3D printing is increasingly being used as an alternative method of manufacturing components. In particular, replacement parts that were manufactured via traditional methods such as casting are now being made using additive manufacturing processes. While a printer can produce a dimensionally identical part, the process may not produce the same residual stress distribution in the part. The repeated cycles of heating and cooling that are required to deposit the layers of metal cause localized expansion and contraction, which in turn can create residual stress.
Finished components may be similar dimensionally, chemically, and microstructurally. However, they may have significantly different resistances to fatigue, stress corrosion cracking, and other life-limiting influences due to differences in residual stress.
X-ray diffraction can be used to quantify the difference in residual stress in 3D printed parts vs. traditionally manufactured parts. Additionally, we can determine other material differences such as grain size, percent crystallinity, texture, and dislocation density. This information can then be used for post-printing stress management processing such as heat treatment, stress relief, and surface enhancement.
