0:00welcome to another fight the laser
0:01learning lab um we focused last time on
0:06the lens no pun intended because the
0:11lens is actually the most important part
0:14of this machine I know that without the
0:17fiber laser itself it wouldn’t work but
0:19equally well you wouldn’t have to do
0:21anything with this machine without the
0:24ability to amplify the power through the
0:26lens so last time we checked out the
0:29focus on this machine and we now
0:31understand that we can if necessary use
0:34the focus as a mechanism for controlling
0:37the softness of the heat that we put
0:40down onto the surface it’s just one of
0:42the many parameters that we can play
0:44with to try and do this now that’s quite
0:48an important factor for today’s session
0:50because what we’re going to do today is
0:53something that I know can be done
0:55because I’ve heard and seen of other
0:57people doing it but I’ve got no idea how
1:00it’s done
1:00maybe they don’t either as an engineer I
1:04know quite a lot about some of the
1:06material processing that you have to do
1:08to get materials up to their finished
1:11state you know something I don’t have
1:13much in the way of to play with is clear
1:17anodized material because that’s the
1:20day’s challenge we’re going to try and
1:22find out if we can black mark clear
1:26anodized aluminium now technically where
1:29you think about it
1:29there’s nothing in there to cause it to
1:31go black we’ve got an aluminium sub
1:34structure there with a very thin layer
1:36of aluminium oxide sitting on the
1:38surface which has been created by an
1:40electrolytic process and then the micro
1:43granular structure which is being
1:45created by that process is then in field
1:47by assailant we have to look at the
1:50question and say well what is that
1:51sealant because whatever that salient is
1:54must be the thing that’s allowing us to
1:58make the mark black mm so I did a little
Transcript for Fiber Laser Marking – Black Marking Clear Anodizing (Cont…)
2:03bit of research and it turns out that
2:06the ceiling
2:08material that’s used for anodized is
2:11usually based on something called a
2:13nickel acetate formula we need to
2:16understand how to control the machine
2:19itself but the fundamental problems that
2:21we’re going to encounter all to do with
2:23materials and this is the first example
2:25we’ve got to understand what and how
2:28this material reacts the light so that
2:31we can apply the right sort of pulses to
2:33the surface to create what we’re after
2:36now the fact that it is a surface
2:40process means that probably we haven’t
2:44got to break through so we’re not going
2:46to be using powerful closes to pierce to
2:48pierce through the surface we’re somehow
2:50trying to get very accurate heating to
2:53the surface to modify the chemical
2:56they’re in some way so let’s just have a
2:59look a little bit further into the
3:00chemistry of what’s going on so we know
3:03that it was nickel acetate that was used
3:05there to create that final sealing
3:07process and here we got the data sheet
3:11for nickel acetate when I look further
3:14into the chemistry of nickel acetate
3:17toxic gases and vapors such as nickel
3:20carbonyl may be released when nickel
3:24acetate is heated it loses its water of
3:27crystallization and then decomposes to
3:30form nickel oxide okay so we’ve now
3:34gotta go hunting further what’s nickel
3:37oxide nickel monoxide is a green to
3:41black colored inorganic compound that
3:47then turns yellow and produces toxic
3:49gases upon heating so now we’ve got to
3:52decide the best parameters on this
3:54machine to create a very soft heating
3:58effect the point I’m really making it I
4:00could spend ages chasing around
Transcript for Fiber Laser Marking – Black Marking Clear Anodizing (Cont…)
4:01parameters but now what we’ve done we’ve
4:04narrowed down two things number one it’s
4:06a chemical process and number two it
4:08doesn’t require a great deal of e so we
4:10can now try softly T okay so here’s my
4:14almost my total stock of anodized
4:16aluminium it’s a piece of an angle
4:19which I then cut back into flat so
4:21they’re easy to work with and a piece of
4:24anodized aluminium – now from what I’ve
4:27seen there’s mainly only surface marking
4:30not depth cutting into the material
4:33looking at my parametric chart here I
4:36would suggest that we’re not going to
4:39start off down here look we’ve got lots
4:42of burning down here that means that
4:44although we’ve got a lot of range of
4:46pulse power across the top here that we
4:49could play with all of them down here at
4:51these low frequencies are very heavy
4:54burning what we need to do is go up the
4:57frequency scale and I know peak power is
5:02supposed to be at 850 I think if my
5:05memory serves me right two milliseconds
5:07two nanoseconds 850 is peak power why
5:11not use what are numbers I’ve got here
5:13which is a thousand and two nanoseconds
5:16so I think we’ll start off with that
5:19this is 500 millimeters a second well we
5:23could start off at that I don’t have a
5:26great deal of material to play with but
5:28what we’ll do we’ll draw a little square
5:30which is 4 millimeters square I will
5:33just put a fill in that line spacing
5:362.03 that’s basically half the width of
5:41the spot so we should get a 50% overlap
5:43on every spot we’ve got the loop count
5:46to one speed let’s try the 500 because
5:50we know that that’s roughly in the right
5:53sort of ballpark power hundred percent
5:56frequency a thousand kilohertz and pulse
6:00width – okay so at 6.15 not 6.25 so let
Transcript for Fiber Laser Marking – Black Marking Clear Anodizing (Cont…)
6:06me set the part height down here 6.15
6:14okay
6:22very dark gray as opposed to black every
6:25will slow it down a little bit give it a
6:27little bit more time to be tired
6:28here’s where my little chart comes in
6:30handy because we’re running this at 500
6:35millimeters a second
6:37so that means I’m producing 1700 pulses
6:43or 1700 dots per millimeter now if I
6:48change the speed to 200 or 250 look I
6:54can go from 1700 dots per millimeter to
6:57four thousand two hundred and fifty dots
7:00per millimeter so the heating effect
7:02will be greater if I run at 200
7:04millimeters a second now I’m going to
7:07note down all the data for this because
7:09I don’t want to lose this valuable data
7:11to be fair there probably looks to be no
7:21difference in the density of that black
7:23in this light it could be construed as
7:27gray it’s actually not bad it’s a pretty
7:31a pretty good matte black if I fail it
7:35with my fingernail there is just a small
7:40amount of depression in that cut well I
7:43did say that the material that we’re
7:45trying to blacken goes down into the
7:47material maybe that can maybe that
7:50counts for why we’ve got slightly very
7:52slightly gray so will now be a little
7:55bit brutal and we will reduce the power
7:57to 50%
8:00[Applause]
Transcript for Fiber Laser Marking – Black Marking Clear Anodizing (Cont…)
8:05the fingernail press tells you that
8:07we’ve got very little depression on the
8:10surface now I could definitely feel
8:12something there
8:16feel it here so let’s see how low you go
8:19is a power okay so we’re now gonna run
8:22this one at 20% power I think
8:34well it might be considered running
8:36before we can walk but hey I’m going to
8:40try scanning across a piece of Jew we’re
8:48looking at twenty three point three
8:50twenty three point three which is the
8:55maximum height and as it goes over the
8:57edge there it’s going to drop off so
8:59that’s actually going to test the focal
9:01accuracy of this process as well as we
9:05established in the previous session
9:06focus has got a very large range on it
9:09so we shouldn’t actually notice any
9:12effect at all as we go around this
9:14surface the focus is correct on the edge
9:17of the mark and it’s going to drop away
9:19by maybe one millimeter this does
9:21another check as well first of all we’ve
9:23got a different anodizing or we’ve got
9:25anodizing on a different type of
9:27material it shouldn’t make any
9:28difference
9:29but hey let’s see what we get definitely
9:35fifty material
9:39no this is not the F theta lens off the
9:43machine this is a macro lens I’m going
9:46to plug onto the front of this camera in
9:49the hope that you might be able to get
9:50some idea of what I’m seeing under the
9:52microscope
9:53now I managed to put this into some
9:55bright sunlight and the sunlight is over
9:58to the right-hand side of the camera and
10:01I think you’ll be able to see by virtue
Transcript for Fiber Laser Marking – Black Marking Clear Anodizing (Cont…)
10:04of the small shadows on the left hand
10:06side how raised up this surface is and
10:09how relatively speaking how rough it is
10:12so the first question is how do we
10:14reduce the surface temperature we’ve
10:17already got the power turned down to 20%
10:21we could go the other extreme and we’ll
10:24go right from 200 millimeters a second
10:26up to a thousand millimeters a second
10:29let’s try that because that means that
10:32we should be getting a lot less power
10:34five times less power per unit area now
10:43the one on the right is the second one
10:45that’s done a thousand millimeters a
10:47second and it does appear to be a
10:51slightly smoother finish and to be fair
10:54it does look to be slightly darker in
10:58this bright sunlight but when I look at
11:02it with the naked eye there really isn’t
11:03any difference so we’ve almost only got
11:07to turn the machine on or pick some
11:09lottery numbers and hey we’re going to
11:12make this material white knowing that
11:15I’m working on black marking of anodized
11:17aluminium notice later have been very
11:19helpful this morning and they sent me
11:21across their parameters for the black
11:24marking that they use let’s have a quick
11:28look loop one speed 400 power 42% that’s
11:35a bit exact frequency 825 Potts width –
11:40so they’re more or less using maximum
11:45power pulse like I am so their
11:48parameters
11:48not far off those that I was using for
11:51the first samples we tried on the tube
11:54first because I’m already set up for the
11:57correct focus height so we delete the
11:59Lotus Laser logo and we’ll just work
Transcript for Fiber Laser Marking – Black Marking Clear Anodizing (Cont…)
12:02with this little cue code after all my
12:04failures on this material let’s see how
12:07the Lotus Mart program works
12:32so here at 45 because a little bit slow
12:35on the stopwatch
12:59why the edge where it’s going out of
13:02focus we’ve got color so what I’m going
13:06to do now is to actually lift the focus
13:09up to see if we can bring that out of
13:12focus on to the top here to make it
13:14darker millimeter
13:16let’s try millimeter
13:27the fifties at the color very long its
13:29who play sthis you so I’ll increase the
13:32focus a bit more golf another elevator
13:36it is the localizable
13:40Oh
13:41start moving along here
13:48we’re gonna try those same settings
13:50right down the centre now
Transcript for Fiber Laser Marking – Black Marking Clear Anodizing (Cont…)
14:11there’s something different about that
14:12because I can feel your subducting that
14:15we’re now back to the Lotus later q-code
14:18settings
14:27apart from taking a long time
14:31none of those work we’ve now raised the
14:34focus hike up to 27 from its nominal 23
14:38point out that these are the Lotus Laser
14:42settings see we’ve got a lot less power
14:48there now because we’re using a lower
14:51part of the food
14:58not tucking into the surface and that
15:01looks pretty but whichever way I’ll
15:03catch it in the light let’s go back to
15:07my settings now
15:11so Tarragona doesn’t disappear I think I
15:14put more parity that’s looking more
15:18promising that is it cutting to the
15:20surface
15:24the answer is No so they’ve managed to
15:27get color five times the speed that the
15:31locust Llosa setting was so we’ve now
15:34change the line spacing to point zero
15:36one
15:45it’s got some quite nice text so most of
15:49that control is gained through messing
15:52around with the focus and softly not the
15:55power I found some more silver anodized
15:59aluminium from a job that I do for
Transcript for Fiber Laser Marking – Black Marking Clear Anodizing (Cont…)
16:01somebody else I have these as a surplus
16:04product now I’ve already done a little
16:06bit of experimentation because this is
16:08boring watching all this stuff for
16:10catchiest in the right light we’ve got
16:11black marks for some of them and as we
16:14turn it around some often go black and
16:17so off them go and disappear so they are
16:21light-sensitive this one at the bottom
16:24here was the first one that I did think
16:29it was that way up and that is the Lotus
16:34laser standard black marking it’s pretty
16:37good but then again that on there as the
16:43Lotus lasers standard black marking and
16:45it’s absolute rubbish the only
16:47difference is the position that I am at
16:50on the material as you can see some of
16:54these if we take a look here this has
16:57got a little black spot right on this
16:59corner but everywhere else it’s pretty
17:02dull and gray so from that I have to
17:04conclude that there’s a varying
17:06thickness across this surface in the
17:07anodizing that’s what we were finding
17:10with this product although it was
17:11anodized it was very very thin anodizing
17:15the thicker the anodizing the deeper
17:17these pores and the further into the
17:20material we can engrave and still hit
17:23this nickel acetate that certainly
17:26appears to be proving by these tests you
17:28know i’m now going to check what the
17:31anodizing is like on this outside
17:32surface here so if you catch them in the
17:34right light the difference between one
17:36and three isn’t all that great but one
17:41takes three minutes 45 and two and three
17:45take about 15 seconds
17:50now that works on this surface but of
17:53course it’s pretty rubbish on the bottom
17:58surface I mean this was the latest laser
17:59mark on the bottom surface and it’s
Transcript for Fiber Laser Marking – Black Marking Clear Anodizing (Cont…)
18:01lovely and black so I’m not I’m not
18:05arguing with that as a set of settings
18:07all I’m saying is it depends on the
18:10quality and the depth of the anodizing
18:12what you can actually do with it now you
18:15can clearly see the difference there now
18:17look I mean those marks hardly show at
18:19all but the locus layer mark settings as
18:23slow as it is it is durable no matter
18:27which way I fire the light at it I mean
18:31here we can clearly see that it makes
18:33the little or no difference as to which
18:36one of these that one is too weak but
18:38those these here were equally as good as
18:41this one which is the Lotus laser mark
18:45but we’ve also seen if we can get a
18:47fairly thick layer of anodizing then the
18:50nickel acetate penetrates into the
18:52surface deeply and even if we engrave
18:55away a small amount of the surface we
18:57still get this lovely black marking and
19:01we do this in something like about 15 or
19:0320 seconds whereas this one as I said is
19:06taking something like nearly about three
19:08and three-quarter minutes well I think
19:10we just have a quick 20 minutes sum up
19:12of what we’ve seen today sorry I’m
19:15joking um very quickly I think we’ve
19:18established that there is no one magic
19:21formula that gives us the opportunity to
19:24black mark on clear anodized aluminium
19:27we’ve established what the mechanism is
19:30and it’s a chemical mechanism of
19:32converting nickel acetate into nickel
19:35oxide and it only happens on the surface
19:38or to a depth that the nickel oxide can
19:41penetrate into the surface of the
19:43anodized material but what we’ve
19:45established is the region in which
19:47you’re going to have to work very very
19:49short pulses may be backed off with
19:52something like about 60 or 70 percent
19:55power and speed is not that important
19:59but I’ve been using speeds of around
Transcript for Fiber Laser Marking – Black Marking Clear Anodizing (Cont…)
20:01about two or three hundred millimeters a
20:03second but the most important thing and
20:05difference between my settings and those
20:09of Lotus later oh that Lotus later we’re
20:12using 1 micron line spacing and I’ve
20:14been using 30 micron line spacing so by
20:18default my speed is going to be
20:20substantially greater than their speed
20:22hence I can get to 15 seconds for one of
20:25those cue codes with the right material
20:27that I’m going to use for my product I
20:29might even be able to get it down to 10
20:31or even 5 seconds it really depends on
20:34the quality and thickness of the
20:36anodized aluminium that you’re using ok
20:38so it took 4 minutes not 20 minutes
20:41until the next time cheerio
20:44well I think you better settle down for
20:46another few minutes because I’ve got a
20:48little bit footnote to add to this video
20:50now a couple days ago I went to visit
20:52the guy that does my anodizing and I had
20:56a word with him about the chemicals he
20:58used for finishing off his product for
21:00sealing the anodized I often if he used
21:03at nickel acetate or no-mates is no no
21:07no no no that is it Regis use boiling
21:09water now boiling water is a process
21:12that can be used to seal anodized
21:16aluminium okay he’s only a small guy and
21:19he may be an exception but what he’s
21:22done he’s given me a little piece of
21:24material here that has been water
21:26boiling water sealed as opposed to
21:28nickel acetate sealed I’m wondering
21:31whether the weak results that we’re
21:32getting is because the product has not
21:34been finished with Anik acetate I know
21:37that this particular product has been
21:38boiling water soon so we’re going to
21:41give it a try with a few settings and
21:42see what we can find
21:44[Applause]
21:47so that gives us a shiny one
21:53something like discovered in my purse
21:55the colors
21:58there’s an interesting technique which
22:00I’m going to describe
Transcript for Fiber Laser Marking – Black Marking Clear Anodizing (Cont…)
22:01[Music]
22:07that’s it no I
22:09and so
22:15I’m getting yeah
22:21we confirmed it
22:30locate after a little bit of fiddling I
22:32think we found some results that work on
22:34this material there must be other
22:36chemicals in the surface of this oxide
22:40which are allowing it to turn black
22:43because this is quite a decent black
22:46mark and it must be just the thickness
22:50or the quality of the anodizing
22:52that’s caused the other problems the
22:54inconsistencies that we had in the other
22:56material but we’ll just test those same
22:58settings on the piece of angle that I
23:03had which was a good nice black mark
23:11[Applause]
23:28we’ll just test the same ku code on the
23:30piece of aluminium bracket that I had
23:41so there’s the time in the parameters
23:43for black marking clear anodized
23:45aluminium in some ways we’re still not
23:48all that close to absolutely finding out
23:51what that black mark is we don’t know
23:53whether this particular product has got
23:55nickel acetate in it we do know
23:58absolutely that this piece of clear
24:00anodized material has not got any nickel
Transcript for Fiber Laser Marking – Black Marking Clear Anodizing (Cont…)
24:03acetate in it and so where does the
24:06black mark come from on this one it can
24:08only be coming from some sort of
24:10alloying element within the aluminium
24:12itself now one of the candidates could
24:16be manganese there’s always somewhere in
24:19the reach of a half to one percent of
24:21manganese in aluminium alloy now my
24:25basic knowledge of chemistry and
24:27metallurgy suggests that that the mix of
24:31oxygen and manganese is a possibility
24:34because we’ve got the right ingredients
24:35on this machine eight oxygen in the air
24:39and after one percent manganese in the
24:42aluminium now although that surface does
24:45not feel in any way rough or ablated we
24:50won’t really be able to take a close
24:52look at that until I get my microscope
24:55so I think we’re going to have to leave
24:57this is a bit of an unanswered question
24:59I think the only conclusion we can come
25:02to is that we found a way of black
25:05marking clear anodized aluminium very
25:08quickly and now I’m really going to say
25:12goodbye to you and I’ll see you in the
25:14next session thanks for your time
