3 Study on Improving the Performance of Nitinol Cardiovascular Stent …
33
(a) Nitinol tube
(b) Stent after laser cutting
Fig. 3.1 Stents
Fig. 3.2 The composition and content of nitinol tube
Fig. 3.1a, and its composition and content are shown in Fig. 3.2. The cardiovascular
stent (hereinafter referred to as stent) after fiber laser cutting is shown in Fig. 3.1b,
and it is used as the raw materials for electropolishing.
3.2.2 Equipment and Methods
The wet laser cutting system in this experiment is shown in Fig. 3.3a, which is mainly
composed of computer controller, Theta TLS-HT1100 fiber laser, focusing lens and
motor with clamping device. The laser parameters in the experiment are shown in
Table 3.1. The pulse width was 14 µs, the laser power was 135 w, the pulse frequency
was 9500 Hz, and cutting speed was 5 mm/s. The auxiliary gas in laser cutting was
argon, and its pressure was 0.7 MPa. The water source and the tail end of nitinol
tube were connected by soft water pipe, and the water pressure was 0.06 MPa. The
electropolishing system is shown in Fig. 3.3b, which is mainly composed of DC
power supply, electromagnetic stirrer, electropolishing cell, temperature sensor and
fixture. The electropolishing experiment was carried out at room temperature (28
33
(a) Nitinol tube
(b) Stent after laser cutting
Fig. 3.1 Stents
Fig. 3.2 The composition and content of nitinol tube
Fig. 3.1a, and its composition and content are shown in Fig. 3.2. The cardiovascular
stent (hereinafter referred to as stent) after fiber laser cutting is shown in Fig. 3.1b,
and it is used as the raw materials for electropolishing.
3.2.2 Equipment and Methods
The wet laser cutting system in this experiment is shown in Fig. 3.3a, which is mainly
composed of computer controller, Theta TLS-HT1100 fiber laser, focusing lens and
motor with clamping device. The laser parameters in the experiment are shown in
Table 3.1. The pulse width was 14 µs, the laser power was 135 w, the pulse frequency
was 9500 Hz, and cutting speed was 5 mm/s. The auxiliary gas in laser cutting was
argon, and its pressure was 0.7 MPa. The water source and the tail end of nitinol
tube were connected by soft water pipe, and the water pressure was 0.06 MPa. The
electropolishing system is shown in Fig. 3.3b, which is mainly composed of DC
power supply, electromagnetic stirrer, electropolishing cell, temperature sensor and
fixture. The electropolishing experiment was carried out at room temperature (28