Influence of erbium addition on the defects of selective laser-melted 7075 aluminium alloy

Selective laser-melted (SLMed) 7075 aluminium alloy is prone to cracking. Erbium (Er) could modify the alloys prevent cracking in traditional manufacturing processes. In present study, Er-modified powders are prepared investigate influence of Er element on crack reduction SLM. The evolution characterised by a scanning electron microscope (SEM), X-ray diffraction (XRD) and high-resolution transmission (HRTEM). results show that density reduced with addition, but porosity increases, new discovery. Based SEM TEM results, addition exists form unmelted particles Al3Er sub-micrometer scale. molten pool deteriorate fluidity result higher porosity. coherency between matrix favours grain refinement, therefore reduction.