State Key Laboratory in Ultra-precision Machining Technology
超精密加工技術國家重點實驗室
Diamond milling servo based mechanical machining system for micro/nanomanufacturing Zhiwei Zhu Supervisor: Dr. Sandy To, State Key Laboratory of Ultra-precision Machining Technology, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong SAR, China. E-mail:
[email protected] 1/50
State Key Laboratory in Ultra-precision Machining Technology
超精密加工技術國家重點實驗室
Outline Background Literature review Main research work
Part I: Diamond milling servo based machining system • Application for the generation of Microlens Array • Bi-axial DMS for active control of surface nanotextures • Intersecting DMS for hierarchical micro/nanostructures • A combination of the intersecting and bi-axial DMS
Part II: Rotary vibration assisted diamond milling servo • Mechatronic design of the rotary vibration system • RV-DMS for the generation of micro/nanostructures • RV-DMS for micro/nanomachining of brittle materials
Overall contribution and future work 2/50
State Key Laboratory in Ultra-precision Machining Technology
超精密加工技術國家重點實驗室
Background a
c
d
Microlens array Backlight diffraction based 3-D glass-free display After: D Fattal et al. Nature 495, 348-351 (2013)
After: Li and Yi, Appl Optic, 51: 1843-52 (2012) Yi et al. Optic Express, 21: 22232-45, (2013) Song, et al. Nature 497(7447), 95-99 (2013)
3/50
State Key Laboratory in Ultra-precision Machining Technology
超精密加工技術國家重點實驗室
Background
Characteristics of the shark skin After: L Wen et al. J. Experimental Biology 217(10): 1656-66 (2014).
Artificial and natural nanostructural colour After: F. Cheng et al. Scientific reports 5 (2015) http://www.nanotypos.com/portal/portfolio/structural-color-generation/
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Background Attacus atlas moth eye
Typical fabrication methods: Bottom-up methods: Self-assembly Two-photon polymerization Top-down methods:
Lithographic techniques Chemical based processing
• material limitation; low efficiency; • flat surface; low structure accuracy. D. Ko, et al. Soft Matter 7, 6404-6407 (2011)
Mechanical machining Diamond micro/nanomachining 5/50
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Literature review Motion based direct cutting Fast-/slow-tool-servo (F-/STS)
Nano-FTS
After: Li and Yi, Optics letters 30: 1707-1709 (2005) Scheiding, Yi et al. Optics Express 19: 23938-51 (2011) F Fang, et al. Optics Express, 16(10), 7323-7329 (2008). After: E. Brinksmeier et al. CIRP Annals, 59(1), 535-538 (2010).
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Literature review Motion based direct cutting
Ultrasonic elliptical vibration based micor/nanosculpturing After: Suzuki et al. Precis Eng, 35 (1): 44-50 (2011).
Elliptical vibration based Ultramill After: T. A. Dow et al. In: ASPE Spring Topic, (2007).
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Literature review Micro/nanopatterned tool printing
Tool Tip Diamond Tool
Micro-patterned cutter by grinding in milling After: J. Xie et al. CIRP Annals, 64(1), 101-4 (2015).
Nanopatterned diamond tool by FIB in turning After: X. Luo et al. J Micromech Microeng, 22, 115014 (2012).
8/50
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Literature review Tertiary motion modulation
Ultrasonic elliptical vibration Texturing After: P. Guo et al. CIRP Annals, 63(1), 553–556 (2014). Guo and Ehmann, Int J mach Tool Manuf, 64: 85-95 (2013)
Rotary ultrasonic Texturing After: Shao, Int J mach Tool Manuf, 86: 12-17 (2014)
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State Key Laboratory in Ultra-precision Machining Technology
超精密加工技術國家重點實驗室
Objectives The overall objective is to develop an innovative diamond cutting based micro/nanomanufacturing system for flexible generation of the microstructured and hierarchically micro/nanostructured surfaces, accordingly extending the applications of the structures in a variety of related fields. To propose and comprehensively investigate a micro/nanomanufacturing system, namely the Diamond Milling Servo (DMS), based on optimal combination of the concepts of diamond raster milling and fast- or slowtool-servo diamond turning; To develop Computer-Aided-Manufacturing (CAM) system for the DMS based mechanical machining as well as the practical mechatronic system for the implementation of the DMS.
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Part I: Diamond milling servo based machining system Basic principle of the DMS system Basic Features:
Y X
Operating in the Cartesian coordinate system with constant rotation distance of the diamond tool, accordingly the constant cutting velocity; Constant angle sampling strategy also results in constant arc length in the machined surface;
Y X
Interrupted nature of the cutting process enables sufficient cooling of the diamond tool, being beneficial for extending tool life.
Configuration of the DMS System, (a) hardware configuration, (b) the horizontal cutting and (c) the vertical cutting.
11/50
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Part I: Diamond milling servo based machining system (a) Application for the generation of Microlens Array Main Challenges in F-/STS turning of MLA: Azimuth sampling conflicts. Numerous sampling points are required to reduce the position dependent interpolation error; Too many controlling points in one revolution will significantly reduce the spindle speed; The volume of required toolpath data is often too large to be easily operated by the control system. Tracking bandwidth limitation. Cutting operation cannot always keep working in its optimal dynamic status during cutting; Phase-lag effects of the servo system dependent on the working frequency lead to poor form accuracy of each lenslet as well as distortions of the whole array.
Typical microlens array After: Hung et al. Optical Eng, 46(4), 043402. (2007).
Summary: Inconsistence! 12/50
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Part I: Diamond milling servo based machining system (a) Application for the generation of Microlens Array Uniqueness and solutions to the challenges The constant cutting velocity, consistent arc length sampling, and consistent tracking bandwidth in any cutting revolution can be achieved deriving from the intrinsic constant rotational distance, thereby, leading to the homogeneous quality of the machined MLA. For the planar MLA, it can be subdivided into several basic lens array cells due to its rigid periodicity. By repeating cutting of a basic cell, the computational costs as well as the volume of data file of the toolpath can be significantly reduced. Accordingly, the whole MLA with arbitrary size can be uniformly achieved. 13/50
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Part I: Diamond milling servo based machining system (a) Application for the generation of Microlens Array Cutting parameters Materials Rotation radius Rd Inclination angle α Spindle speed S Feedrate fx Sampling number Ns Tool nose radius Rt Tool rake angle γ0 Workpiece dimension Basic cell dimension
Brass C2600 2.3448mm 3.891o 13 rpm 2.5μm/rev 1800 0.104mm 0o 5010mm2 2.52.5mm2
The aspheric lenslet z ( x, y)
sCRo 2
-
sC 2 ( x, y)
4 4 1 (1 k )C 2 Ro 2 4 4 1 (1 k )C 2 2 ( x, y)
With Curvature C Micro-asphere radius R0 Conic constant k Shape parameter s Height of each leaslet h Distance between successive lenslets
0.8 mm-1 0.1 mm -0.6 1 4 μm 0.25 mm
14/50
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Part I: Diamond milling servo based machining system (a) Application for the generation of Microlens Array (a)
μm
(a)
2.0
1.5
1.0 0.5
0
0
0
(b)
1
(c) (c)
15
10
5. 18
.1 8
19
-0.5
0
Y:
1200 1500 1800 2100 2400 2700 3000 3300 3600 μm
900
10
600
0
μm
-1.0
95
300
15
0
X: 1
0
μm
50
-2
-3
50
μm
0 -1
-1.5
μm 0 0
20
30
0
.9 4 94
0
0
4.039μm
μm
0 -1 -2 100
150
200
250 μm
300
350
400
450
500
2
(c)
2 1
1
-1 -100
Des. Exp. Error
4
0
0
-3 50
z / μm
50
45
(d)
125.316μm
5
z / μm
20
0
10
40
0
0
:4
15
35
0
0
μm
30
0
0
25
μm
0
25
4 .9 94
125.316 μm
(b)
3
3
X
4 Y:
4
1
0
Des. Exp. Error
35
0
0
15
40
0
0
45
10
0
50
5
-50
0 x / μm
50
100
-1 -100
-50
0 y / μm
50
100
4.039 μm
15/50
State Key Laboratory in Ultra-precision Machining Technology
超精密加工技術國家重點實驗室
Part I: Diamond milling servo based machining system (b) Bi-axial DMS for active control of surface nanotextures
Periodic tool mark enhanced scattering After: Dumas, et al. SPIE (2005)
Hybrid microoptics for multifunction integration After: Malinauskas, et al. J Optic, 12(12), 124010 (2010)
16/50
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Part I: Diamond milling servo based machining system (b) Bi-axial DMS for active control of surface nanotextures
(b)
-3
z / mm
1
x 10
Surface profile Tool edge data3
0.5
5 0
Side feeding
x 10
Bi-axial strategy for tool mark control
-4
-0.02
fi+1 fi fi-1 Tool loci
0
0.02
Spindle side-feeding
Rd y v
0 -0.03
-0.02
-0.01
0 0.01 y / mm
0.02
hp =Rt Rt 0.25 f
Orbital transfer zone Cutting zone
2
Otherwise hp =
Rt
2
2
x
0.03
if 2
o
2
f f Rt 2 2 2
Actively control of the residual tool marks to be functional secondary nanostructures by changing the side-feeding motions;
The feeding changing operation in the OTZ had no impacts on surface generation. 17/50
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Part I: Diamond milling servo based machining system (b) Bi-axial DMS for active control of surface nanotextures Primary surface
F-theta freeform surface
Sinusoid grid micro-structures
Surface features Rotation radius Spindle speed Feedrate*
z(x,y)=ax2+by2+cy4 a=-110-3, b=-110-4, c=3.6810-6. 22.3108 mm 40 rpm random
Tool nose radius Tool rake angle
104 μm 0o
z(x,y)=Axsin(2πfx)+Aycos(2πfy) Ax=Ay=0.5μm, fx=fy=13.33/mm. 1.1648 mm 13 rpm fs=1 μm/rev fg=2.8 μm/rev 5 μm 0o
18/50
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Part I: Diamond milling servo based machining system (b) Bi-axial DMS for active control of surface nanotextures F-theta freeform surface (a)
(b)
nm 25
nm 77
1014
20 60
40
nm3
10 5
105
0
102
-5 -10
0
-20
X:
. 91
.19
110
123
25
Y:
Y:
X:
-15
-25
2
. 89 50
μm
30 1015 -60
1012
z / nm
z / nm
100
-10
(d)
nm3
(c)
0
50
50
100
x / m
150
200
250
60
90
120 150 180 210 Spatial frequency 1/mm
240
(b)
270
300
330
Window: Hann
9
106 103 100
0
10-3
-20 -30 0
10
nm
nm
10
X: Linear Y: Log 10
-40
-35
20
f=200/mm
10-1
-20
μm
μm
-30
Window: Hann
108
20 0
μm . 89
(a)
1011
15
-50 0
50
100
x / m
150
Characteristics of surface micro-topography
200
250
X: Linear Y: Log 10 30
60
90
120 150 180 210 Spatial frequency 1/mm
240
270
300
330
Power spectral density of cross-sectional profiles
19/50
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Part I: Diamond milling servo based machining system (b) Bi-axial DMS for active control of surface nanotextures
Characteristics of the tool loci for generating the hybrid structure
Characteristics of the sinusoid grid micro-structure with imposition of secondary unidirectional phase gratings
20/50
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Part I: Diamond milling servo based machining system (c) Intersecting DMS for generating hierarchical micro/nanostructures
v
Transfer motion of the spindle axis
PA
HCM
yS
Spindle feed motion in HCM
Rd
Tool loci
v oS
PB
v PC
ys
VCM
Spindle feed motion in VCM
os
oW
h/2 yW
xs
ym w/2
PD v
xW
Rd
xS
Side-feeding Tool loci Workpiece
The induced cutting modes in DMS
om
xm
Cutting kinematics for the multitier micronanostructure generation 21/50
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Part I: Diamond milling servo based machining system (c) Intersecting DMS for generating hierarchical micro/nanostructures Tool pose compensation
VCM HCM
Tool geometry compensation Optimal toolpath for a F-theta substrate
Conditions:
PDS: z(x,y)=ax2+by2+cy4 Feedrate: fx=fy=20μm/rev
Schematic of toolpath determination
Diamond tool: Rt=0.1 mm Inclination angle: α=0.5 degree. 22/50
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Part I: Diamond milling servo based machining system (c) Intersecting DMS for generating hierarchical micro/nanostructures
Conditions: PDS: z(x,y)=ax2+by2+cy4 Feedrate: fx=fy=20μm/rev Diamond tool: Rt=100μm
Features: Accurate PDS Homogeneous secondary nanostructures (nano- pyramids) Characteristics of the hybrid surface obtained by numerical simulation 23/50
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Part I: Diamond milling servo based machining system (c) Intersecting DMS for generating hierarchical micro/nanostructures
Cutting system:
Moore Nanotech 350FG Single crystal diamond tool with Rt=0.104mm Brass C2600 for the workpiece
Primary aspheric array Pitch=250 μm Apurture=200 μm Height=1 μm 24/50
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Part I: Diamond milling servo based machining system (c) Intersecting DMS for generating hierarchical micro/nanostructures Primary F-theta surface
(a)
Improved secondorder robust Gaussian regression filter
Nanostructured F-theta freeform surface
Nanopyramids 25/50
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Part I: Diamond milling servo based machining system (c) Intersecting DMS for generating hierarchical micro/nanostructures
Characteristics of the obtained secondary nano-pyramids 26/50
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Part I: Diamond milling servo based machining system (d) A combination of the intersecting and bi-axial DMS
0.115 0.11
(a) 0.105
zCLP / mm
-0.4
Toolpath
-0.2
-0.5
0.11
x
0.105 0.1 -0.3
fs
0 yCLP / mm 0.2
0.1 0.115 -0.3 -0.4
CLP
-0.6
-0.5
-0.6
(b)
-0.2 0 yCLP / mm 0.2
Side -feeding fg
-0.4
-0.8-0.4 0.4
-0.7
/ mm
xCLP / mm
zCLP / mm
zCLP / mm
State Key Laboratory in Ultra-precision Machining Technology
-0.7
-0.8 0.4
Tool loci in VCM Tool loci in HCM
0.11 0.105 0.1 -0.5
-1
0 yCLP / mm
-0.5 xCLP / mm 0.5 0
Characteristics of the micro-pyramid array with phase gratings on each side face 27/50
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Part I: Diamond milling servo based machining system A brief summary
Combining the concepts of fast- or slow-tool-servo (FTS/STS) and end-face raster milling, the mechanical machining system named Diamond Milling Servo (DMS) was proposed and investigated; The DMS based machining system is more suitable for large-scale generation of the microstructures due to the intrinsic constant cutting velocity; The DMS based machining system is promising for the generation of the hierarchical micro/nanostructures by actively controlling features of the residual tool marks.
28/50
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Part II: Rotary vibration assisted diamond milling servo Basic principle of the RV-DMS system (a)
Cutting kinematics th
ith
(i+1)
(i-1)th
Motion characteristics Spindle rotation (c-axis) and side-feeding along the x- and y-axis direction of the machine tool;
Forward feeding Side-feeding
S
x
o
Workpiece
y
Servo motion along the z-axis (from STS) for the generation of freeform primary surfaces; The rotary spatial vibrations for the assistance of the structure generation
Tool loci
(b)
Motion Features Workpiece S
Side-feeding
xt Diamond
Rd
tool
zt
x
xs
ot
zs S
os o
yt
ys
r
p
y
d pin
z
rv Se
xis le a
on oti m o
NX 30x,i P a sin R i x,i d n ( k ,l ) i 1 P x(Mk ,l ) r( k ,l ) N Y M 30y,i P P 0 y ( k ,l ) R z ( k ,l ) bi sin n ( k ,l ) y,i i 1 P P M f (r , ) ( k , l ) ( k , l ) z NZ ( k ,l ) 30z,i P Primary Surface ci sin ( k ,l ) z,i n i 1 Rotary Vibration
29/50
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Part II: Rotary vibration assisted diamond milling servo (a) Mechatronic design of the rotary vibration system Rotary vibration system
Design Criteria Compact and rotationally symmetric structure
Piezo-actuated three-DoF compliant vibrator
High working bandwidth
Four sets of L-FHs to achieve three-DoF motion guidance of the end-effector
Decoupled output motions of the end-effector High output stiffness for machining stability
Orthogonally arranged three piezoelectric actuators to achieve 3-DoF vibrations 30/50
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Part II: Rotary vibration assisted diamond milling servo (a) Mechatronic design of the rotary vibration system (b)
(a)
(c)
Elastic deformation behavior of the CSV with actuation along each direction FEA and analytical result comparisons FEA Analytical Deviation
C1,1out (μm/N)
out C2,2 (μm/N)
out C3,3 (μm/N)
0.118 0.107 9.32%
0.121 0.107 11.6%
0.047 0.034 27.66%
FEA Analytical Deviation
f1/Hz
f2/Hz
f3/Hz
2613.2 2664.1 1.95%
2625.9 2664.1 1.45%
4005.9 4340.8 8.36%
Equivalent stress
31/50
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Part II: Rotary vibration assisted diamond milling servo (a) Mechatronic design of the rotary vibration system
Configuration of the off-line testing system 32/50
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Part II: Rotary vibration assisted diamond milling servo (a) Mechatronic design of the rotary vibration system
0 -5 -10 0
1
2
3
4
Time / s
1
2
-0.1 3
4
3
4
10
-5 -10 0
-0.1 1
2
2
3
4
3
4
Time / s
5
(b)
0.2
0
-0.2 0
5
1
(b)
0.1
(a)
0
5
x z
x y
0.1
1.5%
0 -0.1 -0.2 0
5
Time / s
Time / s
12.254 μm
z
5
0.2
0
2
-4
Time / s
Displacement / m
Displacement / m
0.1
(a)
0
-8 0
5
y z
1
y 4
(b)
0.2
-0.2 0
10.100 μm
8
Displacement / m
(a)
Displacement / m
Displacement / m
x 5
Displacement / m
11.067 μm
10
1
2
3
4
5
Time / s
2 1.5 1
3 2
1000 y z
1 0 0
2000 3000 Frequency / Hz
4000
5000
(b)
f x, f y
Displacement / m
0.5 0
fz
f x, f y 1000
2000 3000 Frequency / Hz
4000
5000
y 3
(a)
fy fz
2 1 0 0
1000
2000 3000 Frequency / Hz
4000
5000
(b)
2 1.5
x z
f x, f y
fz
1 0.5 0 0
1000
2000 3000 Frequency / Hz
Displacement / m
fx
4
Displacement / m
(a)
fz
x
Displacement / m
3 2.5
Displacement / m
Displacement / m
Static performance tests
4000
5000
fM,x=f M,y=2.8 kHz Dynamic performance tests
6
(a)
fz
z 4 2 0 0 3 2
1000 y x
4000
5000
(b) fz
f x, f y
1 0 0
2000 3000 Frequency / Hz
1000
2000 3000 Frequency / Hz
4000
5000
f M,z=4.3 kHz 33/50
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Part II: Rotary vibration assisted diamond milling servo (b) RV-DMS for the generation of micro/nanostructures
(b) Workpiece S
Side-feeding
xt Diamond
Rd
tool
zt
x
xs
ot
zs S
os o
yt
ys
r
dle pin
s axi
z
rv Se
on oti m o
p
y
34/50
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Part II: Rotary vibration assisted diamond milling servo (b) RV-DMS for the generation of micro/nanostructures Numerical simulation
I
Primary surface
z( x, y ) Ax cos(2 f x x) Ay sin(2 f y y ) with Ax=Ay=1.25 μm, and fx=fy=5 mm-1
Machining parameters
n=7 rpm
f=15 μm/rev
Vibration parameters
II
Frequency: 200 Hz Amplitude: b=0.50 μm, c=0.25 μm (I) a=2.50 μm, b=0.50 μm (II) 35/50
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Part II: Rotary vibration assisted diamond milling servo (b) RV-DMS for the generation of micro/nanostructures
Detailed parameters employed in machining Diamond tool Radius Rt Rake face angle
Machine tool
104 μm 0o
Feedrate f Spindle speed Rotational distance Rd
Workpiece 15 μm/r 8 rpm 2.25 mm
Material
Brass C2600
Detailed parameters employed for the RV system f1=40 Hz * a1 / μm b1 / μm c1 / nm E1 E2 E3 E4 E5
0 0 0 1.5 0
0 0 0 0 0
0 0 75 0 0
f2=200 Hz a2 / μm b2 / μm c2 / nm 0 2.5 0 2 0
0.5 0.5 0.5 0.5 0.5
125 0 75 0 125
Primary surface Planar Planar Planar Planar Sinusoid grid **
36/50
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Part II: Rotary vibration assisted diamond milling servo (b) RV-DMS for the generation of micro/nanostructures Nano-dimple array generated in E1
Nano-ridge array generated in E2
37/50
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Part II: Rotary vibration assisted diamond milling servo (b) RV-DMS for the generation of micro/nanostructures
Hierarchical nano-dimple array generated in E3
Tadpole-looking nanostructures generated in E4
38/50
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Part II: Rotary vibration assisted diamond milling servo (b) RV-DMS for the generation of micro/nanostructures
Characteristics of the fabricated hierarchical micro/nanostructures 39/50
T
State Key Laboratory in Ultra-precision Machining Technology
超精密加工技術國家重點實驗室
Part II: Rotary vibration assisted diamond milling servo (c) RV-DMS for micro/nanomachining of brittle materials ST
xv S’ a sin(2 f vt x ) Rd ) yv k b sin(2z 'f vt y(k+1) p Cutting zv c sin(2 f vt z ) duration y y'
(a)
(b)
th
th
yv
s R
L
yt
xv
xt ot
d
t
o'
ST
hc,max v (t ) Maximum depth-of-cut: d
ov
C
Spindle
Diamond tool
ST
(b) z'
kth
(k+1)
yt
Cutting duration
y'
o'
Diamond tool
hc,max
to
d
M
tm vM
HSR
d
vC (t )
n Rd 30
arcsin 1 2 arcsin 0.5 2
Horizontal speed ratio:
te 0.5 pL
tm
DC (te to ) f v
th
pL
xv
hc,max ≅ c 2 v2n30 R 1 2 to
Duty cycle:
Tool Position
S’
te 0.5 pL
with: and:
n Rd
30 f v pL
a b
2
n Rd
30 f v a b , b nt Turning cos Milling a 2 b2 , 30 . 2
2
2
2
cd d 1 c c. 40/50
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超精密加工技術國家重點實驗室
Part II: Rotary vibration assisted diamond milling servo (c) RV-DMS for micro/nanomachining of brittle materials 3
(a)
Displacement / μm
2
z y x
1 0 -1 -2 -3 2
2.5
3
3.5 Time / s
1.5
4
4.5
5 -3
x 10
(b)
1
z / μm
0.5 0
fv=2 kHz
-0.5 -1 -1.5
2.4 μm
2 1
4.8 μm 0
-1 0 0.2 -0.2 x / μm
μm
-2
0.5
1. the spindle, 2. the fixture, 3 the slip ring, 4. the CSV, 5. the dynamometer, 6. the workpiece, 7. the tool holder and the diamond tool, 8. the piezo-actuators, and 9. the endeffector
Practical tool motion
y / μm
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超精密加工技術國家重點實驗室
Part II: Rotary vibration assisted diamond milling servo (c) RV-DMS for micro/nanomachining of brittle materials
Sa = 4.3 nm
Sa = 66.2 nm
Critical-depth-of-cut=58 nm Machined surface without vibration assistance
Critical-depth-of-cut=744 nm Machined surface with rotary vibration assistance
Characteristics of micro-topography of the micro-groove generated on single crystal silicon 42/50
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Part II: Rotary vibration assisted diamond milling servo A brief summary
Design, modeling, analysis and experimental tests of the piezo-actuated rotary compliant vibration mechatronic system are comprehensively conducted;
Theoretical and experimental investigation on the rotary vibration assisted diamond milling servo (RV-DMS) system for generating hierarchical micro/nano-structures as well as enhancing machinability of brittle materials are systematically conducted; The RV-DMS system is more promising for the generation of the hierarchical micro/nanostructures due to the inherent hierarchical cutting architecture and consistent cutting operation of the RV-DMS system.
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Overall contribution and future work Contribution Provide an efficient and powerful DMS based micro/nanomanufacturing system for large-scale generation of the micro-structured functional surfaces as well as the bio-inspired hierarchical micro/nanostructures; Provide the thorough and systematic guidance for advanced design and implementation of the compliant mechanism based mechatronic system with multiple degree-of-freedoms for micro/nanomanufacturing; Provide solid theoretical basis for optimal toolpath determination and structured surface estimation for the DMS based micro/nanomanufacturing system.
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超精密加工技術國家重點實驗室
Overall contribution and future work Future work
To improve the surface estimation model with consideration of system dynamics and cutting force variations. To develop self-sensing based feedback control strategy for nanopositioning of the diamond tool in the rotary vibration system. To synthesize motions of the rotary vibration system and the machine tool to have a coordinate operation for ultra-precision generation of the intricately shaped surfaces.
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超精密加工技術國家重點實驗室
Acknowledgements • Committee members for valuable guidance, discussions and insights. • My chief supervisor, Dr. Sandy To, for her continuous support and encouragements on my Ph.D. study and research. • Prof. Ehmann from Northwestern University for beneficial comments and guidance.
•All past and current members of the State Key Laboratory in Ultra-precision Machining Technology for their help on the experiments and enlightening discussions. •Specific acknowledgement is given to the research committee of the Hong Kong Polytechnic University for their generous support of this work with grant number of RTJZ.
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Publication Lists
1. Zhiwei Zhu, Suet To, and Shaojian Zhang, (2015). "Theoretical and experimental investigation on the novel end-fly-cutting-servo diamond machining of hierarchical micro--nanostructures" International Journal of Machine Tools and Manufacture, 94: 15-25. 2. Zhiwei Zhu, Suet To, and Shaojian Zhang, (2015) "Large-scale fabrication of micro-lens array by novel end-fly-cutting-servo diamond machining," Optics Express 23 (16), 20593-20604. 3. Zhiwei Zhu and Suet To, (2015) "Adaptive tool servo diamond turning for enhancing machining efficiency and surface quality of freeform optics", Optics Express, 23 (16), 20234-20248. 4. Zhiwei Zhu, Suet To, Xiaoqin Zhou, et al. (2016). "Characterization of spatial parasitic motions of compliant mechanisms induced by manufacturing errors", Journal of Mechanisms and Robotics- Transactions of the ASME, 8 (1), 011018. 5. Zhiwei Zhu, Suet To, and Shaojian Zhang, (2015). "Active control of residual tool marks for freeform optics functionalization by novel biaxial-servo assisted fly-cutting", Applied Optics, 54 (25), 7656-7662.
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超精密加工技術國家重點實驗室
Publication Lists
6. Suet To, Zhiwei Zhu*, and Peng Wang, (2015). Evolutionary diamond turning of optics for error correction covering a wide spatial spectrum. Optical Engineering, 54(1), 015103-015103. (*Corresponding author) 7. Zhiwei Zhu, Suet To, and Shaojian Zhang, (2015) "High throughput generation of hierarchical micro-/nanostructures by novel spatial vibration assisted diamond cutting." Advanced Materials Interfaces, doi: 10.1002/admi.201500477. 8. Zhiwei Zhu, Suet To, Gaobo Xiao, Kornel F. Ehmann, and Guoqing Zhang, (2015) "Rotary spatial vibration-assisted diamond cutting of brittle materials." Precision Engineering, doi: 10.1016/j.precisioneng.2015.12.007. 9. Zhiwei Zhu, Suet To, Kornel F. Ehmann, Gaobo Xiao and Wule Zhu, (2015) "A novel diamond micro-/nano-machining process for the generation of hierarchical micro-/nano-structures." Journal of Micromechanics and Microengineering, accepted.
10. Zhiwei Zhu, Suet To, Kornel F. Ehmann, Xiaoqin Zhou and Wule Zhu, " Design, analysis, and realization of a novel piezoelectrically actuated rotary spatial vibration system for micro-/nanomachining." IEEE/ASME Transactions on Mechatronics, under review.
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Conference attendance
1. Zhiwei Zhu and Suet To, "Nonlinear vibrations of a typical fast tool servo induced by the contacts between the piezo-actuator and the flexure mechanism", In: Proceedings of the 4th International Conference on Nanomanufacturing, 8-10 July, 2014, Bremen, Germany. 2. Zhiwei Zhu and Suet To, "Adaptive diamond turning for micro-structured surfaces." In: Asia Pacific Conference on Optics Manufacture 2014 (APCOM 2014), 9-11 November, 2014, Guangzhou, China. 3. Zhiwei Zhu and Suet To, "Spatial nano-vibrator assisted fly-cutting-servo diamond machining of micro-/nanostructured surfaces." In: CIRP 2015 SURFACES Scientific Technical Committee meeting, 22-28 August, 2015, Cape Town, South Africa.
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Q&A
Thanks for your attention!
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