SPECIALFEATURE

Metal Powder Report � Volume 70, Number 3 �May/June 2015 metal-powder.net

Mapping out the additive manufacturinglandscape

Stewart Bland and Brett Conner

There’s no denying that additive manufacturing is receiving an enormous and increasing amount of

interest from industry and academia alike. But how can companies navigate their way around this

emerging landscape? Metal Powder Report spoke to Dr Brett Conner, lead author of new study in the

journal Additive Manufacturing that introduces a system to map out potential products and help

businesses make informed decisions.

E-mail address: bpconner@ysu.edu.

0026-0657/� 2014 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.mprp.2014.12.052

Dr Brett Conner is a Professor of Industrial and Systems

Engineering at Youngstown State University (YSU), Youngstown,

Ohio, and lead author of the paper Making sense of 3-D printing:

Creating a map of additive manufacturing products and services [1].

Located in the middle of America’s Rust Belt, Youngstown is now

the home of America Makes, the national additive and manufactur-

ing innovation institute. As a result, Youngstown State University

has established a Center of Innovation, of which Dr Conner’s

research group is a part. In turn, the Center benefits from YSUs,

strong materials characterization capabilities, to develop new

materials, and conduct materials process development for additive

manufacturing.

Dr Conner, can you tell us about your work at theCentre and YSU?We look into applications of additive manufacturing that

is enabled by digital design and manufacturing. We are inter-

ested in the digital thread behind additive manufacturing that

allows us to make new products that we have not been able to

make before. We also have a strong emphasis area in precision

post-processing of metal parts. Just because you are done

printing the part using additive manufacturing, it does not

mean that is the last step, so we look at precision post-proces-

sing, including subtractive methods and heat treatments and

metrology.

We also work on innovative business strategies and

approaches, and entrepreneurship enabled by additive

manufacturing, or 3D printing. So we have got a broad role at

the Center: primarily materials-related, but now we also have a

business piece as well.

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Three axis model of manufactured products. Reproduced from reference [1].

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You’ve recently reported on creating a map of additive

manufacturing products and services in the journal, Ad-

ditive Manufacturing [1]. Now, why do we need to be able

to map out the 3D printing landscape?

People use maps to work out where they are and determine

where they want to go, and so basically the map provides clarity. If

we look at additive manufacturing (also called 3D printing), we see

so much hype around it, and there are multiple 3D printing

technologies. The ASTM (American Society for Testing and

Materials) has seven different categories of added manufacturing

technologies, and within each of those categories are various

technologies from different vendors. We can also look at the

product opportunities as well. In 3D printing, there are so many

different opportunities: in aerospace, in defense, in medicine, in

industrial products, consumer products, automotive. It can be

quite confusing for any sort of entity trying to enter into this

field, and so having a map of additive manufacturing products

and services is going to be useful to business executives, to entre-

preneurs and investors, engineers and product development

teams, researchers, and even students.

How do you go about starting to map outmanufactured products?Any type of a map requires a reference system, and here we are

going to look at key attributes of manufacturing, and there are

many attributes of manufactured products. But what we decided to

do was focus on three main attributes. The first one is product

complexity, and that could be a geometric complexity. You could

look at a manufactured product, and recognize that that is a

complex part geometrically. You could also increase complexity

by incorporating multiple materials into that part. Complexity in

general with conventional manufacturing tends to be expensive.

The more complex something is, the more expensive it is to

manufacture. Just taking geometric complexity alone, and looking

at subtractive manufacturing, there will be more tool paths and

potentially different types of tools, to be able to make a complex

part. And that just means more costs, more time that the part is

going to be in the milling machine or the product center – and

that’s going to translate into more cost.

Now, the second attribute that we looked at is customization,

and here we define customization as the uniqueness of a product.

So many products that we see, just considering consumer products

alone, you find many products that are pretty much the same. But

if we looked at customized products, we find low-hanging fruit

there in terms of medical applications, for example, prosthetics or

implants, those can be highly unique and tailored to just that

individual. Again, with conventional manufacturing, customiza-

tion generally involves increased cost. We’re either talking about

large labor costs – touch time on that product, even hand-crafting

– or a significant amount of time trying to set up equipment. So we

have this mindset in terms of a customized product being a volume

of one, but that is not the case, and so we’ll get into that a little bit

later: that production volume and customization are not neces-

sarily the same. But that leads us to the third attribute, which is

production volume, which is the quantity of a given product being

produced in a timeframe. If you take these three attributes, you can

basically come up with a model that is three-dimensional – there

are three axes: one for complexity, one for customization, and one

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for production volume, and within those axes you can contain a

cube with low and high regions of each attribute, and so that

becomes our reference system that we can use to describe manu-

factured products, and specifically additively manufactured pro-

ducts.

Is it possible to break this 3D manufacturing spacedown any further?Sure; I mentioned this model has eight different regions in it, so

let’s look at a few of these regions. Let’s first think about a region

where we have low customization, low complexity, and high

volume, and what that describes is traditional mass manufactur-

ing, where we drive out complexity, and we basically eliminate

customization, in order to reduce the cost for manufactured parts,

and it becomes a cost-driven exercise. Sometimes we try to entice

consumers by giving them a selection of pre-determined options

chosen by the manufacturer, but it is still low customization. So

how we conduct our product design is basically driven by cost,

and so we talk about design for manufacturing and assembly.

Now, if we look at low customization, low complexity, but low

volume, that now brings us into a different region of manufactur-

ing, again one that’s occupied by traditional manufacturing.

However, this is the region where additive manufacturing was

born. A prototype is essentially a low-volume product. Here a

prototype will represent a product that’s going to be manufactured

using conventional mass manufacturing processes, so the custo-

misation and the complexity are going to be low – but it’s the

region where additive manufacturing was born as rapid prototyp-

ing. For rapid manufacturing, instead of having to wait for tooling

and fixturing to arrive, and instead of investing in tooling and

fixturing, we can now manufacture using additive manufacturing.

This is a region where additive manufacturing can potentially play

a role, but has to compete against conventional manufacturing. It

has to be cost-effective, and it has to be perhaps faster, and may

Two families of parts where increasing complexity leads to reduced weight.Reproduced from Ref. [1].

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mean dealing with products that are made of extensive materials –

nickel-based super alloys, titanium and so forth: where conven-

tional manufacturing is quite expensive. In this region additive

manufacturing may have an opportunity here to reduce costs and

reduce the time to manufacture. People are already comfortable

with those regions of the model, because that’s traditional

manufacturing, but let’s look at trying to increase complexity.

Looking at an example where we have low volume manufactur-

ing and no customization and high complexity. Why would

anybody want to have a more complex product? It’s usually

because we are trying to solve a problem: we could be trying to

make something lighter in weight; it could be that we want to have

a more efficient heat exchanger; it could be that we have a product

that requires a great deal of aesthetics, something visual, perhaps

related to artwork; or it could be something where the challenge is,

right now, to make that complex part we have to make a bunch of

simple parts, and then join them together. So if I can make it more

complex, I could consolidate my parts from ten or twenty to one,

and we’ve seen examples of these recently: for example GE Avia-

tion, and the LEAP engine fuel nozzle, where we took a part that

was originally twenty assembled parts, and consolidated them into

one 3D-printed part, with a complex internal structure to enable

more efficient fuel flow. We also see this, again with GE, for engine

brackets, and Airbus, looking at brackets for aerospace structures,

where they’ve taken conventional bracket designs and made a

more complex geometry, only putting material where it’s needed

in the structure for strength and for stiffness, and coming up with

something lightweight.

Now, let’s consider one other aspect here: customization. Cus-

tomization is something that’s unique, and I am going to talk

about high-volume customization, or mass customization. This is

something that would be practically unthinkable using conven-

tional manufacturing, because you wouldn’t really want to fabri-

cate tool for each and every customized part, but it is possible to

use 3D printing to do this, and an example of this is Invisalign

braces, or invisible aligners to straighten teeth. Each one of those is

highly customized, based on impressions and x-rays of the patient.

The company that makes those components, creates 20 million a

year. Now, the aligners themselves aren’t 3D-printed, they’re

thermoformed plastic, but the tooling to make each and every

one of those is 3D-printed using stereolithography. 20 million

customized parts a year, mass customization – that’s very revolu-

tionary. So those are just four out of the eight regions in the model,

but it gives you a feel for how different additive manufacturing

is from conventional manufacturing.

Is it possible to go beyond the qualitative description,and start quantitatively placing real products in thisspace?Yes it is, and that’s one of the key discussion points in our paper

[1], and a key portion of this research. We were able to look at

complexity, geometric complexity. We focused on that topic. We

used models that we found in the literature for casting. Casting

components are relatively complex, for conventional manufactur-

ing methods. We found some models that were based on casting,

and looked at things like the surface area of the part, the volume of

the part, the bounding box of the part, and if it had other features

that were casting-specific, we adapted them to look at aspects such

as the number of holes in the part. For example, if you make a

lattice structure, there are many open spaces inside the structure,

but for additive manufacturing, it’s perfectly fine – we can go and

print it that way. So we were able to modify this, and come up with

a quantitative and continuous complexity factor, such that we

could take products and look at them at a scale, and compare them

to each other using a complexity factor.

Now, onto the customization side, we didn’t have something

that was continuous, but we were able to develop discreet levels of

customization, so we could look at a product and assign it a level of

customization. We came up with five different levels, ranging from

something that is not customized, all the way to something that’s

truly unique, but the key dividing point between what would be

considered low customization and high customization is a situa-

tion where we have a product that includes one feature that is

customized by the customer, and it’s not pre-determined by the

manufacture. Now, I mentioned that in conventional manufactur-

ing, manufacturers will try to give their customers some level of

selection, but those are all pre-defined by the manufacturer, and

they can arrange tooling and fixturing. But if we’re looking at

features within that part itself, such as geometric features, that are

determined by the customer – you can’t really prepare for that. But

in 3D printing, you don’t have to prepare for that. You don’t have

to have the tooling, you don’t have to have the fixturing in place –

you can just print it, so we came up with discreet levels. So the

combination allows us to be able to place a product within specific

regions of the model, and have a more focused discussion.

Ultimately, what will mapping out parts and productsallow us to achieve?I can think of four different opportunities that come out of this

model. There are more, but four that I want to emphasize here.

First of all is that we can allow businesses to determine which

portion of their product portfolio is best suited to additive

manufacturing. They can look at their existing product portfolio,

be able to quantify the level of complexity, be able to determine

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A rotor and stator for oil & gas applications. The components were printed

using the binder jetting process. The material is stainless steel

420 infiltrated with bronze. Courtesy, Brett Conner.

An ExOne M-Flex binder jetting printer. Courtesy, Brett Conner.

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the level of customization, and determine whether it makes sense

to use additive manufacturing. We can also help businesses deter-

mine how to best optimize products for 3D printing: their current

product portfolio may not be suitable for 3D printing, but if they

were to, say, change the geometry of a product, much like we saw

with the GE engine bracket, they can change the geometry of the

product to make it lighter weight, or to have some sort of func-

tionality that is enhanced by additive manufacturing. The model

basically allows the company to think about how to optimize

those products.

It also allows us to rethink business models, so when we’re

trying to emphasize complexity and customization, we have to

rethink how we engage our customers. On the complexity side, we

have to rethink the engagement between design engineers and

manufacturing engineers, even if they are within the same com-

pany. Even if the company is vertical integrated, we still have to

rethink the way that we bring those together, and rethink the

design cycle into something that’s more iterative and more exper-

imental, versus trying to keep everything virtual, and then sending

it to a production center that’s far away. We can see greater unity

between design and our manufacturing.

Also, if we look at consumer products, we can think about how

we’re going to engage customers from a customization standpoint.

Now obviously, if you are making invisible braces, there is an

existing customer engagement point through dentists’ offices,

but if you’re trying to make something like a 3D-printed shoe, or

you’re allowing the customer to change the color of the shoe and

the shape and so forth, you need to think about how you are going

to engage those customers, and the services that are required.

There are other things too, like rethinking the supply chain –

where are you going to put your manufacturing equipment?

Instead of focusing on cost, where you were going to place the

manufacturing location where you can have the lowest cost capital

and infrastructure and labor – now you’re thinking about where

the value proposition may be best, and move your manufacturing

infrastructure closer to where the customer is.

Lastly, I think that this model can help to guide research too,

even materials research, because now we think about how research

and additive manufacturing is going to affect and enable com-

plexity, and how it is going to affect and enable customization,

and then production volume. A lot of additive manufacturing

processes are batch-based, and for many products, that’s good. But

greater speeds, process times and cycle times can open up other

product forms, where we can get into increasing mass customiza-

tion with items that are larger than invisible braces, so there is a

need to speed up the process.

What’s the next step in the project?One thing that we are doing now, with funding from America

Makes, and working with the Youngstown Business Incubator, the

American Foundry Society, the University of Northern Iowa, and

several small/medium business partners, and a 3D printer compa-

ny - we are looking at implementing this within the US metal

casting industry. Many businesses in that industry are small busi-

nesses that are involved in sand casting, and we can use 3D

printing and sand to be able to make the molds and the cores.

The challenge is for small and medium business executives, is the

cost of trying to acquire the capital, but also, where does this make

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sense in our product portfolio? What are the new business oppor-

tunities? If they’re going to jump into this field without making a

major investment, how can we enable that? So, we are trying to

use this toolset in casting, looking at comparing the complexity

factor, that continuous complexity factor, with product cost, and

trying to look for that break-even point on this complexity factor,

trying to look at the break-even point between conventional

pattern-making for sand casting, versus 3D printing. So that is

going on right now, and we hope to have more results within the

next year, and implementation of this and this toolset in the

metal casting industry.

The other thing we are trying to do is perform more research on

describing and quantifying customization. So we have a discreet

scale for customization, but can we have a customization factor

that’s continuous, a continuous function, just like we see with

complexity? Also, what has to go behind customization on the

services side? What is needed to be able to enable consumer

customization, which could be quite disruptive to manufacturing?

So those are a couple of the next steps in this project, and we’re

hoping to see some fruit in both of those areas this year.

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Finally, what are the other hot topics in additivemanufacturing right now?I think one area is developing new materials designed specifically

for additive processes. If you look at additive manufacturing

today, take metals, for example. A lot of the materials that are

being used are materials that are well-known on the conventional

manufacturing side. For example in titanium, Ti 6-4 is a common

material for additive manufacturing, but it was never really

designed for a laser-based, or an electron-beam-based, energy

process. Could we develop an alloy of titanium that is well-suited

for the rapid solidification that we see in additive manufacturing?

And I think that that example can be extended to other alloy

families as well, and arguably on the polymer side. Now, on

polymers, a lot of work concerns looking at new additives and

fillers that could give the desired properties. That’s really an area

focused on the polymer side, but for metals I think that there’s a

great opportunity for alloy development and various metal sys-

tems, that will really take advantage of these processes. When I

worked in the aluminium industry, we had alloys that were

developed for quench-insensitivity for thick plate products, or

developed to get a strength boost during a tempering process.

So those were alloys specifically tailored for manufacturing pro-

cesses, and we have not really seen that yet in additive manufactur-

ing, and I think that that’s a ripe field for research.

The other area that I’m very much interested in, and our

research group is pursuing, is using additive manufacturing to

fabricate multi-material structures, for example, functional-graded

materials, or even multi-functional structures. There are technol-

ogies that exist now, for metals and ceramics, and also polymers

as well, where you can select where, in a given structure, you want

a certain material. So you could think about properties within a

structure, and maybe emphasize stiffness in one area and flexibili-

ty in another area. Historically we have done that through

manufacturing processes like roll bonding for alclad alloys, or if

we look in the polymer side, over-molding, but now we have the

ability to, during the manufacturing process itself, to place mate-

rials in a location that would be absolutely impossible to do

using conventional means. And this requires a great change in

thinking from the design standpoint, but there are also tremen-

dous opportunities on the materials side as well, especially for

functionally-graded materials. So those two areas: new materials

development and multi-materials, I think these are the hot topics

in the materials science of additive manufacturing.

Reference

1 B.P. Conner, et al., Making sense of 3-D printing: creating a map of additive

manufacturing products and services, Addit. Manuf. (2014), http://dx.doi.org/10.

1016/j.addma.2014.08.005.

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