Strain rate dependency of laser sintered polyamide 12

Abstract

Abstract. Parts processed by Additive Manufacturing can now be found across a wide range of applications, such as those in the aerospace and automotive industry in which the mechanical response must be optimised. Many of these applications are subjected to high rate or impact loading, yet it is believed that there is no prior research on the strain rate dependence in these materials. This research investigates the effect of strain rate and laser energy density on laser sintered polyamide 12. In the study presented here, parts produced using four different laser sintered energy densities were exposed to uniaxial compression tests at strain rates ranging from 10 −3 to 10 +3 s −1 at room temperature, and the dependence on these parameters is presented.

Impact Behavior of Additively Manufactured Stainless Steel Auxetic Structures at Elevated and Reduced Temperatures

“…Strain rate‐ and temperature‐dependent properties of the additively manufactured materials have been investigated in papers focused mainly on strain rate dependency of polymers, [ 13–15 ] mechanical characterization of the Inconel superalloy, [ 16 ] the thermomechanical model of a titanium alloy, [ 17 ] and strain rate dependency of the printed bulk stainless steel. [ 18 ] In the case of similar materials, temperature‐dependent penetration resistance of the aluminum foam sandwich panels has been investigated numerically.…”

Effects of Build Orientation and Strain Rate on the Tensile-Shear Behaviour of Polyamide-12 Manufactured Via Laser Powder Bed Fusion

“…Unlike metals or ceramics, polymers possess rather high sensitivity to strain rate as their strength can be double or tripled with the increasing strain rate by several orders in magnitude [29,30]. Despite the increasing number of studies on the mechanical behaviour of polymer PBF parts, research into their rate dependency is still limited [20,27,31,32]. Mehdipour et al [20] assessed the rate dependency together with the anisotropy of L-PBF printed PA12 tensile dog-bone specimens manufactured in three build orientations; rate dependency of the tensile strength and elongation to break were observed within a low strain rate range on the order from 10 − 3 to 10 − 2 s − 1 .…”

“…Mehdipour et al [20] assessed the rate dependency together with the anisotropy of L-PBF printed PA12 tensile dog-bone specimens manufactured in three build orientations; rate dependency of the tensile strength and elongation to break were observed within a low strain rate range on the order from 10 − 3 to 10 − 2 s − 1 . Cook et al [31] conducted mechanical testing of L-PBF processed polyamide in a wide range of strain rates (10 − 3 to 10 3 s − 1 ) to construct an Eyring plot of flow stress versus logarithm of strain rate and demonstrated a significant strain-rate dependence. This rate-dependence, often a bi-linear response at high rates, has been shown to be a material property and is due to the movement of the β transition to room temperature at these rates.…”

A Computational Geometry Generation Method for Creating 3D Printed Composites and Porous Structures

“…Materials 2021, 14, 2507 2 of 9 Furthermore, new materials and technologies offer promising opportunities in designing better protection equipment. Strain rate sensitive materials suitable for additive manufacturing techniques [16] can be combined with intelligent designs to enhance impact energy absorption. Lightweight lattice structures can be designed to absorb substantial amounts of energy and outperform conventional materials [17][18][19].…”