Crystallographic texture and mechanical properties by electron beam freeform fabrication of copper/steel gradient composite materials

Abstract

Copper/stainless steel gradient material was preparated by electron beam freeform fabrication. With the increase of deposition layers, the interfaces between them become smooth. Crystallographic textures at the first, third and fifth copper layers were determined by means of electron backscatter diffraction analysis. The results yielded clear information that grain growth was significantly affected by heat dissipation. The grain gradually altered from competitive growth to epitaxial growth with the increase of the layers. A strong crystallographic texture in <0 0 1> direction is produced on the top of the deposition, but weak at the bottom of the deposition. Cracks and shrinkages were found in the deposition, which are attributed to the liquid copper. The average shear strength of the depositions exceeds 240 MPa. The fracture is primarily characterized by a ductile mode.