Contamination of a Recirculated Powder Material during Selective Laser Synthesis

Abstract

The contamination of the recirculated powder, namely, the material retained after the selective laser sintering of VZh159 and EP648 alloys, is studied as a function of the geometry of a part. The contamination of the recirculated powder is shown to depend mainly on the complex geometry of the part with a long perimeter of its contours and supporting elements rather than on the area of the section to be sintered. The main source of the contamination of the recirculated powder is represented by ejected particles, i.e., secondary granules, which form during a local microexplosion in the focal laser spot on a powder layer. The laws of ejection formation during synthesis are determined as functions of the type of part element to be synthesized.