Process and Machine Technology for Micromachining and Surface Texturing of Complex Products. Max Groenendijk

Transcription

1 Process and Machine Technology for Micromachining and Surface Texturing of Complex Products Max Groenendijk 1

2 Company Introduction Spin-off company from University of Twente and M2i Institute, founded in 2008, active in Ultrashort Pulsed Laser Materials Processing Offering: Machines for Production and R&D Process and Application Development Job Shop Production Specialist in Surface Texturing on 3D curved Surfaces 2

3 Outline There are many applications for < 100 W lasers combined with galvo-scanner beam deflection Still a lot of development is needed towards exploiting the full potential of such applications High-precision, complex processes need better control (software) Micromachining Examples Functional Surface Texturing 3D Texturing Technology Machine Technology and Control Software 3

4 Microdrilling Hole diameters down to 1!m Control on shape: funnel, conical, (nearly) cylindrical 4

5 hardmetal Micromilling Direct write, software controlled geometries Machining of all materials: Hard: SiC, hardmetal etc. Delicate: polymers, membranes, very thin... 2,5D profiling / 3D products 5

6 Processing Efficiency Micromilling of hardened steel Best efficiency around 1 J/cm 2 peak fluence Only high reprates (here 6 8 MHz) can use full laser power High scanning speeds are needed > good control on sky-writing is essential 6

7 Micromachining Alumina Round pockets ø 12,5 mm Depth 20!m +/- 0.5!m (+/- 2.5%) Very sensitive material 1% variation of laser power results in ~ 10% variation in pocket depth Inherent depth variations across a machined pocket are too large Depth variations reproduce 7

8 On-the-fly correction Measure the depth variations Generate background map Adjust laser power on-the-fly during machining Significant reduction of inherent depth variations What you need: Fast modulation of laser power Ability to implement this strategy in your control software 2!m peak to valley error map 0,7!m peak to valley 8

9 Functional Surfaces Textures From engine parts to skin comfort Manipulation of light Manipulation of cell adhesion 9

10 Wetting Properties! m Partial wetting High speed recording Milk-ophobic Super hydrophobic and hydrophillic surface 10

11 Tribological Properties Three functions of dimples: 1. Pressure build up 2. Oil reservoir 3. Wear Particle Trap 11

12 What textures can we make with USP lasers? 12

13 LIPSS Regimes Laser induced periodic surface structures 1. Nanospheres 2. High spatial frequency LIPSS (parallel to laser polarization) 3. LIPSS (perpendicular to laser polarization) Source: M2i TULP project, Jozef Obona 13

14 Nanostructures by LIPSS 14

15 Cone like protrusions (CLP) Stochastic textures in steel: typical sizes and spatial frequency can be controlled by laser process 15

16 Microstructures 16

17 Molded Textures Micro- nano textured steel mold surface Replication of micronano texture in injection molded polymer (INJECTION) MOLDING 17

18 3D Texturing Machine 3D Laser Micromachining and Texturing Machine Picosecond pulsed laser, 5 axes + galvo Scanner 18

19 Tiling of Surface Step and Scan Approach 19

20 Texture Generation Dimple patterns with a specific density are generated 20

21 3D texturing test 21

22 Result Functional surface texture Tiles visible due to the regular dimple packing Marked outlines of the tiles 22

23 Texturing Mirror Cup Mould FP7 project Nanoclean Demonstrator: Injection mold for car mirror cap Goal: obtain a superhydrophobic effect 23

24 Tiling - Meshing Remeshed surface CAD generated STL surface description 24

25 Mold texturing 25

26 Injection molded mirror cups 26

27 FP7 Project APPOLO Development of technology for soft-touch surfaces in car interiors Our pillar textured surfaces exhibit a silky smooth touch Reduced friction due to largely reduced skin contact area Optimization of machine and further development towards industrial use of technology 27

28 Machine Technology Goal: realize the full potential of ultrashort pulse laser micromachining Processes can get complex Processing strategies need to be well defined High degree of control on processing parameters Users should concentrate on process, not on machine specific details (like scanner delays, manual calibrations and power measurements) Demands for high level of integration / automation Demands for advanced control software 28

29 Control Software Specifically designed for step-and-scan laser micromachining High level and machine independent programming Structured job definitions, written in general-purpose object-oriented programming language (Python) Graphical preview and inspection tool (verify geometry AND parameters) Flexible: Very large and complex jobs are possible But it is also easy and fast to compose a simple experiment tiles, 30 million dimples 29

30 Details Handled Automatically No worries about machine specific details, but focus on the process Automatic and exact timing for accurate sky-writing (correct delays set automatically) Calibration system for scanner auto-alignment Automatic power calibrations: program the machine in watts (instead of percent) High resolving off-axis camera for accurate workpiece alignment and calibration 30

31 Modular Micromachining System Flexible and highly accurate workstation for micromachining and surface texturing Ideal for R&D, flexible high-tech jobshops, process development Can be customized into single purpose production machine Standard system launched in summer 2014 Reproducible results by: Use of proven high quality components Handle machine specific details Automated calibrations and power measurements 31

32 Thank you for your attention Max Groenendijk Lightmotif B.V. Pantheon PR Enschede Tel: +31 (0)