激光冲击强化K403镍基高温合金表面纳米化（英文）

Nanocrystallization of Ni-based superalloy K403 by laser shock peening

针对K403镍基高温合金铸造构建易发生裂纹、腐蚀、磨损的问题,采用激光冲击强化技术对K403薄片试件进行处理,使试件表面纳米化提高材料力学性能。利用X射线衍射、SEM扫描电镜、TEM透射电镜分析了材料表面纳米晶层的形成机理。实验结果表明:激光诱导的高压等离子体冲击波可以在样品表面上形成226 nm厚的纳米晶层;从SEM和TEM结果可以看出,激光冲击强化不会改变材料表面物相。在高冲击波压力下,K403试样表面组织产生了位错和纳米级晶粒细化。

The surface of the K403＇s thin slice specimen uses laser shock processing technology in order to strengthen the surface on the nanocrystallization, located on the surface of the specimen, for the cast parts of the nickel-based superalloy K403, which produced cracks, corrosion, and wear. The formation mechanism of the nano-crystal layer on the surface was analyzed by these technologies using X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and transmission electron microscopy （TEM）. The results showed that a nanocrystalline layer of 226 nanometers thick could be prepared by laser- induced high-pressure plasma shock wave on the specimen＇s surface. The results of XRD and SEM showed that it will not change the phase structure by that laser shock processing the refined surface grain structure. Under the high pressure, the surface microstructure of K403 specimen generated a great number of dislocations and refinement grains into nanoscaie.