Product Design and Simulation for Metal Binder Jetting - An investigation of sintering deformation and design compensation in Simufact Additive
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Product development (MPPDE), MSc
Publicerad
2023
Författare
Andersson , Simon
Dawson, Garrett
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Metal Binder Jetting (MBJ) is an Additive Manufacturing (AM) method in which
parts are built layer-by-layer using metal powder and a selectively deposited liquid
bonding agent. MBJ can produce complex geometries with competitive physical
properties. The as-printed part must undergo sintering to densify the component
from ~50% to over 95% relative density and to achieve the desired physical properties.
This densification corresponds to linear part shrinkage on the scale of 20%
in addition to other deformations that may result from the high-temperature process.
Shrinkage and deformation act as obstacles to creating parts with required
geometrical tolerances when using MBJ.
Simulations of the sintering stage of the process present one possible way to improve
geometry when addressing and compensating for shrinkage and deformation.
The Simufact Additive Binder Jet module, developed by Hexagon AB, uses a finite
element analysis (FEA) simulation of the sintering process and material model to
predict the change of the geometry and the deviation from the desired tolerances.
Additionally, there is the option to create a compensated, pre-deformed geometry
that should sinter to the desired geometry based on the simulation results. This
work has focused on investigating the sensitivity of input parameters of the simulations
and the accuracy of simulation predictions compared to experimentally printed
and sintered parts.
Investigation of simple 10mm cube geometries has shown that the Simufact simulations
predict shrinkage on a similar scale to previous research but underestimate the
shrinkage anisotropy in the build direction. When using the default material model,
the pre-deformed geometry created by Simufact lead to an improvement in compliance
with geometrical tolerances in 3 out of 5 tested geometries after sintering. An
adjusted model applied to a complex geometry showed improved results from the
default settings but with room for further improvement, indicating that adjusting
simulation settings can improve simulation fidelity compared to real parts. Adjustments
to the material model showed a more substantial influence on the results
of simulation compared to adjustments in the sintering profile, with temperature
notably showing little to no effect on predicted densification.
Beskrivning
Ämne/nyckelord
additive manufacturing , metal binder jetting , Simufact Additive , Sintering , shrinkage , deformation , simulation , design compensation