艺在 920 °C 和 0.0005 MPa/s 的气体加载路径下制造了具有良好尺寸精度和机械性能的金字塔晶格 Ti-6Al-4 V 合金夹芯板。夹芯板肋部的最大厚度减薄率、损伤系数和相对晶粒尺寸分别为26.3%、6.7%和0.94。