The effect of short glass fibers on the process behavior of polyamide 12 during selective laser beam melting. (March 2020)

• Record Type: Journal Article
• Authors: Lanzl, Lydia; Wudy, Katrin; Drummer, Dietmar
• Is Part Of: Polymer testing. Volume 83(2020)
• Publication Date: 2020-03
• Subjects: Selective laser sintering -- Filled systems -- PA 12 -- Short glass fibers -- Additive manufacturing; Polymers -- Testing -- Periodicals; Polymères -- Tests -- Périodiques; 620.1920287
• DOI: 10.1016/j.polymertesting.2019.106313
• Languages: English
• ISSNs: 0142-9418

Abstract

Abstract: In additive manufacturing, polymer composites are used for setting tailored properties. Short glass fibers can be used as fillers for polyamide 12 for enhancing stiffness or tensile strength as well as for reducing shrinkage. In this paper, the effects of short glass fibers on polyamide 12 concerning powder properties, process behavior and part properties in laser beam melting of polymers (SLS) are investigated. It could be shown that by increasing the short glass fiber content powder properties as well as part properties are immensely affected. By adding glass fibers, powder properties, like flowability and diffuse reflection decrease. The isothermal crystallization changes resulting in a narrower processing window. Concerning mechanical properties, short glass fibers allow for a higher stiffness until a critical limit of filler concentration within this study is reached, after which the tensile strength decreases. The elongation of break decreases by rising the filler content. Highlights: The isothermal crystallization behavior of glass fibers on polyamide 12 during selective laser beam melting is detected. Theoretical considerations and calculations concerning the critical fiber length in selective laser beam melting are made. The optical behavior of the powder systems is changed due to glass fillers. Above the critical fiber content of around 30 vol.-%, the part porosity gets too high due to unsufficient wetting.