Correlation of Process Parameters with Mechanical Properties of Laser Sintered PA12 Parts

Eva C Hofland,Dagmar A Wismeijer,Ismet Baran

doi:10.1155/2017/4953173

Eva C Hofland, Dagmar A Wismeijer + Show 1 more

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https://doi.org/10.1155/2017/4953173

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Abstract

Selective laser sintering (SLS) is an additive manufacturing technique that enables the production of customized, complex products. SLS has proven itself a viable prototyping tool and production method for noncritical products. The industry has picked up on the potential of SLS, which raised the question whether it is possible to produce functional products with reproducible mechanical properties for application in critical sectors. Properties of SLS parts highly depend on the applied process settings. Hence, present work examined the influence of key process parameters (preheating temperature, laser power, scan spacing, scan speed, layer thickness, and part build orientation) on the properties (tensile strength, tensile modulus, elongation at break, and part density) of SLS produced parts. A design of experiments (DoE) approach was used to plan the experiments. Test samples according to DIN EN ISO 527-2 were produced on a sintering system (EOSINT P395) using polyamide 12 powder (EOS PA2200). Regression models that describe the relation between the process settings and resulting part properties were developed. Sensitivity analysis showed that mechanical properties of sintered parts were highly affected by layer thickness and scan spacing variations.

Highlights

Selective laser sintering (SLS) is an additive manufacturing technique which uses a laser beam to locally melt polymer powder to build products in a layer by layer fashion.During the past years, laser sintering of polymers has developed and grown into a viable prototyping tool and production method for customized, noncritical products
The utilized range of the process parameters is not presented in this work; the results are discussed based on Ein as defined in (4)
The corresponding Ein values can be seen in Table 1. “×” denotes sample sets that were excluded from the research since the applied settings did not result in successfully built samples

Summary

Introduction

Selective laser sintering (SLS) is an additive manufacturing technique which uses a laser beam to locally melt polymer powder to build products in a layer by layer fashion.During the past years, laser sintering of polymers has developed and grown into a viable prototyping tool and production method for customized, noncritical products (e.g., figurines, phone cases, and jewellery). Selective laser sintering (SLS) is an additive manufacturing technique which uses a laser beam to locally melt polymer powder to build products in a layer by layer fashion. The industry has seen the potential of selective laser sintering, which raised the question whether it is possible to apply SLS to produce fully functional products with reproducible mechanical properties. SLS has the potential to become the number one choice for small series production of high strength polymer parts. Comparison between conventional injection moulding and SLS has shown that up to 1,000 parts SLS is more economical [1]. A schematic visualization of the SLS fabrication process and an overview of the production process are given in Figures 1 and 2

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