激光微加工对Ti6Al4V表面形貌及润湿性影响的研究

为了在Ti6Al4V表面加工不同的微结构，改变其润湿性，使其表面具有超疏水性，采用纳秒光纤脉冲激光对Ti6Al4V表面进行了微加工，研究了脉冲能量密度和扫描间距对点阵、线阵及网格3种微结构的表面形貌及润湿性的影响，建立了接触角与表面特征参量S_a, S_d的关系。结果表明, 脉冲能量和扫描间距对点阵、线阵及网格结构的表面形貌参量S_a, S_d均有所影响，且对网格结构的S_a和S_d的影响程度最大，线阵结构次之，点阵结构最小；激光加工Ti6Al4V后，其表面皆会发生从超亲水到疏水甚至超疏水的自发转变，不同的脉冲能量、扫描间距加工的微结构均对表面润湿性有不同程度的改善，其中网格结构对表面湿润性的改善最好，线阵次之，点阵最差；网格、线阵、点阵结构的最大及最小接触角分别为165°, 160.5°, 142.4°；132.9°, 97°, 94.6°，具有最大接触角的表面参量S_a, S_d分别为0.97μm, 1.38；1.62μm, 1.04；4.14μm, 2.39。该研究对改善Ti6Al4V表面润湿性具有一定参考意义。

The effects of laser micromachining on surface morphology and wettability of Ti6Al4V

In order to process different microstructures on the Ti6Al4V surface and change its wettability to make the surface superhydrophobic, the nanosecond fiber pulsed laser was used to micro-fabricate the Ti6Al4V surface. The effects of the pulse energy density and the scanning interval on the lattice surface morphology and wettability of 3-D microarrays, linear arrays, and surface microstructures were investigated. The results show that the pulse energy and scanning interval affected the surface morphology parameters S_a, S_d, among which, the S_a and S_d of the rid structure were affected the most, followed by the linear array structure, while the lattice structure affected the smallest. After Ti6Al4V was processed by laser, spontaneous transition from superhydrophilic to hydrophobic or even superhydrophobic will occur on the surface. Microstructures processed with different pulse energies and scanning intervals had different degrees of surface wettability improvement, among which the grid structure had the best improvement on the surface wettability, followed by the linear array, and the worst was the lattice; The maximum and minimum contact angles of the grid, linear array, and lattice structure are 165 °, 160.5 °, 142.4 °; 132.9 °, 97 °, 94.6 °, and the surface parameters S_a and S_d with the maximum contact angle are 0.97μm, 1.38; 1.62μm, 1.04; 4.14μm, 2.39, respectively. This research has certain reference significance for improving the surface wettability of Ti6Al4V.