论文部分内容阅读
提出了一种钛合金三维点阵夹层结构制备方法,采用超塑成形/扩散连接工艺(SPF/DB)制备了金字塔型、四面体型、X型三维点阵夹层结构,在SPF/DB制备工艺中,采用的是五层板材,四层超塑成形工艺,成形出的结构是三层夹层结构,其中扩散连接工艺为:920℃/2 MPa/2 h,超塑成形工艺为:920℃/2 MPa/2 h。通过压缩试验测试了不同点阵结构类型、单元尺寸、点阵层数的压缩性能,并进行了对比分析。研究表明,钛合金三维点阵结构在压缩变形机制主要包括:弹性变形、弹性屈曲、塑性屈曲、筋条断裂,这些变形机制导致点阵结构的压缩曲线呈现应力波动的特征。四面体点阵结构具有最高的抗压强度,金字塔型点阵结构具有最高的抗压模量,X型点阵结构的抗压强度最小,抗压模量居中。随着单元尺寸和点阵层数的增加,钛合金三维点阵的抗压强度和抗压模量迅速降低。
A preparation method of 3D lattice sandwich structure of titanium alloy was proposed. Pyramid, tetrahedron and X-type 3D lattice sandwich structures were fabricated by superplastic forming / diffusion bonding process (SPF / DB) , The five-layer plate and four-layer superplastic forming process are adopted, and the formed structure is a three-layer sandwich structure in which the diffusion bonding process is 920 ° C / 2 MPa / 2h and the superplastic forming process is 920 ° C / 2 MPa / 2 h. Compressive tests were carried out to test the compressibility of different lattice structure types, cell sizes and lattice densities, and the comparative analysis was carried out. The results show that the three dimensional lattice structure of titanium alloy mainly includes the elastic deformation, elastic buckling, plastic buckling and tendon fracture. These deformation mechanisms cause the compressive curve of the lattice structure to exhibit the characteristics of stress fluctuation. The tetrahedron lattice structure has the highest compressive strength, the pyramidal lattice structure has the highest compressive modulus, the X-type lattice structure has the lowest compressive strength and the middle compressive modulus. With the increase of cell size and lattice number, the compressive strength and compressive modulus of the 3D lattice of titanium alloy decrease rapidly.