Increasing in Additive Manufacturing...• 4 x 500W lasers, each can address the whole build plate...

transcript

10/06/2019

Increasing

productivity without

compromising quality

in Additive

Manufacturing

Marc Saunders

10/06/2019

• Renishaw introduction

• A new AM world is emerging

• Advances in AM system performance

• Quad-laser optical system

• Real-time process monitoring

• Gas flow and multi-laser processing

• Powder management & re-use

• Software and support

Agenda

About Renishaw

10/06/2019

World leading metrology & engineering company

Metrology Research Healthcare Additive

• FTSE 250 public company, UK headquarters

• Independent

• Strategic focus on breakthrough innovation

Metal AM machine builder and user

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AM machine production

AM medical implants

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Agenda

A new AM world is emerging

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• 20 – 35% CAGR forecasted

• Equipment sales set to triple

over next 5 years

• Strong growth in services

also predicted

• Industrial AM applications

are the main growth driver

• Metal AM is showing the

fastest growth

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What’s driving industrial AM growth?

We can create parts that were not practical

or economical to make before

• Produce complex geometries to

improve part performance

• Consolidate multiple parts to

improve reliability and reduce

inventory

• Light weight – only build material

where it is needed

• Create fully customised components

• Parts can be manufactured directly

without tooling

• Enables rapid design iterations

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High-value manufacturing

• Heat exchangers & thermal management

• Fluid transfer

• Structural parts where weight is critical

• Difficult-to-process, expensive materials

• Where extensive quality assurance is acceptable

• Customised or low / medium volumes

Mature applications

• Aerospace and turbo-machinery

• Healthcare

• Tooling

Applications where additive is more mature

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How AM will grow – lower part costs

Volume

Unit cost

marketHigh unit costs have

confined AM to low

volume, specialist

applications

Conventional

manufacturing

Additive

manufacturing

Reducing AM part costs

will open up new market

opportunities

market

expands

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How AM will grow – lower part costs

Volume

Unit cost

Conventional

manufacturing

Additive

manufacturing

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Part cost-v-mass – subtractive manufacturing

Processing

costs dominate

Unit cost

Material costs

dominate

Minimum

Subtractive

manufacturing

• Low-weight products are

expensive

• Material is too expensive to

remove

• Exotic alloys used to

minimize weight

• If we minimize processing

costs, material costs rise

• Minimum cost achieved by

balancing material and

processing costs

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Typical market segmentation

Motorsport

Unit cost

Minimum

Subtractive

manufacturing

Aerospace

Automotive

Industrial

(static)Industrial

(mobile)

Minimum

• Products often used in multiple

market sectors

• Same basic function,

performance, reliability

• Different value assigned to

weight and space claim

• Motorsport, space,

aerospace will pay more for

lighter products

• Automotive and industrial

sectors are more driven by

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In AM, a lighter part is a cheaper part

Unit cost

Minimum

Subtractive

manufacturing

Additive

manufacturing

Minimum

• In AM, we have a virtuous circle:

Lower part

cost=Productive AM

• The position and gradient of the

AM part cost-v-mass curve

depends on several factors:

• Material cost

• AM productivity

• Post-processing

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Design for AM enables market disruption

Minimum

Subtractive

manufacturing

Unit cost

Minimum

An innovative AM product

design could serve the

whole market

• One product instead of many

• Simplified product

configuration & sales process

• Reduced inventories

• Streamlined servicing

DISRUPTION!

Productive AM

Single product suitable

for all market sectors

AM is a business strategy

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• AM’s real impact is on competitive positioning:

✓ Product performance and efficiency

✓ Lower product costs

✓ Value-added services (e.g. personalisation)

✓ Responsiveness to changing demands

✓ New product development lead times

✓ Alternative production and distribution logistics

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Agenda

Productive laser powder bed fusion

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Higher productivity = lower part cost

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Faster laser powder bed fusion

• 4 x 500W lasers, each can address the whole build plate

• Efficient use of all lasers for any geometry – typically reducing build times by a factor of 3 to 4

• c. 50% increase in machine cost for 200 – 300% increase in productivity

• Machine component of part costs typically halved

More lasers = more variables to control

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Multi-laser coordination challenges

• Laser-to-laser consistency – power & focus,

across the bed

• Laser cross-referencing – relative position

& stability

• Laser task assignment – load balancing

• Multi-laser interaction – relative position

w.r.t. gas flow

Innovative optical system

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AM galvanometer mounting

• Compact mounting block for

8 motorized guiding mirrors

• All 4 laser beams enter build

chamber close together

• Each laser can address the

whole build plate – full

overlap

• AM mounting block includes

complex internal cooling

channels for optimum thermal

stability

RenAM 500Q

quad laser

overlap

Quad laser galvo

mounting

Flexible use of multiple lasers

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Adaptable laser assignment

• Each laser can address the whole build plate

• Flexible assignment of lasers to each task

• Build with 1, 2, 3 or 4 lasers

• Select number of lasers to suit budget and

required build rate

assignment

More lasers = more throughput

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4 x 500W lasers

3 x 500W lasers

2 x 500W lasers

1 x 500W lasers

llatio

Dynamic focusing

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source

Dynamic

focussing

mirror

F-theta

✓ Programmable focus

✓ Adjust for thermal drift

✓ Fewer optical surfaces

x Fixed focus

x No adjustment

x More optical surfaces

Programmable focus

• Active focusing upstream of the

steering optics

• Programmable focus control –

can be different for each laser

• No F-theta lens – reduced

thermal lensing

• Enables compact galvo mounting

• Multiple lasers pass through

single window

source

mirror

Precise, stable laser cross-referencing

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Process plane

High precision z-axis

• Optical encoder with a

1nm resolution for high

accuracy positional

sensing

Kinematic recoater

• Kinematic recoater

ensures a precise and

repeatable working

Narrow beam

spacing reduces

laser alignment

sensitivity to process

plane variation

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Agenda

Multi-sensor

High-frequency data across a

range of wavelengths

• Infrared thermal sensor

• Near-IR plasma sensor

• Laser input energy

Synchronised with actual galvo

mirror positions to enable 3D

modelling and visualisation

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Real-time process monitoring

Analysis software

• Collect and view process data

live as the build progresses

• View and compare data from

previous builds

• Software tools to change

thresholds and reveal

anomalous data

• Guide post process quality

assurance techniques

• Keep records by capturing

traceable process data

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Process monitoring data visualisation & analysis

Understand - gain insight into process performance

Record - compare and store traceable process data

Improve - check quality during the build to optimise output

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Process monitoring benefits

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Agenda

Effective gas flow

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• Inert Argon gas flow carries process emissions

away from melting zone

• Consistent conditions in all locations

• Effective handling of ‘dirty’ materials such as

maraging steel – reduced cleaning

Laminar flow of 2

m/sec across bed

High speed flow at

outlet effectively

removes emissions

High volume / low velocity gas

flow from chamber ceiling

suppresses recirculation

Single laser window

makes space for

ceiling perforations

Tensile testingStress-strain curve

• The more ductile the material, the more easily it can withstand tensile stress

• Good ductility = good fatigue strength which is important for loading stress, shows lack of defects in the build

• Correct chemical composition and good ductility allows users the freedom to use heat treatment to tailor

mechanical properties as required.

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High and consistent material properties

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Nickel super-alloy IN718

60 µm layer

Ti6Al4V Grade 5

60 µm layer

• Consistent melting conditions

• Lack of defects results in high ductility and fatigue performance

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But what if we provoke poor melting conditions?

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Multi-laser interaction mechanisms

Melting of a downwind laser can be affected by…

1. De-focusing by airborne condensate – leads to reduced intensity

2. Occlusion by airborne spatter – prevents energy reaching the bed

3. Incorporation of spatter in the component – large particles shield powder from laser energy

All mechanisms can result in lack-of-fusion porosity

De-focusing by airborne condensate Obscuration by airborne spatter Spatter incorporation

Ductility & tensile strength variation with downwind distance

-200 -150 -100 -50 0

Downwind distance (mm)

Downwind sample ductility vs. upwind

IN625-60um_AB IN718-30um_HT

Ti64-30um_HT Maraging Steel-50um_AB

-200 -150 -100 -50 0

Downwind distance (mm)

Downwind sample UTS vs. upwind

IN625-30um_AB IN718-30um_HT

Ti64-30um_HT Maraging Steel-50um_AB

Impact of downwind

melting increases

with distance

Fracture surfaces

• Classic ‘cup and cone’

ductile fracture

• No ‘lack of fusion’ defects

visible even at high

magnification

• Premature fracture

• ‘Lack of fusion’ defects

leading to localized

brittle failure

UPWIND DOWNWIND

Melt pool analysis

• InfiniAM Spectral real-time melt pool monitoring

http://www.renishaw.com/en/infiniam-spectral--42310

• Downwind sample exhibits more variation in visible /

near-IR spectrum – evidence of hot spots due to

spatter passing through the laser beam

• Downwind sample exhibits lower average IR signal –

evidence of de-focusing and obscuration of the laser

Downwind Upwind

Photo-diode 1

Visible / near IR

Photo-diode 2

Infra-red

Multi-laser build strategies – multiple parts

1 2 3 4

Gas flow

Laser 1

Laser 2

Laser 3

Laser 4

Build in columns from left to right

1 1 1 1

2 2 2 2

3 3 3 3

4 4 4 4

Gas flow

Laser 1 Laser 2 Laser 3 Laser 4

Build in rows from back to front

Avoids downwind melting Downwind melting

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Agenda

Minimising material costs by maximising powder re-use

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• Rapid inert atmosphere generation using vacuum

& Argon purge

• Sealed machine enables 0 ppm oxygen during

• Integral powder handling keeps powder under

inert atmosphere at all times

Powder is never exposed to oxygen or moisture

throughout the cycle

Ti6Al4V re-use on RenAM 500Q

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• Series of builds, topping up

with new powder after each

• Oxygen and Nitrogen

remain with specification

limits

• Hydrogen drops from high

initial levels as powder

‘dries out’ with repeated

• Further data to be

presented at AMPM0

rstitial ele

tion (

Oxygen, Nitrogen and Hydrogen trends in Ti6Al4V

Oxygen Nitrogen Hydrogen

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• Software & support

Agenda

Software productivity tools

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Build preparation software

Orientate, support, slice

and material development tools

In-process monitoring

Identify potential defects

Compare serialized builds

Productivity Management

Machine utilization and status

Data acquisition and analysis

PLAN CONTROL MONITOR

AM process chain

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Design for AM AM build Gauging Machining Inspection

cesses

Support for process development - AM Solutions Centres

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• Try before you buy: develop your product

and process, acquire knowledge, build

your business case

• Global network of centres providing

facilities, machines, post-processing and

engineering support

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Boosting AM productivity and quality

Progression rather than revolution

• Better design for AM with a focus on disruption

• Lower cost AM parts enabling more business cases

• Faster builds

• Cheaper materials

• Higher yields / less waste

• Advanced processing techniques delivering tailored

material properties

• Enhanced process sensing and control

• Reduced reliance on post-process inspection

Thank you

10/06/2019

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