ColdWorking Lab Prep

0:00okay Professor Lou is here and we're going to be talking about what you're going to do in this lab there's a lot of steps that you're going to have to do so the first thing is you're probably going to get seven to eight samples of brass handed to you and they are going to be in the process condition of what we

0:15received them as so we're going to do what we call an anneal and we're going to anneal these samples so that we've turned the crystalline structure to their natural state if you want to think of it like that and then what we're going to do is we're going to go over to the shimatsu's and we're going to

0:28compress these at a set load per this lab sheet we're going to be recording the diameter the length and the hardnesses at each interval now the what we're going to do next is we're going to take and cut some of these samples okay you're going to take one that's annealed and one that's been maximally compressed that's cool work and when you do that

0:48need to make sure you pay attention when you cut your samples out as to how you loaded it because that's going to tell us we've maybe loaded it in this direction we expect things to be compressed in this direction and so we're going to go to the saw metallurgical saw cut that then we're going to take the two samples and we're

1:04going to mount them in little pucks we're going to polish and etch them using some of the machines behind me we're going to put acids on them and then go over and and use the microscopes and we're going to complete the lab with measuring the grain sizes of these samples that we talked about in lecture so I hope this helps and let's go start

1:22the lab okay we are now at the furnace and I'm going to be doing an anneal on some brass pieces here and what you want to do is put your parts inside the tray on this little ceramic piece and we're going to pick them up and load them into the furnace now when we get into this furnace when you talk about safety you

1:40have to have a fireproof retardant um lab coat on I have one on you can tell it's a nice blue color the other thing of safety gear you're going to have to have are the thick gloves that look like this don't get welding gloves or anything out you need this glove this is a high temp glove for over 2000

1:58degrees because that's going to be very hot now I'm only going to go to 700 degrees Celsius I have it turned on and it's set at the temperature so I'm going to verify my temperature is there and I'm going to come in here put my glove on and I'm now tooled up and ready to go now we're going to use these tongs and

2:18you want to be careful with these because these are going to get hot as well and so when we get done we want to lay them onto the refractory material right here and not the counter so I'm going to open it up and I'm going to reach my part I'm going to get it and stack it in there now don't touch

2:33the side coils inside of the furnace with the tongue it's going to put your parts in there you might want to put on the middle portion of the furnace and you're going to slowly close this door securely and you're going to start the time on your part as to how long it needs to be in there for me it's going

2:47to be about 10 to 15 minutes the other thing I have here is this nice little tool to tell the temperature and I want to talk about safety what you can do is it should be set on Fahrenheit that's Fahrenheit so 700 degrees it's going to be around 1200 degrees Fahrenheit I can shoot in there and see my part getting

3:03hot if I ever have a part down here on the quench table and it looks and I'm going to let it sit there I'm going to shoot the part and see if it's hot before I touch it again don't ever reach down and touch apart your tendency is to Crunch and tighten up on the part when you do it use this tool to discover if

3:18it's hot or not we also have a tank of water right here and what we can do is take some of that water and splash it on the part and see if it sizzles if it doesn't and the water stays on top of the part and doesn't boil away then the parts probably cool rules so don't use

3:31your hand as a temperature probe now in our quench Medias we have a tank for water and a tank for oil brass we're going to use the water well and I'm going to open this up just to see what my temperature looks like and I'm going to shoot in there and I'm at 12.50 right now so I know I'm at 700

3:55degrees Celsius you may have to do some conversions you guys have phones ask Siri she'll help you out what I'm going to do is take my samples out and put them in water now there's a little rack down in the bottom of that that looks like this that's going to keep the samples from touching the bottom of the

4:10pan and not cooling evenly all the way around so I'm going to open this up and I'm going to grab one part out at a time and I'm going to drop it in the water and just let it go and I can sit there and watch it cool so I just quenched my samples in water and hopefully they're

4:26cool now so maybe I can go in there and get them out now at this point I'm going to roll my sleeve up so I don't get the sleeves wet and I'm going fishing now if they've been in the water for a little bit they're going to be cool and I'm going to set them out up here

4:42and again people might come by and see my part sitting on there and not know if they're hot or cold again what can they do they can come in here now I wouldn't trust the temperature probe here all the way but it says it's at 70 degrees I can take some water splash on the part the water stays on there and it is cool so

4:59at that point we know we can pick it up so anytime you see metal parts around this area or even up in here you need to make sure that you do the water test and the temperature test both before you touch the sample we've just annealed our samples out and we have a variety of samples that we're going to be testing

5:16per lab sheet we're going to be doing that on the shimatsu's now some of you are going to use the larger shimatsu and some of you guys are going to use the smaller shimatsus the only difference in the two machines other than the capacity is we're probably going to notice there's going to be a difference in the

5:30controls on this machine we're going to have to hit manual and we can jog it up or down right here if you're using the smaller shimatsu then what you're going to do is you're gonna have a different control panel that doesn't come off and we have a jog mode right here and you can jog it up or down down using these

5:45commands now in the future I'm going to get you guys a screen capture where I can screen capture right now I'm sorry but I'm going to record the screen and kind of Step you through the controller what we're going to do is go up here to transpesium and open this up and when we go into transposium it's going to want

6:00to know what the user is and your user and the password is user this is the software trapezium that's going to run the shimatsu's both machines are going to have the same software so once we're in transposium we have what we call test methods and a test method is right here and that is going if I click on that

6:18that is going to open up what kind of procedure do we want to do for this and you guys in this class doing your brass pieces we're going to use the engineering science 3311s and we have different cold work profiles and this is going to be on both of the shimatsu's and you're going to identify which load

6:33you want to run so we're going to have to run each method for each load setting that we have so I'm going to start off with the 7 000 pound load setting right here and I'm going to say finish when I'd hit finish it's going to open up and it's going to be ready to start the test so at this

6:50point we're going to go over and load our sample soon we're going to be loading our sample inside of here what we're going to do is load our sample in the very center here and we're going to push it up in there put it to the center and what we're going to do is lower this top portion down to the sample and we're

7:04going to do that with the controller here and you want to be in manual mode so there it's in manual mode there it's off we're going to put it in manual mode carefully jog that down to where it's just right above the part and I'm gonna stop I've got a little bit of a gap if you do hit the sample I've

7:20got it set up where it will stop and it won't hurt the sample once we get done take off manual mode and let's go test this thing the last thing we need to do we put our teach pin it back up in manual mode is turned off we need to shut the doors be sure to close the left

7:35door completely and then the right door completely if you do it in the opposite directions it won't trip the switches and the Machine will air out on you just loaded or sampled and if there's any error messages that come up just hit reset because more than likely we have the controller in manual mode or we have the doors open we're

7:54going to reset the machine before we conduct the test and we're going to come up here and right click on force and say to zero you don't need to calibrate because we've already calibrated the machine for you come in here to stroke and we zero that out so both of these are now zero we're now ready to come in here and start our

8:10test now when we start the test it's going to say check testing make sure everything's in position we've done all that and we can start the test and now it's loading because it made contact with the part and it is going to go up to the 7 000 pounds holds it for three seconds and then it's off now you're

8:26going to go hey I lost my load because if we keep the load on there if we go past the yield then the part just keeps deforming because you've gone past the yield just got our sample out of the machine and what you guys are going to do is measure the diameter the length and you're going to notice that the

8:41diameter on the ends do not go out like the middle portion will do measure in the center on the diameter the reason is the friction between the top and the tooling keeps this side from actually changing so use for your true stresses the area the diameter Associated to the mid section there you're going to take hardness values on the top of these on

9:02the machine on the hardness tester and then record all that in your data sheet to go from the test of 7 000 pounds we want to go to the next one we're going to come up here to file up here we're going to come out the file and then we're going to cursor down to return home what that's going to do is bring us back

9:19and we're not going to save this file because we don't need to save anything other than recording that we did the test we're going to select a new method we're going to scroll down here to the 9000 pounds and we're going to repeat the test we're going to do this for every sample we're going to be talking

9:35about how to cut our metal samples now this is the fine automated cutting machine from Struthers that we're going to be using and if we look at this the first thing we want to talk about is the wheel that's on the machine now this wheel is very very very fragile so if you touch it or damage it let us know so

9:53we can get that thing replaced this machine does have a controller on it that's going to have methods and we're going to use method a for the majority of our cutting that's going to dictate the distance of travel the speed all those things that we're going to have for our materials we do have an automated hand wheel right

10:12here that if you it's kind of like a joystick if you push it it's going to move the Vise in and out and what we want to do is make sure that we don't touch the blade the cutting wheel to our part because it will break it and it is a variable speed so you might before you load anything in

10:31there get used to using the machine the other thing we have over here is a emergency stop anything happens just hit that we do have a red button that stops the program and a green one that will start the method let's talk about how do we plan our Cuts this was a round sample that we took and applied compression to

10:53and it barreled out some and we want to be able to see that so we've cut this in half where we can see the grain structure in that structure right there we wouldn't want to come in here and make a cut off of the end and look at this because it's not going to be as interesting if we look at the cross

11:08section cutting it this way so make sure you understand what you want to see in your cuts and make sure you're cutting them properly now what we're going to do is load our part into the Vise now this Vise has a clamp that will lock down so if you push this down it will lock onto the part there so you want to raise it

11:26up and then you can pull this plunger back and forth to hold your part and then when you get it held just lock it into place so the next thing I want to do is come in here and cut a little bit off of my part so I'm going to put it in the vise extend it out past what I want to have

11:43cut off I'm going to push two and lock it down so we're ready to cut our part we're going to move the machine while we can see it with the door open real easy up to the point where we're fairly close to the part we're going to shut the lid we're in method a we're going to hit run

12:03and the machine's going to cut her apart and you're going to need to watch when that part is cut so you can hit stop and to do that we're going to hit the stop button right here now we're using fluid and a real thin curve so that we don't metallurgically change the material in the cut now I saw my part move someone

12:19hit stop when I do you just need to wait and I heard the machine down here click and it relief release the safety latch until that latch is open and then you can open it up so if it doesn't unlatch just hit the stop two or three times it will let you open it up and I can see my

12:36part is way back there so I'm going to be very careful in reaching in and getting that part so I don't hit the blade the next thing I need to do is remove my part and I find the best thing to do is retract the blade the cutting wheel from the part area unlock it pull this back and

12:52then reach in real careful and I have my part so that hopefully helps you learn how to cut a sample and have it ready to go over and polish an edge so this is the machine that we're going to be using for making our pucks now the machine is on and if we need to come in here we can hit Escape that'll

13:09take us to our main menu and there's a menu called processes extensions configuration Services all you need to do is push down on this and go to processes you can change your selection by that wheel anytime you don't know where you're at just hit escape and it'll bring you out of the menus so I'm going to go back into

13:27process there the only other controls we really need to talk about are going to be these controls right here one and two refers to one and two so our left and right then we have an up or down on these yellows if you push that down whichever one you have selected will lower down the little table right

13:45here and so I need them raised up at this point so I can load the samples the other thing we have is start and stop that's going to start the process and this tells all the process that we're going to have in terms of how many minutes what temperature and what pressure we're going to have to making

14:00that Puck and you don't have to program this this is all set up for the resins that we have which brings us to the fact that we have three different kinds of resins we have black red and green now what is this resin this is a phenolic it's called Bakelite okay I'm now ready to load my parts in and I have cut my

14:18samples and initially I had my compressed sample fairly tall and I cut a piece off so that I could have a small piece now I need to remember how I can press this I compressed it in this direction and that's nice because it's almost a diameter and it's going to be compressed I don't need a big piece because I need

14:35to put it inside here I'm going to mount that in the center of where my Puck is going to be again these are the little platforms I'm going to put my round piece over here on this one now at this point we're ready to lower the machine down so I'm going to change it over to number one first

14:50and then I'm going to tell it to lower now it's lowering the part down into the machine at this time I'm going to take the funnel so I'm going to put this up here and I'm going to go get my resin you notice I've got my resin right there and I'm going to pour them into the machine

15:09so this is going to be kind of green representing that it's new and fresh and all I've got to do is hit the start button there what we're going to do is open up the top by unscrewing this and it pops and it's not going to lift off so what we're going to do is go over and hit the

15:30selector to activate which side we're on and then hit the up arrow and it's going to bring the part up so we can get it out and here's our part and if you look you can see the part is in the puck at this point I have my nailed sample

15:50and my compressed sample and I can tell which direction I compressed by the way I orientated it in the puck so what we're going to be doing is mounting our Puck into the carousel that gets used by the polishers we're going to slide the puck up in there and it is going to fall out when

16:11we lift up the carousel so we have O-rings back there that we're going to put on our part about Midway so it kind of helps if you just kind of pinch it up there and not just roll it on there but get it located on the part securely and that's going to be a retainer to keep it from falling

16:34then you can take the puck and put it in the hole in the Carousel and it'll be retained I just put in my second part and if you notice I put it Opposite each other so that when it's pressing down it's equally supported on each side okay once we have our samples loaded into the carousel we need to talk about getting

16:54it loaded into the machine and the best way to do that so put it up here push this bottom button here and it's going to hold that so it is now locked in now we can move this head left or right and we can also raise or lower by hitting the yellow button with the up and down

17:10arrows so we're going to raise it up we're going to move it out of the way we're going to talk about the consumables on the other side now I'm going to be doing brass and when I go to the methods it's going to tell me which Wheels I need to put what pads I need to put down here so I'm going to make sure

17:25this is clean right here and the first one I'm going to need for that is going to be the foil and it's going to have that on here in terms of the foil and it's also going to have written on there that it is for brass and for aluminum as a reminder so if this gets damaged or

17:40worn out typically this so only these foils will last for maybe three runs and then the Tas or I will replace this for you so we have multiple of these sitting out so get the one that looks the newest if you can until we replace that the other thing that this one is going to need is going to be the MD Largo and

17:58that's again for brass and this is going to be the second stage on this machine now we're doing a grinding operation on this machine the other machine is going to be used for doing the polishing of this and the other thing we want to talk about the machine is we have bottles back here that have suspended diamond in

18:15compound in a liquid and it's going to be pumped through the tubes as we need it it also is going to apply water for so it's pretty much automated the only thing we're going to have to do is move this out of the way come in and put our pad on the machine and I know that it's

18:30going to want this foil so I'm going to center it up where it looks like it's centered up on the machine I'm going to bring this back over so let's talk about how we use the controller I'm going to go ahead and lower this down here so maybe we can see it on the video a little bit

18:44and on the controller you're going to hit return return that's going to take you to the main menu you're going to be able to go through the menu by turning the wheel and you're going to select single specimen methods we're going to hit the button just by pushing that round black button and now we can scroll through which method we want and I want

19:01brass grind so I'm going to select that and it tells me on there the two steps that it's going to take to do this grinding operation the first one wants that foil which we just put on and it tells me how it's going to run so if I was to come in here and just hit the green button right here

19:18it's going to be ready to run that and it's going to start running as feet lower down when it started and in the program it tells how much to hold the sample down into the abrasive down there and so we're turning the wheel as well as we're turning the samples and it's going to run for two minutes now the

19:36liquid that we're seeing put out here the water is being recycled it's being captured underneath in a tank filtered and reused okay the machine just finished and what I'm going to do is go ahead and interrupt the operation you can see the little feet coming up there and I'm going to take this off you do not need

19:53to take this off in your procedure I just want to show you that on the bottom we now have nice shinier looking samples and so that first grind is really taking effect and I'm going to put this back up on there so again you don't need to do this because we're going to leave the samples in the machine for each test the

20:11next thing we need to do is carefully lift up and make sure you don't lift the pad off of the main frame this is called a gecko pad and we actually put different foils on that pad so be real careful not to grab the black piece off of that gecko pad so one of the things we need to do is to rinse this off and

20:30we have a sink over there by the door and you can take it over there and just rinse it off okay I'm back from rinsing that off I'm going to put it back into where I found it and looking at the program it wants the MD Largo on there and I have that consumable again I'm going to come in

20:47here and it's probably easier to move the head over and then you have room for your fingers here and we're going to put that pad where it's centered up on the machine now we're going to bring that machine in and we're going to run that next step and we're going to say okay it says the head was not lowered so I'm

21:02going to lower the head following the directions now I can come in there and run that sample and the pads are going down to hold the samples now let's talk about what's happening here you're going to see a lot of material coming out and that's coming from the pump here from the bottles and so we're putting on

21:20some Diamond Compound on there so the machine just finished and what I'm going to do is go ahead and raise up my head and I'm going to remove this wheel this grinding pad I'm going to take that over to the sink and rinse it off as well now when I rinse it off I don't have to get

21:38all the black off here I just need to rinse off the bulk of it and then I can set it back in the rack now at this point we're ready to take our parts and go to the next process we're gonna be able to come in here and press the button and remove our samples and take them over the next the next

21:53stage of final polishing now we've mounted our samples up in the machine again we're going to be able to move the head out of the way now doing brass on here if I go to the machine again I can go all the way to return return and go up here I'm going to lower this down so I can see the screen here a little bit

22:10again I can come in here and hit return return go to the main menu we're going to do single method methods here and we're going to select brass polish so this is going to be our polishing on the first stage we did the foil grind followed by the 9 Micron Diamond polish and now what we're going to do is we're

22:29going to use a three Micron compound coming through the system but it's going to want the MD moles so what I've got here it looks like we got a brand new one there's the Duro I'm looking for the mole and it looks like yes we do have a new one right here for brass and so this is kind of like a fabric material that

22:48is going to put the compound on and polish up our sample so again I'm going to put that on the machine where it's centered up and that looks good we've got that centered up we have our samples mounted I'm going to move the head into play we're going to lower it and then we're going to come in here and

23:05start that operation again the little feet come down putting the pressure on the sample and it is now pumping as you can tell in the back you can hear the little pumps it's starting to put the initial material on there and then it will drip the material in there as it's needed we're gonna let this run for two minutes

23:21now being a new pad and it was dry I'm going to add a little water to it just so that it helps keep the friction level down again we have little bottles of water just want to put enough on there and it'll help it get started the machine just finished so I'm going to raise the head up we're gonna have to

23:37change our wheel out so I'm going to take this over and just rinse it off as well I just finished rinsing it off and I'm going to put it back in the tray and it looks like the next wheel we're going to need is going to be an MD Kim and this is an MD Kim and it's an oxide polishing wheel that

23:56we're going to use so we're going to be putting oxide polishing compounds on these now unfortunately the machine does not do the oxide polishing compounds automatically because it will clog the lines as it dries when we're not using it so we have it set up here on the side in a bottle so we're going to be using

24:12the Ops for this material and that's if we're going to come in there and just get it to barely drip on there so what we're going to do is move this stand up here into the machine because centrifugal force is going to sling the compound out to the center and if you notice we were dropping our compound

24:29about here so we want to get that properly located so what we're going to do is come in here and we're going to open this up and this is kind of a dry wheel right now it hasn't been used so I'm going to put a bit of water on there and I'm going to come in here and open

24:42the valve on the bottom ever so slightly where I can get a drip now this has a little bit of water left over because we just cleaned it but hey there's the white stuff I need so what I want to do is just have it dripping about that speed right there so you can see my drops kind of dropping there

24:59coming out so one two three four so about every Force counts you want to drop coming off what we're going to do is come in here and hit start it's going to say hey lower that head we're going to lower the head down and then we're going to come in here and run that for five minutes now this is

25:17the final polishing that we're going to do before we go etch every minute you want to that it runs come in there and spray a little bit of water on there to help reduce the friction and the heat generated and help that Polishing Compound out a little bit okay the machine just finished and what I'm going to do is go ahead and raise the head up

25:34and move it over to the side and again I'm going to pull my pad up and I'm going to take over and just rinse it off and bring it back to dry now I'm ready to take my parts and if we notice the parts are really looking nice and shiny like mirrors and we have a lot of swarf or residual stuff on this

25:54Carousel so that's going to take us to our next stage let's wash it so we're at the washing machine yes we have a washing machine for you guys there's a black ring up above once you get the holes lined up pull it down and it will click into place hold in your samples and then what we're going to do is come

26:09in here and we're going to select which type of washing we want I would like the full wash job on this one so it's going to close it's all automated and it's going to come out clean and dry as you can tell the machine opened up when it's finished and so we have let's reach up here push that black portion up there

26:29down it'll release your samples for you so at this point we have our samples and I'm going to take them out here and they are now polished up and they look like mirrors they're really really shiny this is going to be ready for etching now take this and put it back over on the rough grinding machine next to it so the next

26:49group can use it also take your O-rings off and return those I would keep from touching the brass samples or whatever sample you're going to have because you might introduce corrosion or artifacts into the imagery that you're going to take so handle the puck on the outside so we just finished polishing our samples and now it's time to etch the

27:08samples so what is etching going to do etching is going to let us see different grains in the sample the acids will eat different regions or phases of the sample revealing those grains so the way we're going to have to do this is we're going to look back on the back wall and it tells us which etchant is for which

27:25material and so it says back there copper and stainless steel weld inspection we're going to use a phoretic chloride now this is a large bottle of that material and it's going to be kept down below what we've done is put small amounts of that in smaller bottles for us to use and we want to practice safety in

27:46dealing with these acids so we're dealing with the vent Hood again don't raise it all the way up the alarm is going to go off you need to have it down to working height that it's still pulling air through here and you can hear the alarm going off if you have it up too high so I can see my samples I can see what

28:01I'm going to do I'm going to take a Q-tip right here and I'm going to open up my sample and so I'll see the other acids back there for different Metals I'm going to go ahead and open this up and again another safety item is gloves we're touching all these acids doing this stuff we have boxes of gloves over on the other side

28:22and all different sizes for you it's not an option it's required to wear gloves I'm going to get my Q-tip wet and the trick is to come in here and rub the sample turning the Q-tip and it is going to introduce new etchant to the part and we're going to let it eat on that brass alloy that we

28:43had there now it's pretty shiny right now and the way I can tell if it's etched in there or not is by the fact that it will start dulling out a little bit in luster and color and so you can tell it's going to take some time now I can see it's starting to work I can see it becoming Frosty and

28:58what I'm going to do at this time is dispose of my tool there and I'm going to reach back here with the methanol and rinse my part off getting rid of that acid okay methanol is going to feel cool so you're going to feel that coolness in your hand through the glove and my sample is not near as shiny it's a

29:18little cloudier I'm going to be able to find a region on here and take a microstructure analysis of that so let's do the other sample here and so let's talk about the microscope first and then we'll go to the computer and how it works with the microscope now this is a typical microscope and the sense that you can look through the lenses here and

29:35see what's going on or we have a prism that divides off and it goes to a camera over here and we can take that camera image and see it on the screen so we should have a green light on the camera and over here indicating that it's on we have a rough Focus here with a fine focus these two knobs will move

29:53the table X and Y Direction so we can scan across the material and see what's going on now one of the things I want to point out in this is the microscope the image that I'm going to see in here in the lenses here will be 90 degrees out of phase over here on the camera so if

30:08I'm going to take a sample like this that has been compressed in a certain direction right here then what I'm going to do is set it on the machine like this and when I look at so the compression force directions are this way so when I see the image on the screen it'll look like it's looking like that so you may

30:25need to think about the orientation of how you put your sample on that surface up here and this is where you're going to be putting your sample and you're going to want to have the visible portion of the sample located right there okay make sure you're not looking at the Bakelite but the part that you're going to see let's look at this

30:42microscope from underneath my recommendation is to have the lenses brought all the way down some of the lenses have multiple focal points and if you start up high and focus it and then you switch to the lenses that have that issue you're going to see the lenses interfere and hit the base of the machine so bring it down to the bottom

31:01get to the five power or the 10 power focus in at the very place where it gets in focus and now you're probably at a point that you're gonna be able to change the linges all the way up to 100 power okay let's talk about the computer side of the system now when you guys come in here you're going to see some

31:16folders at the top and those folders relate to your class that you're in and each semester we create folders for you and inside that folder you can go in there and create subfolders for the different groups that you're going to be a part of and you can capture your images to that folder I recommend doing this and then copying that folder over

31:34to your flash drive leave them on the system right here so if you lose your flash drive or the files become corrupt you have these captured and you don't have to redo the experience tournament or lose your data and we're going to open up NIS now again we've got the green light on the microscope and it's on and this is going to bring up the

31:53elements program for Nikon okay so we're now into the Nikon system and to capture the image on our system we're going to hit the little green play Arrow up here the live button we're going to go live and we're going to be able to see what the camera's seeing and again if we need to change the focus we

32:11can fine tune and adjust our Focus we can move the image left or right in the system one last thing I want to point out on the microscope is that we can change the intensity of what we're seeing on the screen so if it's not showing up you might change over here on the microscope the intensity of the bulb

32:28and the light that we're going to illuminate the surface so this is looking like a pretty nice surface for this structure now again I'm starting with the five power here and the 10 power those are great powers to focus on and again you want to start with the lenses all the way down come up to those and

32:46then focus them and you have Minor Adjustments that you're gonna have to be in there now this is a really broad showing the equest crystals that we have going on here and we're not getting a lot of detail but a good over uh overview feeling of the that the repetitive consistent looking structures and then we're going to increase our

33:04magnification here now one of the things I want to talk about is when we change the magnifications on the microscope we need to come up here on the nose pieces and we need to manually change what is the lens that we're using to match the nose piece so right now I'm at 10 and I want to want to change that to 10.

33:21that's going to bring us to our next feature in the software we're going to be able to use the measurement tools here some if I just wanted to draw a line across something let's say from right here to over here I can see that at the line is 0.55 micro inches there's also that scale down here and to turn that on and off we can come

33:41over here to right here to the little micro meter scale turn that on and that's going to have a line representing what is a micrometer set to this scale for the nose piece and the computer software all meeting up now if I change that nose piece I want you to notice the length of the line changed so I'm going

34:00to get bad data if I capture that have the wrong nose piece selected and save that image so I want to make sure I have the right nose piece attached to whatever lens I'm using when I'm capturing image now in your lab you're going to be measuring grain length so you need to measure a line that's going

34:17to be a great way plus you're going to want to have this on where you can see a line and we can take these images into Microsoft Paint later on and we can actually draw a line and kind of prorate that out for the Line crossing the number of grains that we're going to have to do our grain count for the grain

34:32size standard that we're going to be following and then we likewise we could draw a line vertical relative to that and capture a square and capture how many grains are in that square now again each grain if I look at it I'm going to go ahead and boot up to one power bigger here so that we can kind of see the

34:49grains a little bit more in detail so I'm going to the 20 power and I'm going to change that I can now count the grains better so 20 power is going to be a really good tool for you to come in and count your grains probably on this brass exercise now some of these things are different phases of

35:06grains and we're also seeing different alignments of grains at different angles there now this is what you're going to want to do in your lab is probably get to a magnification where you can see the grains really clear draw your lines multiple lines count those grains again you don't want to go over the same areas you probably want to draw a line up here

35:23draw a line down here so that you can get an average of the grains do three lines take the average of those we now have our image we have the scale if I want to capture that and save it so let's say we want to come in here and measure the length of those grains I can come in here and draw a line from here

35:42to here so if I want to capture this image and save it I can come up here and say save as and it's going to save it as a JPEG format right here and I can direct it to my course folder have a subfolder in there and save that now again when I save that I may want to

35:59save that image in terms of what the alloy is the process condition and maybe even did I you do it on 20x power or 10x power or 100. now if I go over here to the computer and I open up that folder I now have that okay we're at the end of the lab just about I mean you guys have

36:18made pucks you've annealed materials you've cold work materials you've learned how to polish and etch remember how to use the microscope I don't have time for you to do all that to another material you guys are going to get out of here and use a lot of Steel in life and so what I have for you is

36:38a piece of 1018 still now I'm going to have this out for you guys to look at so you can just kind of touch it and fill it a little bit and you're going to see that it has a really nice surface it's free of meal scale okay so this is done it's 10 18 still that means it's a

36:53low carbon steel very very low carbon we're going to see mainly ferrite in its structure white structures with occasional little black things called perlite and this is 1018 cold work that means the process came condition is this material was worked at lower temperatures with big rollers and massively crushed so it's kind of like

37:14what you guys did cold working this is cold worked okay now I've taken and cut some samples for you guys and I have different ones here for you and basically it has two samples in one I've got one that's squarish so the one that looks more like a square is the annealed sample of 10 18. so that's going to be

37:33recrystallized correct the next one is kind of like a long rectangle and I want you to think about that long rectangle that I squished it down in that direction that's the direction it came out of the sample that it was cold work so again when you put it on the microscope you're not going to be able to put it straight where the column is

37:49coming this way you're going to have to rotate it where it's squashed this way and then what you're going to be able to do is just move using the side of the machine from one view to the next on there and compare the differences of recrystallized and cold work 1018 Steel make your observations we'll be putting that in your report

38:07so anyway I hope that helps you guys out with this lab a lot of fun we'll see in lab