Statistical-experimental optimisation of laser drilling on Hastelloy X superalloy

The present study deals with the laser drilling process using the pulse method on the Hastelloy X superalloy. The effects of shielding gas pressure (GP), Peak power, duty cycle, and focal plane parameters on the hole geometry were studied using a full factorial experimental design. The results showed that increasing the Peak P and duty cycle increased the inlet and outlet hole diameter and Taper. Moreover, increasing the GP had an inverse relationship with the ID and Taper and a direct relationship with the OD. The focal plane was the most influential parameter in the responses. The Peak P and focal plan showed a direct and inverse relationship with the E response, respectively. A Taper and E close to zero are other successful results of this study. For a 250 mu m hole, the optimal parameters were calculated and proposed using a statistical model and validated with experimental results. The optimised parameters were a gas pressure of 8 bar, a Peak power of 1500 W, a duty cycle of 100 ms, and a focal plan of +1 mm. The optimal obtained responses were ID of 253.778 mu m, OD of 234.826 mu m, Taper of 0.5707 & ring;, and E of 0.0638.