Laser Surface processing -The features and the applications - 1)Introduction 2) Heating process 3) Melting process 4) Laser vaporizing process 5) Laser CVD & PVD 6)laser marking and engraving By Munehary KUTSUNA Nagoya university Kutsuna@numse.nagoya-u.ac.jp
1.Introduction Type of lasers for surface processing High power(45kw) Hig CO2 laser 10kW Nd:YAG laser with lump High power(6kw) diode laser 10kW LD pumped solid state lasers 4kW Disk laser 10kW Fiber laser
Beam Quality of laser beam
Types of Laser Surface processings Laser transformation hardening Laser bending/forming Laser solution treatment Laser alloying Laser cladding Laser surface remelting Laser CVD/PVD
2.Laser transformation hardening
Laser hardening of shaft
Since 1988 by Nissan
Laser hardening of crank shaft for car
Microstructure of harden zone
Hardness distribution ardness Distance from surface
Max.hardness of laser hardening zone
Laser hardening of clutch dram
3, Laser bending/forming
Laser forming of steel pipe Nagoya Univ.
Experimental Setup of laser bending
Bending angle
Why the plate is bended by laser?
Materials properties Is important factor.
Prediction of bending angle
4.Laser solution treatment
5.Laser alloying;carbonizing
Beam rotating device for Surface processing
Carbon distribution
Wear test of laser carbonized zone
Application of laser alloying for aluminum engine for motorcycle
6.Laser cladding
Laser cladding of engine valve seat
Laser cladding of copper alloy powder
Laser cladding of roll embosser
3D Laser cladding using a robot for rapid prototyping and repairing We had an experiment of laser cladding
Optical fiber Powder feeder YAG laser system Powder delivery nozzle Powder delivery nozzle 6-axis robot For x-y-z positioning of focusing lens and powder delivery nozzle Shielding gas cylinder
Laser Two beam circular cones of copper Focus lens Center shielding gas were coaxially assembled. Outer shielding gas Powder flow Clad layer Base metal Fig. Photograph of laser cladding system
Table. Chemical composition of filler metal, SUS304 stainless steel Chemical composition, mass% C Si Mn P S Ni Cr Fe 0.08 0.72 1.54 0.024 0.018 8.75 18.42 bal. Table. Chemical composition of base metal, SM400B Chemical composition, mass% C Si Mn P S Fe 0.18 0.40 1.38 0.017 0.0045 bal.
Laser power Spot diameter Defocusing distance Center shielding gas Outer shielding gas Travel speed Powder Flow Rate 100 W(1ms, 90pps) 1.6 mm +1mm Ar : 10 ltr/min Ar : 10 ltr/min 1.5 7.5 mm/sec 5.6 9.6 and 12.8 g/min with Ar gas
A B C
0.6 50 Thickness of clad layer, mm 0.5 0.4 0.3 0.2 0.1 0 Optimum region 0 2 4 6 8 40 30 20 10 0 Dilution, % Travel speed, mm/sec
Average: 220 Hv ~ 240 Hv
Colmonoy No.5 FP160) Table. Chemical composition of filler metals Chemical composition, mass% C Si Fe Cr B W Co Ni Colmonoy No.5 0.65 3.75 4.25 11.5 2.50 bal. FP160 1.80 21.0 3.0 5.0 bal.
Laser power Spot diameter Defocusing distance Center shielding gas Outer shielding gas Travel speed Powder Flow Rate 100 W(1ms, 90pps) 1.6 mm +1mm Ar : 10 ltr/min Ar : 10 ltr/min 1.5 4.5 mm/sec 8.42, 12.67 g/min; Colmonoy No.5 4.67, 9.39 g/min; FP160
(a) Colmonoy No.5 (b) FP160
(a) Travel speed = 1.8 mm/sec (b) Travel speed = 4.5 mm/sec
(a) Travel speed = 2.25 mm/sec (b) Travel speed = 3.0 mm/sec
(a) Colmonoy No.5 (b) FP160
Multi pass cladding for rapid prototyping Laser beam powder x Scanning direction Layer by layer Scanning pattern
Schematic drawing Photograph of multi layer cladding
7.Laser surface remelting
Dull treatment by laser
Dull treatment for cladding of roll
8.Laser CVD/PVD
Laser CVD for circuit
Laser PVD for tools
attention