In situ alloying: investigation of the melt pool stability during powder bed fusion of metals using a laser beam in a novel experimental set-up

Fabian Hofstaetter,Constantin Jugert,Katrin Wudy,Andreas Wimmer,Michael F. Zaeh

doi:10.1007/s40964-021-00233-y

Fabian Hofstaetter, Constantin Jugert + Show 3 more

Open Access

https://doi.org/10.1007/s40964-021-00233-y

Copy DOI

Abstract

The limited access to materials for the Powder Bed Fusion of Metals using a Laser Beam (PBF-LB/M) is compensated by in situ alloying. Individual melt pool characteristics can be specifically influenced to improve the mechanical properties of the final part. However, conventional PBF-LB/M machines allow only limited access for detailed observation of the process zone and, in particular, the melt pool. This paper presents a methodology for systematically analyzing the melt pool in the cross section to determine the in situ variation of the melt pool depth. A custom PBF-LB/M test bench was devised to enable investigation of the process zone using high-speed infrared cameras. The image data were processed automatically using a dedicated algorithm. The methodology was applied to analyze the effect of additives on the melt pool stability. Stainless steel 316L powder was blended with the aluminum alloy AlSi10Mg by up to 20 wt.%. It was found that the blended powder significantly reduced the variation of the melt pool depth.

Highlights

Introduction and state of the artPowder Bed Fusion of Metals using a Laser Beam (PBFLB/M) enables the production of geometrically complex parts [1]
This section gives a detailed description of the powder blending, the experimental set-up, and the methodology used for determining the melt pool depth using high-speed thermographic imaging
This study provides a methodology to systematically analyze the melt pool depth during PBF-LB/M

Summary

Introduction

Powder Bed Fusion of Metals using a Laser Beam (PBFLB/M) enables the production of geometrically complex parts [1]. In the PBF-LB/M process, a laser irradiates the cross section of a component in a powder layer. Adapted to rapid prototyping only, it is reaching a level of maturity that allows large-scale production. This emerging technology provides new opportunities in the fields of metallurgy, material science, and production. There are several risks and drawbacks that need to be addressed [2]. To fulfill the needs of upcoming PBF-LB/M applications, it is inevitable that special alloys will be required. Most materials used in the PBF-LB/M process were created and optimized for casting or forging operations, in which

Methods

Results

Conclusion