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Module 1: Additive Manufacturing Overview

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Additive Manufacturing Applications

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Additive Manufacturing Application for Prototype, Tooling and Part Repair(Refer Slide Time: 00:15)
Good afternoon, my name is Vaman Kulkarni. I was ex-director of mechanical systems inHoneywell technology solutions. I just took an early retirement a couple of months back fromHoneywell. As part of the mechanical systems group at Honeywell, I was responsible foradditive manufacturing initiative, we set up a state of a art lab in Bangalore for metal printing.That has been my involvement in additive manufacturing for the last 6 years.
And we make the significant progress in developing the additive manufacturing technology.Before joining Honeywell, I was with DRDO gas turbine research establishment for 21 yearsinvolved in developing the gas turbine engine Cauvery engine for LC applications, that is mybrief background. Today's topic is additive manufacturing applications for prototype, tooling andpart repair.(Refer Slide Time: 01:28)
This has been one of the key areas where additive manufacturing has been widely used. In fact,that is what I like this staircase model from Renishaw which shows that at the bottom we havethe rapid prototyping tooling. That is where the application of additive manufacturing startedway back and with the lot of improvements which are happened in the metal printing.
It has taken a much different shape in taking advantage of the functional prototypes, the toolingand then the part repair applications. It is across the industry. It could be in the aerospaceautomobile or in the medical. So, it is across the field it has been a significant part of it. Additiveis also today used for a lot of production applications whether it could be a direct partreplacement or consolidating the parts or in a new product development as part of the as a designfor additive manufacturing benefits what additive are brings in. As part of the prototypestypically if their main rapid prototype has been very widely used for last 20-25 years. But rapidprototype need not be always with additive manufacturing. So, the rapid prototype means thathow quickly we can make the prototype and then quickly do some of the functional checks andsay which helps to finalize the design very quickly or do some design iterations.
That is when the prototype has been very widely used. So, additive plays a very big role as partof this new product development to do the quick design validations and it reduces the overallproduct cycle time. Prototypes are also used for a lot of visualization, checks, and especially
from the assembly and maintenance point of view, the user experience, how it is easy toassemble and maintain it.
So, that is the other thing which you can verify. It is also used to provide the early customerdemo of parts, so that he can use it for the next assemblies as well as a lot of functional tests.Today in fact it is also used for a lot of field trials. As far as the tooling is concerned especiallywith metal additive manufacturing, it is been playing a big role in developing manufacturingtools especially the casting and forging moulds and dyes.
It helps to come out with a more optimum design of dyes and moulds which will have bettercooling. It will help in having a better quality of the part as well as in increasing the life of thetool itself. It also reduces the downtime because the tools can be quickly made with additivemanufacturing. Lot of tools which are required for assembly and assembly requirements couldalso be done through the additive.
In quite a few instances, when the part is being tested lot of test tools or test fixtures needs to bedeveloped in a very short period of time. So, I think definitely have the advantage of supportingthat. The part repair has been in existence for last 20 years, but most of that because of the directenergy deposition using the laser technique.
But with DMLS coming up in a big way in last 5 to 6 years. It is been very widely used acrossthe industry to repair the worn-out parts as well as last minute any design changes could beincorporated very quickly onto the part which is already manufacture. So, those are the benefitswhich additive brings as part of part repair. So, we will be looked into the in all these 3 areasbased this additive technology is, and then how it is being applied and there are some goodexamples which we have deployed additive manufacturing in all these three areas.(Refer Slide Time: 06:26)
So, before we get into that what benefits additive manufacturing brings, when I talk aboutadditive manufacturing mainly, we are focus is on metal printing, that is been our main focus.So, definitely the advent of metal printing, we are able to design a very complex parts withadditive which helps in improving the performance, life and it could be lightweight. So, those arethe things which additive manufacturing enables whether it is part of prototype or it is part of thetooling or the part repair.
It also empowers the designers to consolidate the parts into a single design. It removes the lot ofconstraints which used to be there while designing a part keeping the manufacturing constraint.So, most of that is eliminated because of the process of additive manufacturing itself which isbuilding the part layer by layer. Additive definitely reduces the cycle time because there is noneed for the tooling.
Assembly time is also reduced because we can consolidate all the parts. It is ideal solution forvery complex parts and which where there is a low volume which is the case with prototypes.There is no lead time involved to get the materials because the powder which is used is alreadyeither in stock or we can get the powder very quickly. Because of the process itself there is nowastage of material as far as additive manufacturing is concerned.
It can come out with the very light designs; the lighter designs could be because of using thethinner materials or it could be because of the lattice structures. So, we can come out with a verylight part from additive manufacturing. Typically, when you want to get the prototypemanufactured, we always go to our suppliers who can do this at a low cost and with additivemanufacturing we can have this done very close to the either the internal customer or the externalcustomer where it will get into the next assembly or testing.
Because there is very less content, labour content involved as part of this and it also reduces thetransportation cost and time. If the additive manufacturing process itself is very agile, very latedesign changes could be incorporated easily. The part can be produced, so we can be moreresponsive to the customer changes and customer request and we can incorporate that into thedesigns. So, all these benefits will definitely help when you as you get in to the prototypes or fortooling or for the part repair.(Refer Slide Time: 10:03)
There are quite still a few challenges with additive manufacturing technology. These challengescould be in terms of achieving the final accuracy, dimensional accuracies, geometricaltolerances, the surface roughness. All this is decided by the powder size, the quality of thepowder, the layer thickness. So, it still needs some sort of a post processing to address the finalfinish. But still it could be done much faster than the conventional but there are with theselimitations still exist.
Similarly, the quality of the part which is built that still needs to be consistent and reliable withthe quality of part is affected because of the residual stresses or because of the distortions whichcould happen while printing. So, these things cannot be accurately printed, so it needs to bevalidated especially when you are building a larger overhang part. So, there could be somewarping issues which needs to be addressed and needs to be adopted and supports need to beoptimized.
So, there is still a manual intervention and some sort of trial which needs to be carried out. Thereis still limitation on the size of the part what can be printed. 400 millimeters by 400 millimeter isnow very well established. But there are machines which are now available which can build upto 1-meter length, breadth, and height but it is still being validated. So, as time progresses, I thinkthe size will grow a part of additive manufacturing, not all materials can be sintered with today'stechnology.
So, we still have some limitations, we may not be able to print magnetic materials or the hardtool steel. So, there is still a constraint as far as the material is concerned. So, as I mentionedearlier there are, we still need to do a lot of post processing. The minimum post processing orany part which is built on a is to go for the stress relieving and then some sort of a surface finishprocess either it could be shot peening or chemical etching to improve the surface finish.
On need basis depending on the criticality of the part you may have to do the heaping; heaping isthe hot isostatic pressing process which will remove the porosities and then it increases thedensity of the part and enhance the better material properties. Depending on the dimensionalaccuracies, we may have to do some post machining. So, those are the aim challenges, I have justwanted to keep it up front before we get on to the details of applications of prototype tooling andthen the part repair.(Refer Slide Time: 13:18)
This typical rapid prototyping process is what we shown here. So, we get a concept design thenthe concept design is converted into a build. The build could be out of additive manufacturing orit could be out of conventional machining or it could be out of casting. That is where we need toidentify the right process, so that we can reduce the cycle time and then that is what is review.When you say review it is the design is validated for the performance, for the assembly. So, itwill undergo some of those trials as part of the review.
And then you go back and then change the refine the design and then you do some iterations,finally have a build which can get into the production. So, this is where the in nutshell how therapid prototyping process looks like. A prototype could be for the proof of concept or it could bea demo model for the customers or for the both the internal and external customers and then italso gives a visual feel of the things and then you can also validate all the functionalities forwhich the product has been developed.
It could be also for the aesthetic purpose, how it looks like. Because that plays a big role whenyou have to get the product into the market or it could be the initial test builds which you releaseit like an alpha or beta versions, this could be for the hardware or software the word prototype isapplicable across. So, in our scenario we specifically are looking at the mechanical parts as ourfocus.(Refer Slide Time: 15:17)
What benefits the AM brings it when you look at for the prototypes? One of the key things whatAM enables is the quicker performance evaluation. So, we can have the design converted into aproduct which we can do all the functional tests whether it could be at a higher pressure ortemperature. Even if you are not using the original material, it can still be tested for all thosefunctionalities. It may not withstand the life for which the product needs to be designed but it canstill be evaluated for all it is performance.
So, that helps to quickly validate the design and then do the design improvements and thenquickly build the parts and test it. I have few examples where you can see that how it is reallyreduce to the cycle time by more than 70%. AM is definitely a cost-effective solution forbuilding the prototypes because it is a completely automated process, there is less laborinvolvement in building the part and of course there are no tools are required.
It is we can get a complex part with an extreme precise dimension because it is directlyconverted from the CAD models. Material wastage as we talked earlier it is very nil and any riskinvolved in the manufacturing. So, those risks can be very easily addressed and it can be quicklysolved using additive manufacturing. Because as I told the last-minute changes can still beincluded into the design before we start actual printing.
We can take these prototypes quickly to the customers or the board members and then get quickapprovals for the full development of the product. It also helps to any inputs which comes fromthe customers very late in the design phase and then we can incorporate that into the prototypesand then we can validate it. So, it really has that flexibility to produce the parts.(Refer Slide Time: 17:52)
The applications of prototypes talked about the new product development is plays a big role. Wecan do the very quick design validations. Design for assembly, we can validate this assemblychecks, we can take it to the customer demos and any maintainability related things from the userexperience point of view. All that can be validated very easily with these additive prototypes.Sometimes we need the prototypes to take it to the customers which helps our marketing andthen the sales channel to win the businesses.
So, we can quickly modify the existing product or the new opportunity and then we can quicklyengage with the customers. So, that helps in the whole business win process. It also gives a lot ofinputs when we start preparing the bits both for the technical as well as the commercial piece ofit. We can use these prototypes to have both the technical feasibility as well as the commercialvalidations.
Even before we engage the final engagement, we can give those demo pieces to the customer.So, that he can evaluate it and then get the confidence of the customers. In many cases whatever
field failures which we see in the field we struggle to find out the root cause and then come outwith the corrective actions. So, if you are able to reproduce the failure what you see in the field,then we can come up with a design fixer. So, the additive manufacturing prototypes helps toquickly make those prototypes and reproduce those failures.
And then incorporate those design changes, test it and then validate it. We can also use theprototypes for the pre production field trials which helps to make sure that it functions properlyin the bigger assembly scenarios. In some cases, there is a need to upgrade the existing partthrough additive manufacturing because of various concerns and issues. It could be because ofthe supply chain issues where we have some tough time with the suppliers or the tooling which isinvolved is gone bad and then there is not tooling drawings available.
Especially this is true in an aerospace scenario where there is a long life for the product.Typically, most of the aircrafts have a life cycle of more than 30 years. In such a situation for theparts which are 20 to 30 years old, we may lose the inventory of the tools to manufacture thepart. So, for we can there is may be a requirement to replace those parts with additivemanufacturing. In some situation because of the longer life cycle we may want to reduce the costof the product.
Because that design which is old design is gone through a costly manufacturing process ofmaybe casting or forging. So, it may be in the present technology is easy to either do it throughthe additive or do it for the hog out. So, we can do those design validations with theseprototypes. In some cases, the part could become obsolete either because of the material itself orbecause of the older manufacturing process.(Refer Slide Time: 21:59)
So, those are the areas where additive brings lot of benefits and advantages. So, in the next fewslides, we will see few examples of prototypes and how it is benefiting the industry. You can seehere high-pressure turbine blade, typically most of these high-pressure turbine blades have acomplex airfoil. As well as they need to be internally cooled to withstand the very hightemperatures.
So, when we use the design process for these things, doing all the thermal analysis, the flowanalysis, the CFD analysis and come out with the design and to manufacture these blades it couldtake anywhere from 6 to 9 months to manufacture these plates. And then we had to test it andthat could take another 4 to 6 months for the testing then we further if you have to modify anydesign changes, it is a cycle of one to one and half years what we were talking about.
Typically to finalize this type of a design, it takes about 3 to 4 years to finalize a design. But withadditive manufacturing we can have this part available in less than 8 weeks. This one wasspecifically with Honeywell went through 4 design iterations and in those 4 iterations we couldvalidate the design and then finally, the final production is not done through additive but it is theprototypes are done through additive.
And then all the validations are done and then it is released for production. So, it has reduced thiscycle time from 3 years to about 6 months the entire whole design iterations what you are talking
about. The cost savings is also more than 500,000 dollars as part of this product development.So, same thing with should be high pressure turbine nozzles. You can see the complexity of thepart which is involved, so additive is used for prototyping. It can finally be processed for evenfor the production version but that also depends on a lot of validations and the certificationswhich is involved.(Refer Slide Time: 24:40)
The next one is the TOBI nozzles. TOBI nozzles are the tangential injection of the cooling flowon the turbine blades to at the right pressure and temperatures, so that is a criticality of theseTOBI nozzle designs. We could quickly get these things manufactured through the additive andwe can take it to the testing. So, the one which is printed through additive may not have the lifewhat we are looking at. But we can take it to the next assembly like engine testing.
So, we can do those validations even at the engine level. That way the overall cycle time for theoverall engine development we could reduce it. If we had gone through the conventionalapproach to make these parts available, it could have taken around 9 months. So, all in all thereare quite a few other models what you can see here as part of the prototyping. The typical cycletime in an industry what we can reduce is closed about 70% and can have a cost reduction ofabout 65% and then we can do more design iterations and have a different thing completelyaddressed through additive manufacturing.(Refer Slide Time: 26:11)
So, in many cases we do not make the prototypes for the actual material, we can make it out ofpolymers or plastics. So, there are some examples which I am showing it here. On the right-handside, you can see that this is for the solenoid. The coil winding is the critical thing for thesolenoid. We can do the winding trails on the bobbin of a polymer bobbin and then do all yourwinding trails and then finalize it and then reproduce that on the final part also.
Similarly, you can see on the limits which where the PCB assemblies stacked and need to checkthose quick assembly trials. Also, we could quickly make a plastic part and then assemble it andthen check it and finalize the design. So, that way if it is although it is a non-functional part but ithelps in finalizing the design from the assembly and then design validations.(Refer Slide Time: 27:33)
Coming to the tooling, so tooling is another big area where additive can play a big role. Thereason why the tooling application is very wide for additive manufacturing is. The tooling is notgetting into the final product, so we do not have to we can keep the tooling design in mind comeconsidering the overall product application and then there is no need for any additionalqualification or certification of the tooling itself.
Similar to the prototypes but most of the cases the tooling what we talk about is the tools whichare required either for the moulds or the dyes in a casting or a forging process or the toolingcould be for the assembly fixtures or even when you are doing the conventional CNC milling ordrilling you need to have those fixtures to hold the part, so may require those tooling. Some ofthose tooling needs will come requirement will come very late and it could take time if we bothhave the conventional approach.
In many cases the tooling will decide the quality of the end product and to address that qualityrelated issues, the tool needs to be efficient. So, that quality of the final part is not affected. So, ina molding industry typically we have two types of tooling, one is the direct rapid tooling. In thedirect rapid tooling, the entire mould assembly is produced through the process AM process.
The rapid tooling could be completely done through a conventional process or it could be donecompletely through an additive manufacturing process like DMLS or SLS or it could be hybrid.
Typically, the hybrid process takes advantage of both conventional as well as the additivemanufacturing. So, that we get the optimized tool done, both in terms of cycle time as well as thecost. In the indirect rapid tooling, we are not making the complete assembly. We have more thanone intermediate steps in manufacturing the core and then the cavity, so that is the indirect rapidtooling.
So, there are two examples are shown in the bottom, the first one is a cooled insert which is donethrough the hybrid process. It also incorporates the conformal cooling, so that we reduce thecooling time for the mould itself. So, the complex part which is on the top what you can see herewhich also has the conformal cooling. So, that is one which is done through the additivemanufacturing.
The bottom one which is much easy to machine that is what is done through the conventionalprocess. Similarly, you can see here an example of when intricate mold which could be donethrough the conformal cooling in a much better way which reduces the cooling time as well asuniform cooling, so that we get a better quality of the part.(Refer Slide Time: 32:14)
So, few more examples of the tooling here. This is a flow mixer; this is a test rig part for testingsome of the flow meters or any other flow devices. So, this one we can come out with a realinnovative design using the additive manufacturing by which we can reduce the cost. We can
also reduce some of the back pressures which otherwise will be there with the conventionaldesigns.
Then there is a coating box, so this is the coatings which you do on the parts, so that fixturewhich is required for these coating. So, the conventional design would have taken about 8 weekswhereas we could do an additive in 2 weeks, so reducing the cycle time is a key thing. It is betterdesign from the assembly point of view.(Refer Slide Time: 33:28)
This is another good example of the rake, the measurement. It measures the pressure across theairfoil. Typically, this takes a lot of time to make it through the conventional process. It alsoinvolves a lot of welding, brazing and then the EDM machining if you follow the conventionalprocess. Additive is the right way we can make this part and eliminate the welding, brazingwhich helps in reducing the cost as well as the cycle time.
So, and few more examples are shown here for the tooling applications. Typically, we can reducethe cycle time more than four weeks. We can also reduce the cost and then we get a betterperformance from the tooling.(Refer Slide Time: 34:36)
So, since we are using additive for these toolings we can take benefit of this additive. This is atypical application for the conformal cooling applications. So, when we do the mould designs,we always keep in mind how that mould can be produced. With the conventional of machiningwe can always have the straight, vertical or the horizontal or the holes we cannot have the curvedholes.
Because of that typically the cooling time is cannot be optimized. So, the pie chart here you cansee that out of all the cycle time in the injection molding, Cooling is the one which is takesalmost 50% of the time, what is shown here is in seconds. So, cooling takes almost like 18seconds out of the overall 35 seconds of time what it is takes. All other process which is involvedinjection molding takes the remaining 50%.
So, this can be optimized by coming out with the additive manufacturing design. We can comeout in the complex informal cooling channels which otherwise is impossible to produce using theconventional approach, which helps in the quality of the product by having a uniformtemperature. It reduces the cooling time, so it increases the production rate and then the tool lifeis also increasing.
So, we can optimize the design and then we can verify validated through a mould flow softwareand then finalize the mould design.
(Refer Slide Time: 36:28)
This is a practical example of deploying the hybrid conformal cooling. This is for one of the firesafety devices what we are talking about. The mould design was optimized by using the mouldflow software and we could get a reduced cooling time of more than 50% as part of this. Thisdesign can see here that the conformal cooling which channels which are incorporated. So, thatwe can quickly cool the mould and then you also get the uniform temperature.
The process which is followed is we have the engineering team which is the product design teamand then we have the AM team involved to design these tools and then the production agencywhich will implement this and then validated it. This whole thing was validated where in theproduction rate we could increase by almost 50%. The 5000 parts which were able tomanufactured in a day.
We could increase that to 10,000 parts in a day. So, that is the validation of the things and thenwe could demonstrate a cost savings of about 300K per annum as part of this part. So, this is agood example of using conformal cooling for the mould design.(Refer Slide Time: 38:21)
The third topic which I want to touch upon is the using additive manufacturing for the repair andrestoration. This is not a new thing which is already in use in many of the applications could beautomotive or for the marine components or for the aerospace components. We refurbish the partas a new condition and then it can have an additional life incorporated. Examples are for anautomotive it could be an engine block or it could be some defects which would come into theengine blocks and then that needs to be addressed.
Or it could be marine components like the crankpin journal where it could have a lot of cuts,ridges and then the grooves and then it needs to be grinded and finished. Or aerospace part like itcould be a landing gear or a flight control actuator or a gas turbine engine parts like a turbineblades or a compressor plates which could worn out near the leading edge. So, those are the areaswhere we can deploy the repair.
The additive manufacturing technology for the repair, most of this thing has been around thedirect energy deposition which is more like the laser cladding or the laser metal deposition whichhas been in use for the last 15 to 20 years. So, that is what has been largely used but in the recentpast with lot of improvements were happening in the DMLS or the EBM or the SLStechnologies.
The powder bed fusion is been extensively used for repairing the parts. Especially the complexparts, it is much easier and can be done in a much more precise and an accurate way. For themost of the plastic parts FDM is the one which is used polymers or plastics. So, that is wherethose are technologies which are being used.(Refer Slide Time: 40:39)