Research on burr height prediction and inhibition strategy of high-temperature alloy ultrasonic vibration micro drilling outlet

GH4169 is a nickel-based super-alloy characterized by outstanding resistance to high temperatures, corrosion, and fatigue. Owing to these properties, it is extensively used in the aerospace industry for manufacturing hot-section components, particularly turbine blades in aero-engines. Air film holes are critical structural features on aircraft engine turbine blades, burr formation is a common occurrence in the drilling process. This article analyzes the process of burr formation in conventional drilling(CD) and ultrasonic assistant vibration drilling(UAD), develops an analytical model for predicting burr height evolution in UAD based on the principle of energy conservation. The framework integrates dynamic cutting mechanics with plastic deformation energy dissipation, establishing quantitative correlations between processing parameters and burr height. Experimental results demonstrate that, running at 9000 rpm spindle rotation speed, while maintaining a 5 mm/min feeding motion, UAD with a 6µm amplitude reduces the axial force from 13.29 N in CD to 7.34 N, representing a 44.75% decrease. Additionally, the burr height decreases from 36.13µm to 28µm, representing a 22.5% reduction. The burr morphology also changes, forming a ring of thin, curved burrs at the hole exit. To quantify the impact of machining conditions on burr dimensions, multivariate regression analysis(MRA) was systematically implemented in the study, while also calculating the material removal rate (MRR). Through optimization, the study identified a set of ultrasonic micro-drilling parameters. The parameter configuration, ultrasonic amplitude: 6µm; feed rate: 6.3 mm/min; spindle speed: 9000 r/min, achieves optimal burr suppression, while sustaining a high material removal rate.