Cyclic plasticity of additively manufactured metals

This book chapter first explains some fundamentals of additive manufacturing of metals. The scanning strategies and printing parameters in the framework of selective laser melting technology are discussed with special attention paid to the influence of printing parameters on mechanical properties, the density of printed material, and surface roughness. Then, studies on the anisotropy of metallic alloys prepared by additive manufacturing, namely Ti-6Al-4V and maraging steel, are discussed, showing the importance of anisotropic yield criterion consideration in cyclic plasticity of models. The anisotropy of Ti-6Al-4V is also presented for cyclic plasticity investigated under uniaxial loading. A comparison of stress-strain behavior of stainless steel 316L follows. High yield strength of additively manufactured SS316L, gained without any heat treatment, leads to good ratcheting as well as low-cycle fatigue performance. Finally, the benefits of a new accelerated technique based on digital image correlation measurements considering standard fatigue test specimens are presented. Numerical modeling by a cyclic plasticity model with memory surface shows that the influence of mean stress and stress amplitude on uniaxial ratcheting behavior of additively manufactured SS316L is well described by the Abdel-Karim-Ohno kinematic hardening rule.