Sustainable laser metal deposition of aluminum alloys for the automotive industry

Abstract

In the last few years, there has been increasing interest in the processing of aluminum alloys using additive manufacturing (AM) processes. Thanks to their properties, aluminium alloys are extensively used in aerospace, rail, and automotive industries. Laser metal deposition (LMD), among the AM processes, can manufacture complex features as well as reinforcement structures on pre-existing complex parts. The work performed within the SAMOA project aims to expand the knowledge of the material properties of aluminum alloys when the LMD process is performed under atmospheric conditions. Both common alloys (AlSi10Mg, AlSi1Mg) and AM-specific alloys (AM205 and AlSi1Mg + 1 wt. %Zr) were analyzed and compared. Results show significantly lower amounts of internal defects and higher mechanical properties in AM-specific alloys. This database of mechanical properties will be used to design, simulate, and fabricate reinforcement structures on car frames to enhance their crash resistance and increase vehicle security. Moreover, to reduce material waste, the SAMOA project focuses also on the effects of powder recycling by analyzing both chemical and physical changes in the powder. The higher concentration of oxygen and hydrogen was separately analyzed by artificially increasing their concentration by heat treating AlSi10Mg powder. Results showed similar processability with a reduction in UTS of −31.4% and an increased elongation at fracture of +112.5%. Recycled powder, on the other hand, could not be easily collected, sieved, and reused since the identified physical and chemical changes of the powder lower its processability.