Experiments of drilling micro-holes on superalloy with thermal barrier coatings by using femtosecond laser

Abstract

A femtosecond laser was used to process micro-holes on the nickel-based superalloy with thermal barrier coatings. Scanning electron microscope (SEM) was used to observe the morphology of micro-holes inlet, outlet and the side wall. The changes of morphology with laser focusing position and laser power were analyzed. The results showed that the micro-holes processed by femtosecond laser required a certain amount of focus position to optimize the processing quality. The entrance was not round sometimes and the micro-holes outlet was irregular with high power laser machining. A further repair of micro-hole by using low power femtosecond laser was presented. Low laser power modification can improve the quality of micro-holes.

Keywords:

• Femtosecond laser
• focus position
• laser power
• low laser power modification

Additional information

Funding

This work was supported by grants from the National Natural Science Foundation of China (51705401), the Natural Science Foundation of Jiangsu Province of China (SBK2017041423) and the Fundamental Research Funds for the Central Universities (300102259505).