利用皮秒激光器在镍铝青铜合金表面制备了具有不同微观形貌的微纳米复合结构,再通过硬脂酸进行表面修饰。采用扫描电镜和X射线衍射仪等表征了所得表面的形貌和化学成分。研究结果表明,经皮秒激光加工和硬脂酸修饰后,表面的接触角都达到150°以上。不同的脉冲能量密度下,试样表面的微观形貌和润湿性不同。随着脉冲能量密度的增大,修饰后的试样表面的滚动角逐渐减小,当脉冲能量密度为6.85 J/cm ²时,滚动角减小到7°,随着脉冲能量密度的进一步增加,滚动角又逐渐增大。耐蚀性测试结果表明:超疏水镍铝青铜合金表面具有更好的耐腐蚀性能。采用优化的工艺参数可以在镍铝青铜合金上加工出超疏水表面,有助于提高其耐腐蚀性能。

采用射频磁控溅射技术在Si(111)衬底上制备了多组分ZnO 基陶瓷薄膜，利用Nd∶YAG 激光器对多组分ZnO基陶瓷薄膜进行了激光冲击处理，研究了激光冲击处理对多组分ZnO 基陶瓷薄膜压敏电性能的影响。结果表明，激光冲击处理后，薄膜的晶粒尺寸显著减小，表面更加平整致密。薄膜的压敏电性能得到了不同程度的改善，其中非线性系数的提高幅度最大为65.2%，压敏电压降低幅度最大为38.92%，漏电流密度降低幅度最大为30.51%。薄膜中晶粒细化，晶格畸变加强，晶界处的界面态密度激增，导致薄膜非线性系数激增，从而有效改善了多组分ZnO基陶瓷薄膜的压敏电性能。

研究了飞秒激光辐照对GaAs/Ge 太阳能电池的损伤效应，利用光学显微镜和非接触光学轮廓仪表征电池表面损伤形貌，并用伏安特性测试系统表征电池辐照前后的光伏特性。分析了不同激光能量密度下，激光烧蚀对电池表面形貌及电学性能产生的损伤程度。实验结果表明，激光能量密度小于0.53 J/cm2时，仅损伤到减反射膜；随激光能量密度的增加，电池损伤深度不断增加，当能量密度为0.78 J/cm2 时，已损伤到电池发射区；电池性能参数如短路电流、开路电压、最大功率和填充因子随激光能量密度的增加而衰减，衰减幅度先增加后减小；在所有测试参数中，光电转化率的退化最为明显。飞秒激光辐照对太阳能电池具有破坏性的影响，这直接影响到电池的光伏特性。

We study nanometer copper thin films prepared by magnetron sputtering and treated with laser shock processing (LSP). We observe the formation of firstborn twin crystals and some complete twin crystals in the copper thin films. After LSP, scanning electron microscope (SEM) images show obvious plastic deformation of the copper grain on the film surface, dramatically increased grain size, and the appearance of a large number of twin crystals. Moreover, the width of the crystals is a few dozen nanometers, and the cross angle is more than or close to 90o. Many vacancy defects appear during the sliding of atomic plane, which leads to a faulty structure; however, no obvious dislocation is observed. These substructures play a significant role in improving the mechanical performance of nanometer copper thin films.

应用激光冲击强化处理技术, 对不同状态下Fe40NiCrSiAl合金材料进行了强化处理, 并对其硬度、弹性模量、摩擦系数和磨损特征进行了测试和分析。实验结果表明, 激光冲击处理轧制态Fe40NiCrSiAl合金, 其硬度提高了25.22%, 弹性模量提高了7.17%, 摩擦系数降低了13%, 以剥落磨损为主; 激光冲击处理轧制态Fe40NiCrSiAl合金后再进行退火处理, 其硬度下降了7.59%, 弹性模量下降了6.25%, 摩擦系数降低了13%, 以磨粒磨损为主; 轧制态材料经纯退火处理后, 硬度降低了21.65%, 弹性模量下降了28.58%, 摩擦系数基本不变, 以磨粒磨损为主。

研究基于激光冲击诱导残余应力产生原理，把激光冲击诱导的最终稳定的残余应力看成激光冲击引起的残余应力与为满足平衡而产生的残余应力的代数和，提出了残余应力预测方法。通过激光冲击平板件的残余应力预测发现，模拟结果与实验结果十分接近。说明此方法可实现对工件全尺寸的残余应力预测，为后续的分析提供了条件。另外，对激光冲击处理圆角试样产生的残余应力进行了模拟研究，发现工件的形状对最终稳定的残余应力的分布存在影响，表现为表面应力值和残余压应力的深度发生了变化。说明此方法可能实现激光冲击处理任意形状工件的残余应力预测。

数值模拟是预测激光冲击残余应力场、研究激光冲击参数对残余应力场影响的一种有效方法。采用显式动力有限元软件ANSYS/LS-DYNA对激光冲击处理(LSP)40Cr钢残余应力场进行三维数值模拟; 建立了激光冲击处理40Cr钢残余应力场有限元分析(FEA)模型,实现了激光冲击处理40Cr钢残余应力场的数值模拟; 模拟研究了激光功率密度、激光脉冲持续时间、激光光斑尺寸对40Cr钢残余应力场的影响。数值模拟结果表明,残余应力模拟值与实测值之间有着较好的一致性; 在激光脉冲持续时间一定的条件下,要想获得最大的表面残余压应力,存在一个最佳的激光功率密度; 在激光功率密度一定并且脉宽大于45 ns的情况下,表面残余压应力随激光脉冲持续时间的增加而减小; 在激光功率密度、激光脉冲持续时间一定的条件下,表面残余压应力随光斑直径增大而增大。

Firstly, 45# steel was quenched by the NEL-2500A rapidly axial flow CO2 laser. The experimental parameters were the laser power of 750 W, the laser beam diameter of 4 mm, the scanning velocity of 7 mm/s. The thickness of coating layer was 0.1 mm and the width was 8 mm. Secondly, the martensite induced by laser quench was shocked by Nd:YAG laser. The parameters of laser shock processing were the wavelength of 1.06 μm, the pulse duration of 23 ns, and theoutput energy of 16-20 J. The laser was focused on a spot of φ7 mm. K9 optical glass was used as confinement. The sample was coated with black paint 86-1 (the thickness is about 0.025 mm). By testing and analysis of samples which were treated by laser quench and laser quench+shock with transmission electron microscope (TEM), it was discovered that the surface layer of martensite was deformed plastically by laser shock processing. In the secondary hardened zones, there were a lot of slender secondary twin crystal martensites, dislocation tangles, and cellular dislocations. Compared with that of the hardened zones through laser quench only, the residual stress and mechanical properties of the secondary hardened zones were improved and increased through laser compound method.