| Abstrakt: |
The possibilities for improvement of the surface characteristics of selective laser melting (SLM) steel 1.2709 by reactive electro-spark treatment both in contact and non-contact modes using low-melting AlSi-based electrodes are investigated. The results of studies of the topography, roughness, hardness, composition, thickness, and structure of the obtained surface layers depending on the pulse energy within the range 0.1-0.7 J are represented. Dense and uniform layers having microhardness of 8-10 GPa and amorphous-crystalline structure containing in-situ formed intermetallics as AlFe, FeSi, Al5Fe2, AlFe0.23Ni0.77, Fe0.9Si0.05, also Al2O3, AlN were obtained. Their thickness (5-15 µm) and roughness within the range of Ra=3-8 µm, can be changed by changing the pulse energy. So, improved properties of the modified surfaces have been achieved, in terms of erasing the traces of the pre-treatment and reducing surface roughness, as well as their strengthening, which suggest increased wear resistance as a response of the newly formed compounds in the form of nanocrystalline and amorphous phases. [ABSTRACT FROM AUTHOR] |
