第五章 結論與展望
5.2 展望
根據數值模擬具殘留應力 20 MPa 之鋁板,工作頻率與板厚乘積 於 0 到 10 MHz‧mm 範圍內,高模態A 藍姆波之相速度偏移量最大2
內之殘留應力。未來可應用藍姆波量測大型鋼材於製造過程中所產生 的殘留應力。
利用高模態藍姆波量測平板聲彈效應可得到較佳的效果,但在實 驗的過程中,量測高模態的藍姆波並不容易。高模態的藍姆波容易受 到外界雜訊的干擾,克服雜訊是相當重要的的課題,未來可加入帶通 濾波器(band-pass filter),以期得到所要量測的頻率範圍。
本研究曾採用 CFPI 作為量測藍姆波擾動的儀器,獲致不錯的結 果,但校準光束進入 CFPI 共振腔耗時過長,未來可利用光纖將雷射 光光源導入於共振腔內,縮短校準光路的時間,亦可減少光強度的衰 減。
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附 錄
3. 矩陣Q 的分量為 ±
* *
1k 55 3 1k 1 55 3k
q+ =ic ς p+ +ik c p+
* *
2k 44 3 2k 2 44 3k
q+ =ic ς p+ +ik c p+
* * *
3k 1 31 1k 2 32 2k 33 3 3k
q+ =ik c p+ +ik c p+ +ic ς p+
* *
1k 1k 55 3 1k 1 55 3k
q− =q+ = −ic ς p− +ik c p−
* *
2k 2k 44 3 2k 2 44 3k
q− =q+ = −ic ς p− +ik c p−
* * *
3k 3k 1 31 1k 2 32 2k 33 3 3k
q− = −q+ =ik c p− +ik c p− −ic ς p−
表 1 矽的二階與三階彈性常數
密度(kg m3) 彈性常數(GPa)
ρ c 11 c 12 c 44
2329 165 64 79.2
c111 c112 c123 c144 c155 c456
-825 -451 -64 12 -310 -64
表 2 鍺的二階與三階彈性常數
密度(kg m3) 彈性常數(GPa)
ρ c11 c12 c44
5323.4 129 48 67.1
c111 c112 c123 c144 c155 c456 -720 -380 -30 -10 -305 -45
表 3 鋁的二階與三階彈性常數
密度(kg m3) 彈性常數(GPa)
ρ c11 c12 c44
2696 109.26 56.55 26.36
c111 c112 c123 c144 c155 c456
-107.6 -31.5 3.6 -2.3 -34 -3
表 4 銅的二階與三階彈性常數
密度(kg m3) 彈性常數(GPa)
ρ c11 c12 c44
5322 128.9 48.3 67.1
c111 c112 c123 c144 c155 c456
-710 -389 -18 -23 -29.2 -53
表 5 拉伸試驗應變值
Displacement (μm) Strain (με)
5 10 10 22 15 33 20 45 25 58 30 72 35 84 40 98 45 113 50 125 55 139 60 155 65 171 70 185 75 202 80 215 85 233 90 249 95 265 100 284
圖 1.1 晶格不相配造成薄膜產生拉應力
圖 1.2 晶格不相配造成薄膜產生壓應力 substrate
film
substrate film
substrate film
substrate film
ν N n
ξ x
X
ui
uf
u
圖 2.1 受預應變質點在自然狀態、初始狀態及最後狀態的座標系統
z1
z2
1 2
X1
X2
X3
Ge Si
θ
圖 2.2 單晶矽鍺薄膜結構及參考座標(與材料主軸重合)
0 4 8 12 16 20 Frequency (MHz)
0 4 8 12 16 20
Phase velocity (mm/μs)
A0 S0
A1 S1 S2 A2
圖 3.1 Ge(500nm)/Si 頻散曲線圖,實線代表薄膜未受應力,
虛線代表薄膜受 5GPa 壓應力
0 4 8 12 16 20
Frequency (MHz) 0
4 8 12 16 20
Phace velocity (mm/μs)
A0 S0
A1 S1 S2 A2
0 4 8 12 16 20 Frequency (MHz)
0 4 8 12 16 20
Phace velocity (mm/μs)
A0 S0
A1 S1 S2 A2
圖 3.3 Ge(5000nm)/Si 頻散曲線圖,實線代表薄膜未受應力,
虛線代表薄膜受 5 GPa 壓應力
0 4 8 12 16 20
Frequency (MHz) 0
1 2 3 4 5
Phace velocity (mm/μs)
A0
圖 3.4 Ge(5000nm)/Si 之A0模態頻散曲線圖
0 4 8 12 16 20 Frequency (MHz)
-120 -80 -40 0
Phase velocity shift (m/s)
Thickness of Ge 500 nm 1000 nm 5000 nm
圖 3.5 Ge/Si 結構A0模態相速度偏移量
4 8 12 16 20
Frequency (MHz) -160
-120 -80 -40 0
Phase velocity shift (m/s)
Thickness of Ge 500 nm 1000 nm 5000 nm
圖 3.6 Ge/Si 結構A 模態相速度偏移量 1
15 16 17 18 19 20 Frequency (MHz)
-160 -120 -80 -40 0
Phase velocity shift (m/s)
Thickness of Ge 500 nm 1000 nm 5000 nm
圖 3.7 Ge/Si 結構A 模態相速度偏移量 2
0 4 8 12 16 20
Frequency (MHz) -40
-30 -20 -10 0
Phase velocity shift (m/s)
Thickness of Ge 500 nm 1000 nm 5000 nm
圖 3.8 Ge/Si 結構S 模態相速度偏移量 0
8 12 16 20 Frequency (MHz)
-160 -120 -80 -40 0
Phase velocity shift (m/s)
Thickness of Ge 500 nm 1000 nm 5000 nm
圖 3.9 Ge/Si 結構S 模態相速度偏移量 1
12 14 16 18 20
Frequency (MHz) -120
-80 -40 0
Phase velocity shift (m/s)
Thickness of Ge 500 nm 1000 nm 5000 nm
圖 3.10 Ge/Si 結構S 模態相速度偏移量 2
0 2 4 6 8 10 Frequency<thickness (MHz•mm) 0
2 4 6 8 10
Phase velocity (mm/μs)
圖 3.11 鋁板之頻散曲線圖,黑線代表未受應力,紅線代表鋁板受應 力 20 MPa
5 5.5 6 6.5 7
Frequency<thickness (MHz•mm) 2.89
2.895 2.9 2.905 2.91 2.915
Phase velocity (mm/μs)
圖 3.12 鋁板之A 模態頻散曲線局部圖0
0 2 4 6 8 10
4 6 8 10
9 9.2 9.4 9.6 9.8 10
2 4 6 8 10
6 7 8 9 10
0 2 4 6 8 10 Frequency<thickness (MHz•mm) 0
2 4 6 8 10
Phase velocity (mm/μs)
圖 3.23 鋁板之頻散曲線圖,黑線代表鋁板未受應力,紅線代表鋁板 受應力 1 GPa
0 4 8 12 16 20
Axial Stress σ11 (MPa) 0
4 8 12
Phase velocity shift |ΔC | (m/s) Mode
A0 A1 A2 A3 A4
圖 3.24 1mm 厚鋁板反對稱模態平均相速度偏移量
0 4 8 12 16 20 Axial Stress σ11 (MPa)
0 10 20 30
Phase velocity shift |ΔC | (m/s) Mode S
0
S1 S2 S3 S4
圖 3.25 1mm 厚鋁板之反對稱模態平均相速度偏移量
圖 4.1 刀鋒技術示意圖
圖 4.2 微型拉伸試驗機(圖右)與類比電壓放大器 (圖左) to detector He-Ne laser
Surface wave
Lens
Knife edge
Focussed incident beam
0 20 40 60 80 100 Displacement (μm)
0 100 200 300
Strain (μ)
圖 4.3 壓電推桿位移與試片軸向應變曲線
mirror Nd:YAG Laser
He Ne laser
AD card
PD
Signal
Q-switch
DC power supply
pinhole Motorized Translation
Stages
NI-7344
Tensile testing machine lens
lens cylindrical
lens mirror
0 2 4 6 8 10
圖 4.7 頻域訊號之觀窗函數
圖 4.9 經觀窗函數處理後之藍姆波相速度灰階圖
0 2 4 6 8 10
Time (μs) 5
8 11
Distance (mm)
圖 4.10 刀鋒技術量測鋁板的雷射生成藍姆波訊號
0 2 4 6 8 10
Frequency (MHz) 0
2 4 6 8 10 12
Wave number (rad/mm)
0 0.05 0.1 0.15 0.2
圖 4.11 刀鋒技術量測鋁板之雷射生成藍姆波線掃瞄灰階圖
0 2 4 6 8 10 Time (μs)
10 16
13
Distance (mm)
圖 4.13 壓電推桿行程 0 mμ 之鋁板藍姆波訊號圖
圖 4.14 壓電推桿行程為 0 mμ 之鋁板的雷射生成藍姆波線掃瞄灰階 圖
0 2 4 6 8 10
Time (microsec) 0
10 20 30
Distance
-0.55 -0.35 -0.15 0.05 0.25
圖 4.15 壓電推桿行程為 0 mμ 之鋁板藍姆波相速度灰階圖,實線為無 預應力負載之理論頻散曲線
0 2 4 6 8 10
Time (μs) 10
16
13
Distance (mm)
圖 4.16 壓電推桿行程50 mμ 之鋁板雷射生成藍姆波訊號
0 2 4 6 8 10
Frequency (MHz) 0
2 4 6 8 10 12
Wave number (rad/mm)
A0
S0
A1
0 2 4 6 8 10 Time (μs)
10 16
13
Distance (mm)
圖 4.19 壓電推桿行程100 mμ 之鋁板的雷射生成藍姆波訊號
圖 4.20 壓電推桿行程為100 mμ 之鋁板的雷射生成藍姆波線掃瞄灰階 圖
0 2 4 6 8 10
Time (microsec) 0
10 20 30
Distance
-0.6 -0.3 0 0.3 0.6
圖 4.21 壓電推桿行程為100 mμ 之鋁板藍姆波相速度灰階圖,實線為 無預應力負載之理論頻散曲線
0 2 4 6 8 10
Time (μs)
-0.8 -0.4 0 0.4 0.8
10 mm 13 mm
16 mm
Distance
圖 4.22 壓電推桿行程為 0 mμ 之銅箔的雷射生成藍姆波訊號
0 2 4 6 8 10
Frequency (MHz) 0
2 4 6 8 10 12
Wave number (rad/mm) A0
S0
A1
圖 4.25 壓電推桿行程50 mμ 之銅箔的藍姆波相速度灰階圖,實線為
圖 4.27 壓電推桿行程100 mμ 之銅箔的藍姆波相速度灰階圖,實線為 無預應力負載之理論頻散曲線
0 2 4 6 8 10
Frequency (MHz) 0
2 4 6 8 10 12
Wave number (rad/mm)
0 0.03 0.06 0.09 0.12 0.15 0.18 0.21 0.24
A0
S0
mirror
0 2 4 6 8 10 Time (μs)
10 16
13
Distance (mm)
圖 4.29 CFPI 量測鋁板之雷射生成藍姆波訊號
圖 4.30 CFPI 量測鋁板之雷射生成藍姆波線掃瞄灰階圖
0 2 4 6 8 10
Time (microsec) 0
10 20 30
Distance
-1.4 -0.9 -0.4 0.1 0.6
圖 4.31 CFPI 量測鋁板之藍姆波相速度灰階圖,實線為理論頻散曲線
0 2 4 6 8 10
Frequency (MHz) 0
2 4 6 8 10 12
Wave number (rad/mm)
A0 S0 A1
S1