A 3D printed magnesium alloy with an interpenetrating NiTi phase shows remarkable strength, damping, and self-healing properties.

In this work, copper–tungsten (Cu-W) composites with a cubic and rhombic dodecahedron W-skeleton were fabricated by the infiltration of Cu melt into a three-dimensionally printed W scaffold. The effects of the skeleton structure on the mechanical properties and energy-absorbing characteristics of the Cu-W interpenetrating-phase composite were investigated and compared with those of commercial Cu-W composite fabricated by powder metallurgy. The results indicated that the mechanical properties of the studied Cu-W interpenetrating-phase composites were mainly related to the properties of their ordered skeletons. Compared to the dodecahedron W-skeleton Cu-W composites, cubic-W-skeleton Cu-W composites exhibited higher strengths but lower absorbed energy. The Cu-W composites with ordered W-skeletons displayed much higher energy absorption than the commercial Cu-W ones. By adjusting the ordered W-skeleton structure contained in the composite, the strength and deformation behavior of the Cu-W composite can be effectively improved, which provides a guide to optimizing the mechanical properties and energy absorption of Cu-W composites.

The hydrogen embrittlement (HE) behavior of a selective laser-melted (SLM) 316L austenitic stainless steel has been investigated by hydrogen charging experiments and slow strain rate tensile tests (SSRTs) at room temperature. The results revealed that compared to the samples without H, the ultimate tensile strength (UTS) and elongation (EL) of specimens were decreased from 572 MPa to 552 MPa and from 60% to 36%, respectively, after 4 h of electrochemical hydrogenation with a current density of 100 mA/cm². The negative effects of hydrogen charging were more pronounced on the samples’ ductility than on their strength. A quasi in situ EBSD observation proved that there was little phase transformation in the samples but an increased density of low angle grain boundaries, after 4 h H charging. After strain was applied, the surface of the H-sample displayed many hydrogen-induced cracks along the melt pool boundaries (MPBs) showing that these MPBs were the preferred areas for the gathering and transferring of hydrogen.