Energy consumption during milling of additively manufactured Mg WE43
UCARE AY21 presentation of research on the energy consumed during milling of additively manufactured magnesium WE43 alloy.
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- [00:00:01.830]Hi, my name is Preston Noll
- [00:00:03.210]this is the academic year 2021
UCare presentation from my project,
- [00:00:08.100]which has been energy consumption,
- [00:00:09.540]milling of WW43 magnesium alloy w so
- [00:00:14.600]first we'll go through
through a quick outline,
- [00:00:16.500]we'll start with the motivation
and the goal of the experiment.
- [00:00:18.890]Then the background of energy consumption
and a general overview of additive
- [00:00:22.850]manufacturing in general. Uh, the
research objective for this experiment,
- [00:00:26.420]some of the planning we've done
with the milling and print mapping,
- [00:00:29.150]a progress update, some literature
review, and then some more recent work.
- [00:00:32.960]So the motivation briefly
is overall the use of it.
- [00:00:37.160]Then a lot of the manufacturing can
create metal parts similar to what you can
- [00:00:41.030]do through normal metal manufacturing
processes with far less waste and far
- [00:00:45.950]greater accuracy and
control of your property.
- [00:00:48.130]So what we need to do to make these parts
usable is to characterize the material
- [00:00:52.190]and understand how the part would
behave throughout the entire structure,
- [00:00:55.970]which there aren't too many good ways
of doing for additively manufactured
- [00:01:00.230]parts. Right now, the best ways a CT,
which is expensive and cost prohibitive.
- [00:01:05.030]And what we want to do is locate in
defects within this part. And ideally,
- [00:01:09.710]we want to be able to do that without
destroying the part as you have to do now
- [00:01:13.790]to locate any defects through
milling and for future work.
- [00:01:17.630]The ideal application of this technology
is that you'll be able to use your
- [00:01:20.720]finished milling,
- [00:01:21.380]which is already a process that gets
applied to kind of perfect the parts that
- [00:01:25.400]come out of additive processes.
- [00:01:27.350]And we'll be able to use that and the
energy consumed during that process as a
- [00:01:31.100]process signal,
- [00:01:32.270]to understand the internal structures of
our parts and extrapolate the patterns
- [00:01:36.050]in this data to see if there are any
faults within the part that would need to
- [00:01:39.560]have it scrapped. So just some background,
- [00:01:43.160]there are three levels at which we're
analyzing the energy that comes out of
- [00:01:47.390]this optimistic machine here
that you can see in the top left,
- [00:01:49.910]which is the massive piece of machinery
that we use to produce in mill all of
- [00:01:54.500]our parts.
- [00:01:55.460]So you can see the power consumed
here at the machine tool level side,
- [00:01:58.760]a it's all the power being
consumed by the machine.
- [00:02:01.610]And then down to the spindle,
- [00:02:02.900]cuts out all the power needed to operate
the rest of the machinery and the
- [00:02:06.500]process level,
- [00:02:07.370]which is what we can use is
just the power that's being
- [00:02:12.350]put into the workpiece. As
you can see in the top, right?
- [00:02:14.990]And the tool removing material and this
power we can analyze and subtract the
- [00:02:19.280]difference between the cutting and air
cutting powers to really understand how
- [00:02:22.940]much energy is required to remove that
material and see any variation in that,
- [00:02:27.110]which could lead to us locating a
fault or any changes in properties.
- [00:02:31.640]So a little more background.
- [00:02:32.630]These are the equations we
use to calculate our specific
cutting energy is which
- [00:02:36.200]is what we can watch very as we move
through the part and the air cutting power
- [00:02:40.460]is our baseline on
either side of the park.
- [00:02:42.530]It's a little higher after we've finished,
- [00:02:44.180]which is a phenomenon we've observed
after you finish milling through a part,
- [00:02:47.900]the air cutting power's a little higher
than before you finish that milling
- [00:02:51.920]but we average it out and then subtract
that from your cutting energy to really
- [00:02:56.210]understand how much is being
used to remove material.
- [00:03:00.430]So the objective of this
research has been to
- [00:03:04.990]understand the energy consumption and
watch it vary between a continuous
- [00:03:09.910]print and a hybrid print.
- [00:03:11.110]So what we normally do is you spray
powder into the spot of a laser,
- [00:03:15.700]which melts this powder.
- [00:03:16.750]And that's how you create the part in
a similar way to what most people have
- [00:03:21.310]seen a regular 3d printer, but instead
of extruding a piece of plastic,
- [00:03:25.120]we spray powder into a laser and
solidify it in that melted pool.
- [00:03:30.250]Uh, we'll print normally
without any interruptions.
- [00:03:32.560]And then we also are going to introduce
laser painting treatments during the
- [00:03:36.370]printing of the part in order
to compress certain areas,
- [00:03:38.860]induce certain stresses and material
properties that we want to cause,
- [00:03:42.790]and then mill through them in
order to see if we can locate these
- [00:03:47.560]compressed areas and the properties
that they contain in order to understand
- [00:03:51.310]where a fault might be
as a similar signal,
- [00:03:54.340]or basically understand the properties
that we're inducing and show a way
- [00:03:59.110]to detect where they are.
- [00:04:01.750]So the planning that we've put out here
to understand that is we have to start
- [00:04:05.500]by constructing a tool where curve,
- [00:04:07.510]which will help us understand how
the cutting inserts that we use, uh,
- [00:04:12.100]affect the energy
consumed as they degrade.
- [00:04:15.280]Then we'll do some part printing with
some single tracks and density cubes being
- [00:04:18.580]our first kind of process verification
steps, then thin walls, which will,
- [00:04:23.140]that's our general part that we're going
to use for the milling and then hybrid
- [00:04:27.220]thin walls, which are the same as the
continuous ones that you'll see further,
- [00:04:30.310]sooner and or soon. Sorry. And,
- [00:04:33.910]but with that laser peening layer
included and then obviously milling of the
- [00:04:37.870]continuous and hybrid parts.
- [00:04:40.360]So first off the tool where analysis
we conduct using a scanning electron
- [00:04:43.450]microscope, as you can see here, these
are clean tools without anywhere on them,
- [00:04:47.080]from the flank and face, uh,
- [00:04:49.870]orientations in these
electron microscope photos.
- [00:04:52.420]And we use a software called
image J to analyze how much of
- [00:04:58.230]the flank and face respectively are
being worn down as the tools get used.
- [00:05:03.430]And that will correlate to an increase
in the energy required to remove
- [00:05:08.500]So we want to keep that increase to a
manageable and predictable place so that
- [00:05:12.220]we don't allow that to detract our data.
- [00:05:15.490]And then once we've developed
these to where profiles,
- [00:05:17.770]we can predict how much energy will be
added to our cutting energy as a result
- [00:05:22.090]of tool where and account for that.
So this here is our print map.
- [00:05:26.260]This is how we're planning
to lay out our samples.
- [00:05:28.180]Obviously these first six on the left
side are the continuous prints for
- [00:05:32.860]controls and continuous
prints. Peened on the surface,
- [00:05:35.320]which means we'll have a compressed
surface right at the top.
- [00:05:37.690]And those stresses will be induced at a
gradual level throughout the total part.
- [00:05:41.740]And then as a later step,
- [00:05:44.260]we'll have random samples
that are pained randomly at a
- [00:05:49.180]certain level throughout the part
sets of three painted each location.
- [00:05:52.390]And then these thermal match controls,
- [00:05:54.310]which is one of our important experimental
steps they'll be pulled out and sit
- [00:05:59.120]there while the hybrid samples are
pane so that they have a similar heat
- [00:06:02.750]transfer history as the regular
parts. So that they'll have,
- [00:06:06.140]there won't be any variation in micro
structure as a result of heat flowing in
- [00:06:11.060]and out of the part during
a construction process.
- [00:06:13.910]And then this is our cutting map.
- [00:06:15.110]This is how we'll be moving through these
thin wall parts that we've designed.
- [00:06:19.040]Uh, there'll be about 150 micron or a 0.1,
- [00:06:23.030]five millimeter depth of
cuts or milling off a very,
- [00:06:26.120]very slight amount of material because
we don't want to miss one of those
- [00:06:29.120]compressed layers because there
will be somewhere into a 20 to
- [00:06:34.010]50 micron compression of the material.
- [00:06:37.040]And then about a millimeter's worth of
depth where you can actually see the
- [00:06:41.540]effects below,
- [00:06:43.160]but this is pretty easily missed when
you know these tiny little parts.
- [00:06:47.180]So we have to give ourselves a little
bit of opportunity to notice that that
- [00:06:50.930]compressed layers there. And then
these are the rest of our dimensions.
- [00:06:56.330]Uh, some current progress
we've in research done by
my colleagues, Sam or geese.
- [00:07:00.800]Uh, he's also presenting this year.
- [00:07:02.270]We developed through the print
parameters for ma or printing magnesium
- [00:07:07.550]on this machinery, which is groundbreaking
by itself. We did some density cubes,
- [00:07:12.170]which showed us the adhesion issues we
were going to have in printing magnesium
- [00:07:16.640]onto sandblasted magnesium
plates. And like it says here,
- [00:07:20.060]if the cutting forces during milling
approach the fracture strength of the
- [00:07:23.270]interface between the
part and the build plate,
- [00:07:25.550]we might launch the part off the build
plate while missing will while milling
- [00:07:29.900]rather, which is extremely hazardous.
- [00:07:32.300]So some research went into existing
processes with magnesium, welding,
- [00:07:37.160]and additive manufacturing,
- [00:07:38.240]which found that lowering the laser
scan speed cleaning with ethanol and
- [00:07:42.140]the base plate would all be helpful in
removing these difficulties in adhesion.
- [00:07:45.890]So some of the obstacles we've faced
lately are the material hazard drink
- [00:07:49.760]which magnesium is impossible to print
met is at additive manufacturing process
- [00:07:54.290]and dangerous to mill without being in
an inert atmosphere, which we use argon,
- [00:07:59.060]which there are some cutting conditions
which do support dry milling without a
- [00:08:02.630]fire hazard.
- [00:08:03.560]But we have yet to establish that
criteria and get to a point where
- [00:08:08.420]we're safe to mill parts
without inducing an atmosphere,
- [00:08:12.320]which we want to do as little as
possible because it's extremely costly.
- [00:08:15.410]And some machinery upgrades and repairs
have slowed us down lately where some
- [00:08:18.680]water was introduced
into the build chamber,
- [00:08:20.540]which if you know
anything about magnesium,
- [00:08:22.370]it reacts strongly with
water and creates hydrogen,
- [00:08:25.220]which does not react well
to being hit with a laser.
- [00:08:28.130]So that's obviously a threat and the
ongoing installation of the laser
- [00:08:32.870]peening equipment is going to enable
our later experimental steps with the
- [00:08:36.230]hybrid parts, but has also delayed
their construction. So finally,
- [00:08:39.830]the ongoing and future work we're working
on the construction of the tool curve
- [00:08:43.640]right now, milling rod KZ 68 alloy,
- [00:08:46.010]which is very similar in the relevant
material properties to WB 43 and far more
- [00:08:50.750]readily available. And once we
understand that tool where progression,
- [00:08:54.140]like I mentioned earlier,
we're going to can, uh,
- [00:08:56.490]condition our cutting
inserts into that flat range,
- [00:08:59.310]where we can predict the effects of the
tool where then obviously printing our
- [00:09:03.540]continuous thermal matched and hybrid
parts and milling through them is our end
- [00:09:08.430]stage work for this experiment.
- [00:09:10.290]And what we can see here on the right
is a energy density map constructed of
- [00:09:15.240]previous stainless steel samples
that we had done in previous years.
- [00:09:19.170]And this is the kind of heat map of
energy density that we're going to be
- [00:09:22.380]looking at with obviously red, being
harder to mill and green being easier.
- [00:09:26.100]This is the kind of outcome we're
looking for of the end stages of this
- [00:09:30.240]And hopefully soon we'll be progressing
to the stage where we can create these
- [00:09:33.570]heat maps and really describe how these
magnesium parts are reacting to our
- [00:09:38.520]hybrid conditions and what they show
us as we mill through them and the
- [00:09:43.410]impacts of this energy
assumption data. So I,
- [00:09:47.630]and I thank you for listening and thank
you to my primary investigator, Dr.
- [00:09:51.200]Seeley in the mechanical engineering
department for all of his support
- [00:09:55.220]throughout this project.
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