Surface Integrity of Ultrasonically-Assisted Milled Ti6Al4V Alloy Manufactured by Selective Laser Melting

Chinese Journal of Mechanical Engineering

Sai Guo¹  Qinghong Jiang¹  Bi Zhang¹  Zhigang Dong²  Wei Du³ 

[1]Department of Mechanical and Energy Engineering, Southern University of Science and Technology, 518055, Shenzhen, China

[2]Key Laboratory for Precision and Non-Traditional Machining Technology of Ministry of Education, Dalian University of Technology, 116024, Dalian, China

[3]School of Mechanical Engineering, Dalian University of Technology, 116024, Dalian, China

关键词: Ultrasonically-assisted vertical milling;    Surface integrity;    Ti6Al4V;    Selective laser melting;   

DOI  :  10.1186/s10033-021-00586-z

来源: Springer

【 摘 要 】

The Ti6Al4V parts produced by the existing selective laser melting (SLM) are mainly confronted with poor surface finish and inevitable interior defects, which substantially deteriorates the mechanical properties and performances of the parts. In this regard, ultrasonically-assisted machining (UAM) technique is commonly introduced to improve the machining quality due to its merits in increasing tool life and reducing cutting force. However, most of the previous studies focus on the performance of UAM with ultrasonic vibrations applied in the tangential and feed directions, whereas few of them on the impact of ultrasonic vibration along the vertical direction. In this study, the effects of feed rate on surface integrity in ultrasonically-assisted vertical milling (UAVM) of the Ti6Al4V alloy manufactured by SLM were systemically investigated compared with the conventional machining (CM) method. The results revealed that the milling forces in UAVM showed a lower amplitude than that in CM due to the intermittent cutting style. The surface roughness values of the parts produced by UAVM were generally greater than that by CM owing to the extra sinusoidal vibration textures induced by the milling cutter. Moreover, the extra vertical ultrasonic vibration in UAVM was beneficial to suppressing machining chatter. As feed rate increased, surface microhardness and thickness of the plastic deformation zone in CM raised due to more intensive plastic deformation, while these two material properties in UAVM were reduced owing to the mitigated impact effect by the high-frequency vibration of the milling cutter. Therefore, the improved surface microhardness and reduced thickness of the subsurface deformation layer in UAVM were ascribed to the vertical high-frequency impact of the milling cutter in UAVM. In general, the results of this study provided an in-depth understanding in UAVM of Ti6Al4V parts manufactured by SLM.

【 授权许可】

CC BY