Experimental study of fibre laser microdrilling of aerospace superalloy by trepanning technique

Abstract

In the present study, fibre laser microdrilling of NIMONIC®263 sheet is investigated through an experimental testing campaign. Design of experiments (DOE) and analysis of variance (ANOVA) are applied with the aim to study the influence of the process parameters on the hole geometry and metallurgical properties. The results show that the laser allows drilling ~0.4-mm-thick NIMONIC®263 sheets with a trepanning speed up to 600 mm/min, obtaining good tolerance, low recast layer and absence of microcracks

Experimental Investigation of Productivity, Specific Energy Consumption, and Hole Quality in Single-Pulse, Percussion, and Trepanning Drilling of IN 718 Superalloy

“…Some of the parameters were held constant during the entire experimentation and are presented in Table 2. In this study, the input variables were chosen because of their significant impact on hole quality, material removal rate, and specific energy consumption [29][30][31][32][33][34][35][36]. The ranges of input parameters were selected after the trial experimentation so that drilling of holes gives better hole quality and material removal rate with minimum energy consumption.…”

Performance Evaluation and Comparison between Direct and Chemical-Assisted Picosecond Laser Micro-Trepanning of Single Crystalline Silicon

“…The importance of micro through-holes can be represented by many applications, from solar cell and micro-devices to injection nozzles and turbine blades [1,2,3,4,5]. Taking the solar cell as an example, to avoid the shading effect of front electrodes, dense via holes that have a higher aspect ratio and small diameter are fabricated in solar panels to realize emitter wrap-through (EWT) or metal wrap-through (MWT) design, so that conventional top contact with front electrodes can be shifted to the rear through via holes, which increases the energy conversion efficiency [5].…”

“…Taking the solar cell as an example, to avoid the shading effect of front electrodes, dense via holes that have a higher aspect ratio and small diameter are fabricated in solar panels to realize emitter wrap-through (EWT) or metal wrap-through (MWT) design, so that conventional top contact with front electrodes can be shifted to the rear through via holes, which increases the energy conversion efficiency [5]. For turbine blades working under a high-temperature flame, small holes are usually drilled to form an effusion cooling system, so that the thermal stress that is applied on the blade surface can be reduced, and premature failure can be avoided [3].…”

“…In terms of micro-drilling application, laser has shown good performance, and several drilling techniques have been proposed according to the relative movement between the laser beam and the workpiece, such as percussion drilling [2], trepanning [8], and laser helical drilling [9]. Among these drilling schemes, laser trepanning appears to be more competitive due to its flexibility with laser scanning path control, enabling it to make free-form holes with different contours at the hole entrance/exit [3,8]. Therefore, the laser trepanning scheme has been widely employed for micro-hole production in various materials, such as superalloy [3,8], titanium alloy [10], tungsten carbide [4], polymers [11], and ceramics [12].…”

“…Among these drilling schemes, laser trepanning appears to be more competitive due to its flexibility with laser scanning path control, enabling it to make free-form holes with different contours at the hole entrance/exit [3,8]. Therefore, the laser trepanning scheme has been widely employed for micro-hole production in various materials, such as superalloy [3,8], titanium alloy [10], tungsten carbide [4], polymers [11], and ceramics [12].…”