Numerical Simulation and Experimental Study of Millisecond Percussion Drilling in Titanium Alloy

Area of Science:

• Materials Science
• Mechanical Engineering
• Aerospace Engineering

Background:

• Film-cooling holes are critical for turbine blade thermal management in aircraft engines.
• Drilling these holes in advanced materials like titanium alloy TC4 presents significant challenges.
• Optimizing laser drilling parameters is essential for achieving desired micro-hole characteristics.

Purpose of the Study:

• To investigate the effects of laser drilling parameters on the quality of film-cooling holes in TC4 titanium alloy.
• To determine the optimal laser drilling conditions for micro-hole fabrication.
• To provide insights into the relationship between process parameters and hole geometry.

Main Methods:

• Finite element analysis (FEA) using ANSYS software for laser drilling simulation.
• Experimental validation using an impact-drilling method on TC4 titanium alloy.
• Systematic variation of pulse width, pulse energy, and pulse count.

Main Results:

• Simulation results indicated pulse energy and count primarily influence hole diameters, while pulse count and width affect taper.
• Experimental data showed increased entrance/exit diameters with higher pulse energy (2.0-2.8 J).
• Taper increased with pulse width (0.6-1.4 ms) and pulse count (40-60), with both parameters also affecting roundness.

Conclusions:

• Laser drilling parameters critically influence the dimensional accuracy and roundness of film-cooling holes in TC4.
• Optimized parameter selection, guided by simulation and experimentation, is key for effective micro-hole drilling.
• This research provides a foundation for enhancing the manufacturing precision of turbine blade cooling features.