Neutron Bragg edge imaging for strain and texture characterization of steel-copper multi-material obtained by laser powder-bed fusion

• Neutron Bragg edge imaging was applied to study 316 L/CuCrZr multimaterials specimens. • Texture depends on the orientation between the interfaces and the building direction. • 316 L had a texture along the (200) orientation, CuCrZr layer had a random texture. • Compressive strain was observed in the CuCrZr layer and tensile strain in 316 L layer. Bragg edge imaging has been applied to multi-material laser powder-bed fusion (M2LPBF) samples of 316 L stainless steel and CuCrZr. A multilayer sample with interfaces perpendicular to the building direction and a bilayer sample with parallel interfaces to the building direction were studied. The results demonstrate that this non-destructive approach does not only succeed in characterizing the different interdiffusion zones, but also strain and texture variations across the multiple material regions. In both samples the 316 L layers are found to display a strong (200) texture, while the CuCrZr layers exhibited either a random or weak (110) texture. In the multilayer samples, the difference in thermal expansion between CuCrZr and 316 L led to tensile residual strain in the steel layers and compressive residual strain in CuCrZr. The multilayer sample showed narrower intermixing zones at its horizontal interfaces, especially where CuCrZr was printed onto 316 L steel which is attributed to adjustments in the printing parameters that increase local heating in the formed layers. These results agree with conventional destructive characterizations used in this work. The non-destructive nature of the analyses can enable corresponding observations on the same sample before and after post treatments and/or mechanical testing, implying significant potential for future studies.