machni ni g technool gy of r aerospace and auto parts ... technology for aerosp… · professor,...
TRANSCRIPT
Machining Technology for Aerospace and Auto Parts Manufacturing
Auto Parts Tech Day 2017August 8-10, 2017
Thailand Science Park (TSP)Pathum Thani, Thailand
------------------------------------------------
Toshiyuki ObikawaProfessor, Manufacturing Research Center, Tokyo Denki University
Emeritus Professor, The University of TokyoEmeritus Professor, Tokyo Institute of Technology
Member of Science Counsel of Japan
1
> Aircraft industry and its manufacturing research and development
> Machining of airframe partsR & D at the University of Tokyo
> High speed machining; You should not reduce cutting speed.
> High pressure coolant technology: cost-effective machining
> Summary
Overview
2
Aircraft production in the world
3
Forecast of jet aircrafts from 2012 to 2031 (Source: Japan Aircraft Development Corporation)
> Commercial aircraft industry is expected to grow at 5% annually.> New 39,620 airplanes, valued at $5.9 trillion will be delivered by 2035.
Number of aircrafts Number of seats
> 400
310 - 400
230 - 309
170 - 229
120 - 169
100 - 119
60 - 99
20 - 59
ForecastActual
New airplanes
Retained airplanes
Aircraft production in Japan
4
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Total
Commercial
DefenseProd
uctio
n va
lue
Year
[100 million yen]
Production value of airplanes (airframes and engines) in Japan [in 100 million yen] (Source: Aerospace Industry Database, The Society of Japanese Aerospace Companies, 2017)
13,030
18,000
16,000
14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
> Production value of commercial airplanes in Japan sharply grows from 2011 to 2015.> Innovative high-efficiency manufacturing processes are needed to meet the rapid
increase in the amount of production.
787
Global research centers
5
Rolls Royce The Manufacturing Technology Centre (MTC) 2011-(1) Universities of Nottingham, Birmingham and Loughborough, and TWI(2) High integrity joining, intelligent automation, powder net shape manufacture, etc.(3) Rolls-Royce, Airbus & Aero-Engine Controls, etc.
The Commonwealth Center for Advanced Manufacturing (CCAM) 2012-(1) University of Virginia, Virginia Tech and Virginia State University(2) Surface engineering, advanced manufacturing systems and related technologies(3) Rolls-Royce, Newport News Shipbuilding, Canon, Sandvik Coromant, etc.
The Advanced Remanufacturing & Technology Centre (ARTC) 2013-(1) Singapore Institute of Manufacturing Technology (SIMTech), A*STAR(2) Repair and restoration, surface modification & product verification(3) Rolls-Royce, Boeing and Siemens
The Advanced Manufacturing Research Centre (AMRC) 2001-(1) The University of Sheffield(2) Machining, Metrology, Assembly, Composite material, Design & Prototyping, etc.(3) Rolls-Royce (“Factory of the Future” was open in 2008), Boeing, Airbus, etc.
The National Composites Centre (NCC) 2011-(1) University of Bristol(2) Advanced composites design, structural analysis, modelling and simulation, etc.(3) Rolls-Royce, Airbus, GKN, Agusta Westland, Umeco, etc.
The Advanced Forming Research Centre (AFRC) 2011-(1) University of Strathclyde(2) Forming and forging of metals, materials characterization and process modelling(3) Rolls-Royce, Boeing, Aubert & Duval, Barnes Aerospace, etc.
The Nuclear Advanced Manufacturing Research Centre (Nuclear AMRC) 2012-(1) Universities of Sheffield and Manchester(2) —(3) EDF, Areva, Rolls-Royce, Sheffield Forgemasters International Ltd, etc.
AMRC with Boeing, Rolls-Royce Factory of the Future
Boeing12 global research centers out of the US.
ARTC, SIMTech & A*STAR, Singapore2013 -
CMI, the University of Tokyo, Japan2013 -
Research funds: partner companies, governments, funding agencies
Collaborative Research Center for Manufacturing Innovation (CMI), Institute of Industrial Science, the University of Tokyo
6
CFRPEf
ficie
ncy
and
Econ
omic
sInnovative Manufacturing
Technology of Aircrafts
High value manufacturing
SustainabilityIntelligence
and Flexibility
NDI - CFRP parts
Hot forming & Welding- Titanium alloy
High speed machining - CFRP- Titanium alloy- Al-Li alloy
Robotics- Sealing- Milling
Members of CMI> Academia
Institute of Industrial Science, the University of Tokyo
> Aircraft (4)Boeing, Mitsubishi Heavy Industries, Kawasaki Heavy Industries, SUBARU
> Machine tool (1)DMG MORI
> Cutting tool (5)Sandvik Coromant, OSG, Sumitomo Electric Hardmetal,
Mitsubishi Material, NACHI-FUJIKOSHI> Material and Cutting fluid (3)
TORAY, Kobe Steel, Idemitsu Kosan> Small and medium companies (12)
Consortium for Manufacturing Innovation
7
> Aircraft industry and its manufacturing research and development
> Machining of airframe parts: R & D at the University of Tokyo1. Drilling of CFRP2. Pocket milling of titanium alloy and aluminum alloy3. Machining of Al-Li alloy
> High speed machining; do not reduce the cutting speed
> High pressure coolant technology: cost-effective machining
> Summary
Overview
8
9
Drilling of carbon fiber reinforced plastic (CFRP)> CFRP is used for Boeing 787 up
to 50 wt%. > Tremendous number of holes
are made on CFRP plates for joining during assembly processes.
> CFRP is one of difficult-to-machine materials because a carbon fiber has a very high strength, about 10 times higher than steel.
> Troubles in drilling CFRP:delamination, uncut fiber,spalling, uncut resin, burn, rapid tool wear
http://articles.sae.org/5907/
http://www.carbonfiber.gr.jp/field/images/plane02_b.jpg
10
Drilling of CFRP (2)> Optimization
Tool geometryTool material, coating material (diamond coated drill)Drilling conditionsDrilling method (axial drilling or orbital drilling) for large holes and stack plates
Drill geometry for reducing thrust force and avoiding delamination at tool exit.Drill geometry may change position to position when the thickness of CFRP and the hole diameter to be drilled are different.
Orbital drilling Orbital drilling machine
http://www.makotoloy.co.jp/kougu.html
(Helical milling) http://www.novator.eu/products/portable-orbital-drilling-systems__73http://www.novator.eu/
11
Drilling of CFRP (3)> Prediction system based on the energy approach for optimizing drilling processes> Chip formation, chip flow direction, cutting forces (thrust and torque), cutting
temperature, tool wear, delamination at the exit hole are predicted in about 10 min.
Prediction system of axial drilling, (end milling and orbital drilling) of CFRP
High Speed Machining Technology Development of Difficult-to-Machine Materials for Aircraft (FY2015), published by the New Energy and Industrial Technology Development Organization (NEDO), Japan
12
Drilling of CFRP (4)
> Calculated results for axial drilling
Drilling forces
Drill wearSizes of delamination
High Speed Machining Technology Development of Difficult-to-Machine Materials for Aircraft (FY2015), published by the New Energy and Industrial Technology Development Organization (NEDO), Japan
13
(a) 124 sec (b) 248 sec (c) 372 sec (d) 496 sec
> Drilling of stack plates of CFRP and titanium alloy is one of difficult jobs.> High cutting temperature during drilling titanium alloy may cause the burn
of CFRP.> Prediction of cutting temperature in drilling the stuck plates is useful for
determining drilling conditions.
Drilling of CFRP (5)
Temperature in drilling pre-holed stack plates of Ti/CFRP/Ti
High Speed Machining Technology Development of Difficult-to-Machine Materials for Aircraft (FY2015), published by the New Energy and Industrial Technology Development Organization (NEDO), Japan
14
> Drastic increase in the amount of titanium alloy used for CFRP aircrafts> Certain amount of aluminum alloy is replaced by titanium alloy to avoid
High speed pocket milling of titanium alloy
Others
Composite materials
Titan
Steel
Aluminum
Changes in structural materials of Boeing’s aircraft(Source: The society of Japanese Aerospace Companies)
1. Galvanic corrosion due to the difference of electric potential between aluminum alloy and CFRP
2. Large thermal deformation due to the difference of linear expansion coefficient between aluminum alloy and CFRP
> Titanium alloy to be machined787: 90-120 ton (Mid-size aircraft)777: 60-70 ton A380: 80 ton
*About 85% of titanium are removed as chips during machining process, e.g., 100 ton 15 ton.
2. Pocket milling with minimum mismatch or free from mismatch
3. Environment friendly machining:High speed machining using mist coolant promoting lubrication and cooling as well as reducing thermal impact to an end mill.
15
> New strategies for high efficiency pocket milling with reduced cost
High speed pocket milling of titanium alloy (2)
1. Pocket milling with minimum hand finishing or free from hand-finishing Rough machining finish machining hand finishing
Rough machining finish machining
Mismatch is a step on the machined surface, larger than 25 µm (1/1000 inch), caused between machining processes.
16
High speed pocket milling of titanium alloy (3)
Achievement (evaluated by operation time)
~30%
50%
~90%
> Achievement(evaluation by operation time)1. Finish machining technology without mismatch has
been established.Hand finishing: reduction by 50%.
(Hand finishing except pocket milling area is needed)Finish machining: reduction by about 90%.
2. Rough machining: reduction by about 30%.3. Total time: reduction by about 50%.
> Pocket milling for evaluating new machining method
High Speed Machining Technology Development of Difficult-to-Machine Materials for Aircraft (FY2015), published by the New Energy and Industrial Technology Development Organization (NEDO), Japan
Chip removal up to 500 cc/min
High efficiency rough milling of titanium alloy 5-axis rough machining of Ti-6Al-4V by Makino Milling Machine
http://www.makino.co.jp/jp/processing/parts/07.html
- 5-axis machining center with high torque at low rotational speed
- Roughing end mill 80 mm in diameter with five flutes
- Spindle speed in machining: 240 min-1
(cutting speed 60.3 m/min)- Fees speed 144 mm/min- Axial depth of cut 80 mm- Radial depth of cut 20 mm - Chip removal rate 230 cc/min
Tool life is around 60 min.
17
18
High speed pocket milling of titanium alloy (4)
30 mm for titanium alloy Ti-6Al-4V
50 mm for aluminum alloy 7075
> Depth of cut without chatter vibration in milling pockets with 3 mm-thick thin walls:
High Speed Machining Technology Development of Difficult-to-Machine Materials for Aircraft (FY2015), published by the New Energy and Industrial Technology Development Organization (NEDO), Japan
Titanium alloy Ti-6Al-4V
aluminum alloy 7075End mills tested
19
Machining of Al-Li alloy> Large distortion of Al-Li alloy after machining
Size of distortion: Al alloy < Al-Li alloy < titanium alloy1. Thermal conductivity: Al-Li alloy < Al alloy
→ High cutting temperature in machining Al-Li alloy.2. Large residual stress generated by machining
In case of thin plate cutting, generally,residual stress by machining is larger than that by rolling.
3. Adhesion is stronger for Al-Li alloy than Al alloy.4. Reforming Al-Li work after machining and lower cutting speeds increases the cost
of machining.
Ti-6Al-4V (GE Aviation)
> Elimination of distortion is one of most difficult themes in cutting technology.> Application of FEM expects to clarify cutting phenomena and the mechanism of
residual stress generation.> Milling experiments and measurement of residual stresses with X-ray Residual Stress
Analyzer
20
Machining of Al-Li alloy (3)
> Achievement1. Distortion was reduced by more than 30%.2. Finite element method has been established for evaluating the distortion of Al-Li thin plate.
Flank wear
Small
Large
OptimizedNot optimized
Geometry of cutting edgeD
efor
mat
ion
Reduction of distortion
Reduction of deformation
Reduction of residual stress by tool geometry optimization ( FEM analysis)
Optimized tool geometry
Conventional tool geometry
High Speed Machining Technology Development of Difficult-to-Machine Materials for Aircraft (FY2015), published by the New Energy and Industrial Technology Development Organization (NEDO), Japan
> Aircraft industry and its manufacturing research and development
> Machining of airframe parts: R & D at the University of Tokyo
> High speed machining; You should not reduce cutting speed.
> High pressure coolant technology: cost-effective machining
> Summary
Overview
21
High speed turning of cast iron with CBN tool
22
> Tool life curvesby K. Karino
Tool life
Cutt
ing
spee
d
Work: Gray cast iron FC250, 148HBTool: Poly-crystalline cBN (MB730), SNGN120408Tool holder: CSBNR2525M43Cutting conditions: ap = 0.50 mm, f = 0.10 mm/rev
Tool life criterion:Width of flank wear VB = 0.3 mm
Tool wear mechanism (1)
23 THC Childs et al., Metal machining, Arnold (2000)
Cutting temperatureOptimum temperature
Wea
r rat
e> Strong adhesive wear of a tool changes the strategy of selecting
cutting speed.
Machining of hood mold
http://www.marubeni-sys.com/de/gom/jirei/atos_rf02.html
> A large hood mold is usually made of ductile cast iron.Its finishing requires long time and change of ball end mills several times due to tool wear.
24
High speed milling of hood mold using CBN radius end mill
(1) Tool life extensionTiAlN ball end mill CBN ball end mill
(2) Increase in cutting speedCBN ball end mill CBN radius end mill
Work: FCD540
Tool life cutting length [m]
cBN tool
Cutt
ing
spee
d [m
/min
] TiAlN: tool life curve
CBN ball end mill
CBN: tool life curve
Tool life extension
by N. Sunahara
Tool life cutting length [m]
Cutting speed
Cutting speed [m/min]
CBN radius end mill increases cutting speed
CBN ball end mill
CBN: tool life curve
25
Hard turning using CBN insert
http://www2.coromant.sandvik.com/coromant/pdf/Hard_part_turning/C-1040-069.pdf
26
> Turning of hardened steelChip color indicates that the cutting temperature is very high.Coolant except high pressure coolant should not be applied to avoid thermal shock to the insert.
Hard turning of AISI52100 (HRC62) with CBN tool by Egawa
27
> The optimum cutting speed with the minimum wear is 80 - 100 m/min.> Serrated chips are formed under the optimum cutting speeds.
(a) Width of flank wear (b) Chip formationCutting conditions: depth of cut 0.15 mm, feed rate 0.10 mm/rev, Dry
Cutting speed 15 m/min Cutting speed 50 m/min
Cutting speed 75 m/min Cutting speed 150 m/minCutting speed
Wid
th o
f fla
nk w
ear
: Position of maximum chip thickness
: End cutting edge
Cutting length 600 m
Tool wear mechanism (2)
28
Critical speed
Cutting speed
Serrated chip
Tool
life
cut
ting
leng
th
Flow type chip
> Change in chip formation from flow type chip to serrated chip may reduce the chip load to extend the tool life.
Cutting temperature in hard turning
29
> Change in cutting temperature with work hardness by N. NarutakiCutting temperature reduces when steel is harder than HRC50.
Cutting temperature in hard turning (2)
30
> Cutting temperature begins to reduce when the serrated chips are formed.
Chip formation obtained by N. Narutaki
Hard skiving
31
> New machining technology of hardened steel using a long straight cutting edge of CBN tool developed by Sumitomo Electric Industries, Ltd.Feed marks do not remain on the machined surface.
https://www.youtube.com/watch?v=d_fVuSyMHZE
> Work: AISI4I35(HRC60)
> Tool:CBN with Straight long edge
Video:
Hard milling of pre-hardened steel by Takeoka
32
> Work: SKD61(HRC35)> Tool: Ball end mill, TiAlN coated carbide,
2 mm in diameter
Cutting conditions: ap 0.5 mm, ae 0.5 mmCutting speed is 163 m/min at tool rotational speed 30,000 min-1.
Spindle rotational speed [min-1]
Tool
life
cut
ting
leng
th [
m]
Feed speed [mm/min]
Tool
life
cut
ting
leng
th [
m]
Influences of spindle speed and feed speed on tool life cutting length
Milling of Inconel 718 by Takeoka
33
Ad
Ad:軸方向切込み量Rd:径方向切込み量
Ad : 0.30 mmRd : 0.50 mmFz: 0.15mm/tooth
Tool diameter 6 mm
Relationship between cutting speed and cutting length
> When finishing, long cutting distance (feed distance) was achieved.> Tool: Ball end mill, TiAlN coated carbide,
2 mm in diameter
Turning of Inconel 718 with whisker reinforced ceramic
34
300 360 420 480 540 600 660 720 7800
500
1000
1500
Cutting speed [m/min]
Tool
life
leng
th [m
]
Cutting conditions: SiC whisker reinforced alumina, depth of cut 0.3 mm, feed rate 0.1 mm/rev, wet
Ball end milling of Ti-4Al-4V
35
Cutting conditions: cemented carbide ball end mill with nose radius of 1 mm, ap = 0.5 mm, ae = 0.5 mm, feed rate 0.02 mm/tooth
30 60 90 120 150 180 210 240
0.02
0.04
0.06
0.08
0.10
0Cutting speed [m/min]
Wid
th o
f wea
r V
Bm
ax [m
m]
Cutting conditions: Coated flat end mill, ap = 1mm, ae = 1mm, fz = 0.03 mm/tooth
Maximum width of flank wear against cutting speed
Maximum width of flank wear against tool rotation (by Anzai)
> When finishing small parts such as implants, watch parts, with small depths of cut,cutting speed should be increased.
> Aircraft industry and its manufacturing research and development
> Machining of airframe parts: R & D at the University of Tokyo
> High speed machining; You should not reduce cutting speed.
> High pressure coolant technology: cost-effective machining
> Summary
Overview
36
Effects of high pressure coolant (HPC)
37
Cleaning of machined surface & tool face
Deburring
+
High pressure coolant at a glanceKennametal BeyondBLAST
- Extended tool life- More effective for higher cutting speed- Small nozzle for increasing coolant pressure
Inserts with coolant channel
http://www.triconmetals.com/images/repositories/PDFs/JA_A-10-02469JA_Innovations2012.pdf
Coolant pressure:7 MPa(1000 psi)
38
Coolant pressure:0.7 MPa(100 psi)
Classification of chip shape (INFOS)
Classification into 11 shapes.Needle chip (type 11) is added to 10 types in the right figure.
K. Nakayama: J.JSPE, 42, (1976) pp. 74-80. 39
bad
goodpermissible
(Ribbon chip)
(Tangled chip)
(Flat spiral chip)
(Spiral chip)
(Long tubular spiral chip)
(Short tubular spiral chip)
(Coiler spiral chip)
(Coil chip)
(Short coil chip)
(Shredded chip)
Relationship between chip type number and coolant pressureTitanium alloyNickel base superalloyStainless steel
breaking) (3) High pressure coolant (chip
40T. Obikawa, et al., Seisan Kenkyu,(2015)
Video:- Hole diameter: 6 mm- L/D: 72- Large wedge angle- Feed speed: 637 mm/min
Effects of high pressure coolant- High speed drilling- Pecking is not needed- High L/D ratio
http://www.youtube.com/watch?v=0Byx0F-yXgc&feature=youtu.be
41
High pressure coolant (drilling)
L/D ratio: length to diameter ratio of a hole
Cost effectiveness- largest for drilling
Cost effectiveness of high pressure coolant
42
Cost reduction depends directly on the machining operation. > I.M.: Milling with end mill with inserts> E.M.: Milling with solid end mill> Drill: Drilling
- Work: Ti-6Al-4V - Pressure of HPC: 7MPa- Pecking during drilling is
not used for HPCused for low pressure coolant
M. J. Bermingham, 2014, Int. J. Adv. Manuf. Tech., 72, pp. 77–88.
New tool holder for high pressure coolant
Jet-tech method Jet-tech holder
43
L shape nozzle
Tool flank
Tool life
44
SUS304 Inconel 718
Tool wear evolution
Cutting conditions: cutting speed 300 m/mindepth of cut 1.0 mm, feed rate 0..2 mm/rev
44
Cutting conditions: cutting speed 150 m/mindepth of cut 0.3 mm, feed rate 0.1 mm/rev
> Aircraft industry and its manufacturing research and development
> Machining of airframe parts: R & D at the University of Tokyo
> High speed machining; You should not reduce cutting speed.
> High pressure coolant technology: cost-effective machining
> Recent hot topics of machining in JapanGear skiving for dramatic reduction in gear cutting time
> Summary
Summary
45
Thank you
46