On the Influence of AlSi10Mg Powder Recycling Behavior in the LPBF Process and Consequences for Mechanical Properties

C Weiss,J Munk,C L Haefner

doi:10.1007/s11837-021-05080-4

C Weiss, J Munk + Show 1 more

Open Access

https://doi.org/10.1007/s11837-021-05080-4

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Abstract

By using additive manufacturing techniques like the laser powder bed fusion (LPBF) process, parts can be manufactured with high material efficiency because unfused powder material can be reconditioned and reused in consecutive manufacturing jobs. Nevertheless, process by-products like spatters may influence the powder quality and hence alter the mechanical properties/performance of parts. In order to investigate these dependencies, a methodology and a standard build job for the recycling behavior of the lightweight aluminum alloy AlSi10Mg was developed and built with ageing powder in 10 consecutive jobs with no refreshing between the cycles. The powder properties and mechanical performance of parts at static load for two build directions (horizontally and vertically to substrate plate) was evaluated. The influence of build height effects on mechanical performance was investigated as well. The findings may indicate that the coarsening of the powder material during recycling could lead to improved mechanical properties for the AlSi10Mg alloy.

Highlights

OF THE ART Additive manufacturing (AM) techniques like the laser powder bed fusion (LPBF) process allow for manufacturing of highly complex, three-dimensional, and near net shape parts without cost intensive tools
For Asgari et al.[5] no information on the build job layout is given, while the used powder material is well below typical ranges of particle size distribution for the LPBF process and not representative for state of the art applications
Powder recycling/reuse in laser powder bed fusion allows for higher material usage and better ecological and economical efficiency

Summary

INTRODUCTION

AND STATE OF THE ART Additive manufacturing (AM) techniques like the laser powder bed fusion (LPBF) process allow for manufacturing of highly complex, three-dimensional, and near net shape parts without cost intensive tools. For Asgari et al.[5] no information on the build job layout is given, while the used powder material is well below typical ranges of particle size distribution for the LPBF process (typically = 10–60 lm according to Vock et al.4) and not representative for state of the art applications. The influence of recycling Ti6Al4, IN718, Scalmalloy, and AlSi10Mg on changes in powder properties was studied in Cordova et al.[9] The 6 times recycled AlSi10Mg powder material showed a higher particles size distribution compared with the virgin powder. It is stated that lightweight alloys like Ti6Al4V and AlSi10Mg are most influenced by recycling, provoked by changes in particle size distribution and affecting the powder flowability. The powder properties (chemical composition, particle size distribution, flowability, and morphology) as well as the static mechanical performance of tensile samples were investigated. Calculations of correlation factors help us to understand the influences of powder reusage in LPBF

METHODOLOGY AND ANALYSIS METHODS

CONCLUSION AND OUTLOOK

Findings

CONFLICT OF INTEREST