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In-Depth Information
bronze, which wicks into the empty spaces
and fills them (
Figure 9-5
). The finished mod-
el is a kind of stainless steel sponge filled with
bronze, and can be given a variety of surface
treatments, including plating with gold or
other metals.
Figure 9-4.
UV-curing acrylic, via photopolymer jet-
ting
Metals
Direct Metal Laser Sintering
(DMLS)
Direct metal laser sintering uses a laser to di-
rectly fuse certain metal powders, such as ti-
tanium, in a fashion very similar to SLS in
plastics. Other specialty alloys can be printed
via DMLS, but high costs and stricter design
guidelines make the process less accessible
to beginners.
Figure 9-5.
Bronze-infused stainless steel, via direct
metal printing
Indirect Printing Methods
Indirect printing methods create positive or
negative models that can be used with con-
ventional casting processes to create metal
parts. For instance, a sacrificial model of a
part can be 3D printed in a wax-like resin us-
ing stereolithography, and then duplicated
in metal using the traditional lost-wax pro-
cess. Alternately, the powder bed/inkjet pro-
cess can be used to print molds in silica sand
or other traditional foundry media, which are
then used to cast metal parts in the normal
way.
Direct Metal Printing
Direct metal printing uses a multistep meth-
od to create powder-based metallic models,
mainly from stainless steel. First, the object
is printed into a bed of very fine stainless
steel powder using the inkjet-binder pro-
cess.
A carefully controlled heat treatment then
burns out the plastic binder and fuses the
steel particles together. Finally, the porous
sintered model is infused with molten
Dr. Stuart Deutsch is a materials consultant in
the NYC area and executive editor at
Tool-
Guyd.com
.
