Anisotropy of Additive Microstructure
Anisotropy of additively manufactured microstructure: Mechanical properties vary with direction because dendrites solidify directionally along the build direction.
Physical-Chemical Mechanism
In additive manufacturing, metal melts grow into directional structures (dendrites). These dendrites solidify along the build direction, leading to an uneven distribution of mechanical properties.
Metallurgical Relevance & Risks in Welding
Anisotropy can cause different stress states and mechanical deformations in different directions. This increases susceptibility to cracking, especially when the material is under load. Additionally, mechanical properties may be uneven, leading to unexpected failure or fracture.
Shop Practice & Guidelines
When welding additively manufactured steels, it is important to ensure uniform cooling and careful control of the build direction. Use a consistent welding heat input and pay attention to the correct alignment of the laser or electrode. If necessary, perform post-processing treatments to minimize anisotropy.