Study of Femtosecond Laser Micro-nano-structural Surface Inducing on 316L Stainless Steel

• Main Authors: Ching-IChu, 朱靜宜
• Other Authors: Long-Sun Chao
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/n52et5

碩士 === 國立成功大學 === 工程科學系碩士在職專班 === 106 === In the research, it is expected to make microstructures on 316L stainless steel surface by the surface treatment technology of femtosecond laser. The goal is that the resulting hydrophilic structure can reaches the serum contact angle smaller than 20 degrees. The produced structure could help to solve the shortcomings of the commercially available stents. In the work, the Taguchi method is utilized to design the experimental study with the L18 orthogonal table. Eight control factors are chosen, including laser repetition frequency (MHz), laser power (W), overlapping (mm), scan speed (mm/sec), focus height (mm), scan path, nitrogen flow rate (L/min) and suction flow rate (L/min). The quality characteristic is the contact angle and the smaller-the-better (STB) is selected. From the experimental data, it can be understood that the influences of the control factors on the contact angle. The optimal combination of the control factors is that the nitrogen flow rate is 20 L/min, the laser power is 1.2 W, the laser repetition frequency is 1 MHz, the overlapping is 0.009 mm, the scanning path is linear scan, the scanning speed is 1200 mm/sec. The resulting contact angle can reach 13.03 degrees. It is expected that the study results can be used as a reference for the future design of hydrophilic structure.