Influence of powder characteristics in additive laser manufacturing of SS 316L metallic parts

Abstract

Laser direct metal deposition (LDMD) is a rapid manufacturing technique, with high potential for development, from new part construction to worn or defective part repair, with various metallic alloys. Thanks to their long experience in the field of laser cladding, IREPA LASER has developed specific tools adapted to the rapid manufacturing of metallic parts based on their patented coaxial powder cladding nozzle.The process is well developed, but depends on numerous parameters, which can affect the stability and the quality of the result. Thus, the powder characteristics are multiple (grain size distribution, morphology, chemical composition …) and crucial for optimal process behavior, and mechanical properties.This paper focuses on powder investigation, for a better understanding of its influence. The work was performed with different batches of stainless steel AISI316L, processed with a single mode fiber laser. The characteristics of the different powders were analyzed before processing, and the manufactured samples were investigated. The process is flexible when the powders meet the specifications, but has to be tuned according to the specific characteristics of the powder. This paper discusses the results obtained, and highlights the influence of the main characteristics of the powders.Finally, by using these results, some parts were manufactured, particularly with a full 5 axis machine and by setting up 3D configuration, in order to demonstrate the merits of the process.Laser direct metal deposition (LDMD) is a rapid manufacturing technique, with high potential for development, from new part construction to worn or defective part repair, with various metallic alloys. Thanks to their long experience in the field of laser cladding, IREPA LASER has developed specific tools adapted to the rapid manufacturing of metallic parts based on their patented coaxial powder cladding nozzle.The process is well developed, but depends on numerous parameters, which can affect the stability and the quality of the result. Thus, the powder characteristics are multiple (grain size distribution, morphology, chemical composition …) and crucial for optimal process behavior, and mechanical properties.This paper focuses on powder investigation, for a better understanding of its influence. The work was performed with different batches of stainless steel AISI316L, processed with a single mode fiber laser. The characteristics of the different powders were analyzed before processing, and the manufactu...