Research on Producing Complex Metal Parts
with Lattice Structure, by Selective Laser Melting
MAGER Voicu
1,a
, BALC Nicolae
1,b
, LEORDEAN Dan
1,c
,
DUDESCU Cristian
1,d
and FOCKELE Matthias
2,e
1
Technical University of Cluj-Napoca, B-dul Muncii 103-105, 400641 Cluj-Napoca, România
2
ReaLizer GmbH, Hauptstraße 35, 33178 Borchen, Germany
a
Voicu.Mager@tcm.utcluj.ro,
b
nicolae.balc@tcm.utcluj.ro,
c
Dan.Leordan@mail.utcluj.ro,
d
mircea.dudescu@rezi.utcluj.ro,
e
M.Fockele@realizer.com
Keywords: selective laser melting, lattice structure, scaffold, bone ingrowth, interconnected pores.
Abstract. This study evaluates the manufacturability and performances of periodic cellular lattice
structures designed by repeating a cubic unit cell and produced by SLM using titanium powder. The
effects of unit cell size on the manufacturability, density, compression and bending properties of the
manufactured cellular lattice structures were investigated. Lattice structures manufactured with
various unit cell sizes ranging from 0.5 to 1.2 mm could be produced free of defects by the SLM
process, with a novel type of supports. By the increasing of the cell size, a decrease of the applied
load together with an enhancement of the flexure extension were observed. Specimens with a cell
size higher than 1 mm manifested an excellent flexibility during flexure tests.
Introduction
Selective Laser Melting (SLM) is one of the few rapid prototyping (RP) techniques which
enables the quick production of nearly unlimited complex geometries directly from metal powder
with no or minimal pre-processing and/or post-processing requirements. SLM allows the
manufacture of complex lattice structures which otherwise cannot be built by conventional
technologies. A growing interest in the SLM-fabrication is the production of porous objects,
because they manifest similar or superior properties to solid counterparts. For instance, porous
objects usually have larger internal surface areas and higher strength-to-weight ratios. For this
reason, interconnected pores can facilitate the passage of fluids and biological cells through which
biological tissues can be gradually grown and docked [1].
Micro-lattice block structures offer a significant potential for the usage in the design of
lightweight cellular structures. Experiments have shown that mechanical response of micro lattice
structures is governed by the micro-architecture of the structure [2].
The research presents the production and testing of such lightweight and at the same time
sustainable SLM-parts, with their possible applications. The focus is on the microstructure -
mechanical properties–local deformations relationship, which allows the optimization of load
adapted lattice structures. The final aim is to obtain personalized implants with mechanical
properties close to those of bone and to ensure their osseointegration. The SLM is considered a
viable alternative for achieving a precise control over the scaffolds architecture, the pore shape and
especially interconnectivity, which is crucial for the bone ingrowth. The manufactured and tested
samples offer important information about the degree of dependence of the compression and
bending properties of the lattice structures on the various unit cell sizes.
Porous Structures Made by SLM
Yan et al. [3] investigated the design and manufacturing of periodic cellular lattice structures
using a novel unit cell type called “Schoen Gyroid”, which possesses circular and smooth struts and
a spherical core. The inclination angle of the circular and smooth struts of the Gyroid unit cell
continuously varies along the spherical core, what leads to the fact that during the SLM process, the
Applied Mechanics and Materials Vol. 371 (2013) pp 280-284 Online: 2013-08-30
© (2013) Trans Tech Publications, Switzerland
doi:10.4028/www.scientific.net/AMM.371.280
All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans
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