Untersuchungen zum Elektronenstrahl-Randschichtumschmelzen einer sprühkompaktierten übereutektischen eisenhaltigen Al-Si-Legierung: Investigations on electron beam surface remelting of spray-formed iron containing hypereutectic Al-Si alloy

The present study shows the influence of two different electron beam deflection techniques on surface deformation, microstructure and hardness after an electron beam surface remelting of a spray-formed hypereutectic aluminium alloy (AlSi17Fe5Cu4Mg). Due to the specific rapid heating and cooling rates on the one hand and the high content of alloying elements on the other hand, the surface microstructure was modified by phase formation, grain refinement and an oversaturation of aluminium solid solution. As a result the hardness was threefold increased (284 HV 0.1) compared to the untreated base material (104 HV 0.1). This hardness increase was significantly higher than the level of the conventional heat treatment (e. g. age hardening approx. 170 HV 0.1). The remelting process largely influenced the wear behaviour under abrasive (scratch test) and abrasive-adhesive (pin-on-disc test) load conditions. Remelted surface layers generated by meander deflection technique showed the most improvement regarding their wear performance. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim