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

## TL;DR

This paper studies how to efficiently drill tiny holes in titanium alloy turbine blades using laser techniques, focusing on optimizing parameters like pulse energy and width.

## Contribution

The study introduces a combined simulation and experimental approach to optimize laser drilling parameters for micro-hole formation in titanium alloy.

## Key findings

- Pulse energy and pulse count mainly affect entrance and exit diameters of micro-holes.
- Taper increases with wider pulse widths and higher pulse counts.
- Roundness of holes is significantly influenced by pulse width and pulse count.

## Abstract

This study addresses the challenge of drilling film-cooling holes in the turbine blades of aircraft engines. Titanium alloy TC4 was selected as the experimental material. The laser-drilling process was simulated with ANSYS to determine optimal parameters, which were subsequently applied in machining trials. An impact-drilling method was then used to evaluate how pulse width, pulse energy, and pulse count affect micro-hole entrance and exit diameters, taper, and roundness. Simulations revealed that pulse energy and pulse count predominantly govern entrance and exit diameters, whereas pulse count and pulse width exert a stronger influence on taper. Experiments confirmed that entrance and exit diameters increased as pulse energy rose from 2.0 J to 2.8 J; taper increased as pulse width widened from 0.6 ms to 1.4 ms; and entrance diameter, exit diameter, and taper all grew as pulse count rose from 40 to 60. Pulse width and pulse count also significantly affected hole roundness.