Biomedical Engineering Reference
In-Depth Information
80
70
60
50
40
30
N-implanted
C-implanted
O-implanted
Control
20
10
0
0
50
100
150
200
Depth (nm)
FIGURE 19.26
Ni depth profi les acquired from the three PIII samples and control.
24
160
NiTi control
40 kV N-implanted 450
°
C-annealed
160
24
22
22
140
140
Young's modulus
Nanohardness
20
20
Young's modulus
Nanohardness
18
120
120
18
16
16
100
100
14
14
12
80
80
12
10
10
60
60
8
8
40
6
40
6
4
4
20
20
2
2
0
0
0
0
0
20
40
60 80 100 120 140 160 180
Depth (nm)
0
20
40
60
80
100 120 140 160
Depth (nm)
40 kV C-implanted 600
°
C-annealed
24
160
40 kV C-implanted 600
°
C-annealed
160
24
150
22
22
140
140
20
Young's modulus
Nanohardness
Young's modulus
Nanohardness
20
130
18
120
120
18
110
16
16
100
100
14
14
8
90
12
80
12
70
10
10
60
60
8
8
50
40
6
40
6
30
4
4
20
20
2
2
10
0
0
0
0
0
20
40
60 80 100 120 140 160
Depth (nm)
0
20
40
60
80
100 120 140 160
Depth (nm)
FIGURE 19.27
Hardness and modulus profi les of NiTi alloy before and after N, C, and O-PIII treatments.
(From Yeung, K.W.K. et al.,
J. Biomed. Mater. Res.
,
75A, 256, 2005. With permission.)
sample, the maximum hardness is 11 GPa at 40 nm from the surface. It gradually decreases to
5 GPa at 165 nm. The Young's modulus, being about 150 GPa at the topmost surface, decreases to
70 GPa gradually with depth. In the acetylene-implanted sample, the maximum hardness is 9.5 GPa
at around 30 nm from the surface and gradually diminishes to 4.5 GPa at 150 nm. The Young's
modulus exhibits the maximum value of 110 GPa at the topmost layer and then decreases gradually
