This paper presents the cyclic deformation behaviour and fatigue properties of a wire + arc additive manufactured Ti-6Al-4V alloy in the as built condition under strain-controlled test condition. Higher local energy input used to build the material has resulted in a coarser primary columnar β grain structure along with a coarser α microstructure compared to Ti-6Al-4V alloys produced by other additive manufacture processes. Test specimens were manufactured in horizontal and vertical orientations with respect to the deposited layers. Isotropic fatigue property was observed at lower applied strain values. When the strain amplitude was above 0.6%, the vertical samples, where the loading axis was parallel with the primary columnar β grains, showed marginally higher fatigue life owing to the material being more ductile in this direction. Moreover, higher cyclic softening rate by a factor of two was measured in the vertical samples. No porosity defects were found in the material. Cracks were initiated from either the α laths or α/β interface due to cyclic slip localisation.

本文介绍了线材 + 电弧添加剂制造的 Ti-6Al-4V 合金在应变控制测试条件下的循环变形行为和疲劳性能。与通过其他增材制造工艺生产的 Ti-6Al-4V 合金相比，用于构建材料的更高局部能量输入导致更粗的主柱状 β 晶粒结构以及更粗的 α 微观结构。相对于沉积层在水平和垂直方向上制造测试样本。在较低的施加应变值下观察到各向同性疲劳特性。当应变幅度高于 0.6% 时，加载轴与主要柱状 β 晶粒平行的垂直样品显示出略高的疲劳寿命，因为材料在这个方向上更具延展性。而且，在垂直样品中测量到高两倍的循环软化率。在材料中没有发现孔隙度缺陷。由于循环滑移局部化，裂纹从 α 板条或 α/β 界面开始。