Dipl.-Ing. Kristian Arntz

© WZL/Fraunhofer IPT

Micro milling and laser ablation

Two technologies complementing each other

Dipl.-Ing. Kristian ArntzFraunhofer IPT, Germany

Aachen

22nd November 2011

Seite 1© WZL/Fraunhofer IPT

Overview of tool making activities at Fraunhofer IPT

Development of a platform for micro milling and laser ablation with the enabling technologies

Micro milling

Laser ablation

CAx-process chain

Demonstrator applications for Combined micro machining processes

Outline of the presentation


Process Technology at Fraunhofer IPTFine Machining and Optics

Ultra-precision diamond machining, Precision grinding and polishing, Precision glass molding, FE process simulation, PVD coatings for tools and molds

High Performance Cutting

Multi axial milling, Precision hard milling, Precision hard turning, Modelling and simulation of cutting processes

Laser Machining

Laser beam joining and structuring, Laser-assisted machining, Laser surface treatment, Generative assembly manufacturing, Biotechnology

CAx Technologies

CAx Framework, Development of CAM modules, NC simulation, NC data optization


Laser Materials ProcessingSome of our Highlights

Laser surface treatment Laser beam brazingDesign structures

Laser assisted turning Laser deposition welding

Structures for tribologyWelding of heat exchangers Laser deburring

Laser assisted metal spinning

© Werkzeugbau Akademie

The Tool Manufacturing Academy offers research, consulting and qualification with leading tool manufacturing companies

Source: Summerer, Siebenwurst, Rathgeber

Werkzeugbau Akademie

Research and Development

Processing key aspects based on a development- and research- roadmap

Acquisition of public research funds

Accomplishment of contract research

Qualification

Modular qualification proposals for non-graduates and graduates

Top-class orators from industry and science

Continuous collaboration on future issues in the tool manufacturing industry

Industrial Consulting

Bilateral projects concerning technical and organizational issues

Concept development and project realization

Sample tool manufacturing with a whole process chain and the support of the institutes

© Werkzeugbau Akademie

Increased Level of Technology Performance

Increased Level of Academization

The increasing level of technology and engineering affords the industrialization in the tool manufacture

Source: Audi AG; Deckel Maho Gildemeister; t-mobile;

Industrialization

Synchronization

Process standardization

Product standardization

Focusing & Cooperation

Systematical use of knowledge

Long-termqualification

Enlarged productquality rating

Professionalresearch Systematical use of

knowledge

Long-termqualification

Enlarged productquality rating

ProfessionalresearchTechnology chains

Overall equipment efficiency

Manufacturingtechnology

Investments


Process chain- oriented competency areas in process technology

2,5D –Pre-Processing

3D – GeometryGeneration Surface Finishing (Surfaces-)

Functionalization

Design Structures and Functions

Wear protection

Clamping Systems

High Performance Cutting (HPS)

Hard milling/ Micromilling

High Speed Cutting (HSC)

CAx - Technologies

Material engineering / Metallography

Development/ Construction Acquistion Manufacturing Service/ Marketing/

DistributionAssembling


Laser beam structuring – an innovative process for surface structuring How it started: The challenge of "surface decoration"

Electroforming High manual effort Moderate reproducibility Poor flexibility No consistency of a (digital) data chain Limited material range

Etching High manual effort Poor reproducibility Limited material range Restricted flexibility related to the structure design

A wider scope related to the structure design, the increase of the reproducibility and the reduction of the manual effort require innovative solutions for the surface texturing in the tool and die manufacturing!

© Eschmann Textures

© Galvanoform


Laser beam structuring – an innovative process for surface structuring "Removal rate and surface quality" – process basics

Use of pulsed laser sources – Pico- and nanosecond laser

Ablation with ps-laser (1 picosecond = 10-12 sec)– Material removal by sublimation (multi-photon-

absorption):"Cold" ablation process => no thermal conduction

– Nearly all materials are processable – Removal of a small material volume by a single laser pulse– No melt formation on the surface

Ablation with ns-laser (1 nanosecond = 10-9 sec)– Linear absorption– Predominantly melt ablation:

Thermal process with melt formation– Limited range of processable materials– Removal of a large material volume by single laser pulse– Low-cost laser sources

Fraunhofer IPT


Laser beam structuring – an innovative process for surface structuring Application example "injection mold" – free formed surface

Work piece specification

Injection mold

Basis material 1.2343 (X38CrMoV5-1)

Quenched and tempered to 50 +2 HRC

Laser structured area: 196 mm x 152 mm

Result

Large-scale and seamless surface structuring

– Leather-grain K3A of the Volkswagen Golf VI

– Hybrid-structure with micro- and macro structures

– Geometrically defined pyramid structures

Fraunhofer IPT

Fraunhofer IPT

Fraunhofer IPT

Fraunhofer IPT


Integ-μ Project structure

Platform 1b, led by Fraunhofer IPT, Germany

Research partners IPT, WZL/RWTH, KU LEUVEN Industrial partners KERN, KISTLER, SWATCH, TWT, MT,

LASAG Objectives Development of an integrated machine

tool system for a combined process of micro milling and laser ablation

System programmable through an adapted CAx-platform

Special monitoring systems to provide high reliability in micro milling

The Integ-μ projectDeveloping integrated solutions for micro manufacturing


Targeted performance

multiple machining operations in one workholding configuration

processes will be used to complement each other (feature size, material, time)

stable micro milling process with tool steels > 55 HRC

laser structuring of freeform surfaces with very small feature sizes (12 μm focus diameter)

broad range of applicable materials

Applications and market sectors

Flexible and cost-effective fabrication of micro moulds and micro parts

Novelty and impact on EU industry

Fabrication of high precision complex 3D shapes with

increased flexibility, better accuracy, increased productivity, faster throughput, advanced materials and reduced handling and plant area

Integ-μ Platform 1bMicro milling & laser ablation

Integ-μ Project structure


KERN PyramidNano

Travel X/Y/Z 500/500/400 mm³

Clamping area max. 600 x 600 mm²

Drives and guideways hydrostatic

Workpiece weight max. 250 kg

Feed rate 0.01 - 30,000 mm/min

Acceleration 10 m/s² (1g)

Rotational 360° continuous

Swivelling -20° up to +110°

Precision < 1μm

Weight approx. 8,000 kg

Force measurement system for micro milling

Developed by WZL/RWTH and KISTLER

Source: KERN

Integ-μ Platform 1bMachine tool system for micro milling


KERN EVO Travel X/Y/Z 300/280/250 mm³ Clamping area max. 350 x 230 mm² Workpiece weight max. (3-axis) 50 kg Rotational 360° continuous Swivelling -10° up to +100° Precision < 3μm Weight approx. 3,000 kgLaser system Lumera SuperRapid Wavelength 1064 nm / 532 nm Repetition rate 80 to 1,000 kHz

(200 kHz optimized) Pulse width 10 ps Average output power 17 W / 10W Spatial Mode TEM00 (M² <1.3)Scanner system Scanlab RTC5 Scanlab IntelliScan10 & VarioScan20i

Source: Fraunhofer IPT

Integ-μ Platform 1bMachine tool system for micro laser ablation


Mounting plate with scanner, beam expander and mirrors in place of spindle

Laser source in place of tool changer Laser provides two wavelengths at two

separate outputs, so two beams had to be aligned on one path

Laser control unit Separate industrial PC Connected to machine control

Laser safety Laser-safety windows External clearance Interlock

(connected to machine doors) Emergency shut-off

(Machine & laser source)Source: Fraunhofer IPT

Integ-μ Platform 1bMachine tool system for micro laser ablation – Integration concept


Laser ablation

Several demonstration parts have been realized

Generation of data sheets and storage of process data into "laser tools“


10 mm

5 mm

7 mm

Copper

Tool steel

Graphite



532532532Wavelength of radiation [nm]

500300300Feed speed

[mm/s]

808080Pulse repetition rate [kHz]

776Average laser power [W]

Graphite R 8500

CooperSteel(1.2343)

Integ-μ Platform 1bLaser ablation – process development with first demonstrators


Complete digital process chain

Specialized CAM module for laser ablation

Basic and advances strategies for toolpath planning for the laser ablation process

Seamless integration in NX5 (by using the “CAx framework”)

Stand-alone version possible

Technology and process database

Virtual lasertools

Simulation tools available

Postprocessor

Laser control software “FlexOStruk”

Integrated CAM module for laser ablation

Integ-μ Platform 1bThe software connection: Development of the CAx platform


Machine simulation (KERN Evo with laser integration)

Machine simulation

Simulation of Machine toolpath

Collision detection

Machine kinematics (linkage, offset) is stored in technology and process database

Machine simulation tool can be embedded into host system (NX) with use of CAx framework

Integ-μ Platform 1bThe software connection: Development of the CAx platform


benefitissueprocessa) micro millingb) laser ablation

a

b

a + b (+a)

(a+) b + a

sharpness of corners

weld penetrations (bottom)

weld penetrations (lateral)

-

high material removal rate

sharp corners

sharp corners with high material removal rate (and higher surfacequality by finishig step)

(high material removal rate with) sharp cornersand higher surfacequality

ab

benefitissueprocessa) micro millingb) laser ablation

a

b

a + b (+a)

(a+) b + a

sharpness of corners

weld penetrations (bottom)

weld penetrations (lateral)

-

high material removal rate

sharp corners

sharp corners with high material removal rate (and higher surfacequality by finishig step)

(high material removal rate with) sharp cornersand higher surfacequality

ab

Integ-μ Platform 1bCombined process – test pattern and expected benefit


Integ-μ Platform 1bCombined process – sharp corners


Source: Swatchgroup

Integ-μ Platform 1bDemonstrator part by Swatchgroup: Watch plate


Integ-μ Platform 1bDemonstrator part: Decorative structures with Aachen Cathedral


Decorative pattern

La Perlage / Pearl Pattern

Source: Wikipedia



Pocket (l,w,h): 7 x 1.8 x 2.3 mm³

Slice (l,w,h): 6 x 0.6 x 0.08 mm³



Control of small radius

Control of burr

Control of form, chamfer and burr



Micro milling and laser ablation – complementary technologiesOutlook and vision

Combining powerful micro fabrication technologies can contribute to

reduced processing time by developing intelligent machining and processing strategies

New functionalities by realising adapted and highly sophisticated surface properties

increased quality by realising special features and locally adapted properties

The integration of laser systems in machine tools contributes to

the design of continous process chains including preliminarywork and finishing

Specific setting of local material properties by automaticallycombining different manufacturing processes

Integrated CAx solutions which are able to represent and control whole process chains


Your contact to Fraunhofer IPT

Dipl.-Ing. Kristian Arntz

Head of department Laser Materials ProcessingFraunhofer Institute for Production Technology IPTSteinbachstraße 17, 52074 AachenPhone: +49 241 89 04-121Mobile:+49 174 1902817Fax: +49 241 89 04-6121Mail: [email protected]

Dipl.-Ing. Kristian Arntz

Business

Transcript of Dipl.-Ing. Kristian Arntz