Page 21 - MMI-Oct2022- upload

Source: Modern Machine Shop Source: Modern Machine Shop Source: Modern Machine Shop

Fig 8: Manifold maker Aidro increasingly Fig 9: Effective AM for production often will Fig 10: This is actually a picture of additive
makes its components through additive rely on workholding able to batch many parts manufacturing. A simple milling step is vital
manufacturing rather than by drilling for quick finish machining. Metal injection to AM via laser powder bed fusion: returning
intersecting holes into solid blocks. The molders are already accomplished at this. This build plates to precise flatness between
company 3D prints manifold parts using both photo was taken at Smith Metal Products, a builds. This milling step is part of the
LPBF and binder jetting. (Aidro is part of AM metal injection molder expanding into metal machining capabilities employed by 3D printed
technology provider Desktop Metal). additive manufacturing via binder jetting. implant maker Tangible Solutions.

close. 3D printing delivers near- needed, and also with precisely easily dozens or hundreds of
net-shape parts that are near the material needed to contain them could be 3D printed si-
to net shape indeed. Two im- those passages (an optimized multaneously in a single build. Another
plications of this are (1) the ad- form rather than a block). The challenge then becomes useful
vance of additive for metal part This is a potentially significant machining these parts, which production
production will call for greater development as well in terms of means engineering workhold- application
use of machine tools empha- the machining operations that ing to allow for efficient setup for metal
sizing precise multi-axis mo- will be important as additive in machining is a crucial ingre- additive
tion but not necessarily heavy manufacturing advances. Today, dient of success. manufac-
cutting, and (2) machining will drilling is the most commonly One type of manufacturer that turing,
increasingly focus on parts that performed machining operation. already has experience here not just
have a significant value already In a future in which additive is metal injection molders. powder bed
built in before they come to manufacturing for production is Users of MIM produce odd- fusion but
the machining. A part like the more prevalent, that might still shaped metal parts in high also binder
jetting,
one seen here is already near- be true. However, drilling and volume that are then in need is many
ly done, with hours or days of other machine tool holemaking of machining, so they are small odd-
3D printing to get to this point, operations will be directed to- already adept at custom work- shaped
plus heat treating. That means ward holes that need to be pre- holding and tactics for high-den- parts
the stakes of the final machin- cisely straight and round. Holes sity part setup on machining produced
ing operations and the impor- that need to be passages, poten- centers. Similar machining-re- at once in
tance of their being performed tially with a curving path and lated process engineering will a single
accurately become high indeed without regard to the precise come to be seen as an increas- build.
— much higher than they are shape of the passage, will more ingly common aspect of metal
with practically any other ma- often be 3D printed instead. additive manufacturing.
chined part.
6. AM for Production Relies on 7. A Basic Milling Step Is the
5. AM Replaces Drilling for Engineering of Workholding Beginning of Complex AM
Internal Channels (Fig 8) (Fig 9) Parts (Fig 10)
Some of the best candidates for Another useful production This point emphasizes an opera-
production via metal AM are application for metal additive tion mentioned in point 3 above,
parts that require internal fluid manufacturing, not just powder but it deserves further notice. It
flow. The previously mentioned bed fusion but also binder jet- is not just that metal 3D printed
adapter and small cutting tools ting, is many small odd-shaped parts are finished and brought to
are examples of this. Another is parts produced at once in a sin- final tolerance via machining. It
manifolds. Rather than drilling gle build. The ‘oddness’ tends to is also true that metal additive
holes from the part’s exterior so be a requirement, because very manufacturing in a sense begins
that they intersect to form man- square or simple parts would be with machining. Or at least, laser
ifold passages, AM offers the easier to machine than print. powder bed fusion metal AM be-
chance to 3D print parts with But if these organic-shaped or gins this way, because the plat-
precisely the internal passages complex parts are small enough, form for this 3D printing opera-

November-December 2022 | 21
www.mmindia.co.in