Comparative study of ultrasonic vibration and conventional cutting of Ti4822 titanium alloy: Cutting performance,chip morphology,and surface quality

A Ti–48Al–2Cr–2Nb (Ti4822) titanium alloy holds great potential for aerospace engine applications, but still faces challenges in safe large-scale production and high processing difficulty. This study employs a one-step in-furnace self-propagating high-temperature synthesis technique for material preparation, overcoming the inherent intense explosive reactions in traditional methods. This approach enables safe continuous production of kilogram-scale γ-TiAl alloys, providing a high-quality material foundation for subsequent processing. This work conducted a study on the effects of ultrasonic vibration-assisted cutting (UC) and conventional cutting on Ti4822 alloy machinability, chip morphology, and surface quality. For the first time, an online observation method of digital image correlation (DIC) was utilized to reveal the strain distribution pattern under ultrasonic vibration, and the weight of the influence of process factors on the processing quality was provided through gray correlation analysis. Observations and quantitative analysis indicate that UC can reduce cutting force by up to 11.91%; DIC dynamic full-field strain shows a maximum Y-direction strain reduction of 53.04%, significantly alleviating stress concentration; chips transition from large fragments to fine, short strips, ensuring smooth chip evacuation without accumulation; and surface roughness is reduced by up to 54.77%, with a surface damage area decreasing by 20.9%. Independent samples t tests confirmed statistical significance. Gray relational analysis ranked the influence weights on machining performance, and UC exhibits a significant positive synergistic effect with a 20° large rake angle tool. These findings provide theoretical support for the efficient and precision machining of this alloy.