Ultrasonic elliptical vibration cutting (UEVC) technology has been utilized for ultra-precision machining of difficult-to-machine metal materials such as tungsten. Nevertheless, the microstructure evolution mechanism of tungsten under the synergistic effect of ultrasonic and mechanical loads remains unclear, particularly at the atomic/nano scale. Additionally, the plastic deformation mechanism of tungsten differs from that of other metallic materials due to its low dislocation mobility (brittle at room temperature). Hence, the molecular dynamics simulation of UEVC for single crystal tungsten was established to study its mechanisms in plastic deformation and microstructure evolution under stress induction in this study. The results indicated that the main plastic deformation mechanisms including dislocation slip, amorphous phase transformation and nanocrystal were found during the tungsten removal, and accompanied by some extent of lattice distortion. The instantaneous shear stress of UEVC reached 16.88 GPa. Compared with common cutting (CC), the formation of nanocrystals mainly occurred in UEVC because the instantaneous shear stress exceeded the critical shear stress of multiple slip systems during cutting. Similarly, the high dislocation density and high plastic deformation degree of the machined zone in UEVC were also attributed to the high shear stress. The dynamic recrystallization of tungsten induced by UEVC was realized from dislocation slip to the formation of dense dislocation walls, followed by the formation of sub-grain boundaries, and finally to the formation of nanocrystals.

超声波椭圆振动切割（UEVC）技术已被用于钨等难加工金属材料的超精密加工。尽管如此，钨在超声和机械载荷协同作用下的微观结构演化机制仍不清楚，尤其是在原子/纳米尺度上。此外，钨的塑性变形机制不同于其他金属材料，因为它的位错迁移率低（在室温下很脆）。因此，本研究建立了单晶钨UEVC的分子动力学模拟，以研究其在应力诱导下的塑性变形和微观结构演化机制。结果表明，主要的塑性变形机制包括位错滑移，在脱钨过程中发现了非晶相变和纳米晶，并伴有一定程度的晶格畸变。UEVC的瞬时剪应力达到16.88 GPa。与普通切割（CC）相比，纳米晶体的形成主要发生在UEVC中，因为瞬时剪切应力超过了多个滑移系统在切割过程中的临界剪切应力。同样，UEVC加工区的高位错密度和高塑性变形程度也归因于高剪切应力。UEVC诱导的钨动态再结晶实现了从位错滑移到致密位错壁的形成，再到亚晶界的形成，最后到纳米晶的形成。并伴有一定程度的晶格畸变。UEVC的瞬时剪应力达到16.88 GPa。与普通切割（CC）相比，纳米晶体的形成主要发生在UEVC中，因为瞬时剪切应力超过了多个滑移系统在切割过程中的临界剪切应力。同样，UEVC加工区的高位错密度和高塑性变形程度也归因于高剪切应力。UEVC诱导的钨动态再结晶实现了从位错滑移到致密位错壁的形成，再到亚晶界的形成，最后到纳米晶的形成。并伴有一定程度的晶格畸变。UEVC的瞬时剪应力达到16.88 GPa。与普通切割（CC）相比，纳米晶体的形成主要发生在UEVC中，因为瞬时剪切应力超过了多个滑移系统在切割过程中的临界剪切应力。同样，UEVC加工区的高位错密度和高塑性变形程度也归因于高剪切应力。UEVC诱导的钨动态再结晶实现了从位错滑移到致密位错壁的形成，再到亚晶界的形成，最后到纳米晶的形成。纳米晶体的形成主要发生在UEVC中，因为瞬时剪切应力超过了切割过程中多个滑移系统的临界剪切应力。同样，UEVC加工区的高位错密度和高塑性变形程度也归因于高剪切应力。UEVC诱导的钨动态再结晶实现了从位错滑移到致密位错壁的形成，再到亚晶界的形成，最后到纳米晶的形成。纳米晶体的形成主要发生在UEVC中，因为瞬时剪切应力超过了切割过程中多个滑移系统的临界剪切应力。同样，UEVC加工区的高位错密度和高塑性变形程度也归因于高剪切应力。UEVC诱导的钨动态再结晶实现了从位错滑移到致密位错壁的形成，再到亚晶界的形成，最后到纳米晶的形成。