Bulk metallic glasses (BMGs) with amorphous structure have excellent mechanical and chemical properties. In polishing process, it is hard but important to maintain amorphous state to keep original properties of BMGs, which are easily crystallized in traditional mechanical polishing and long-pulse laser polishing. In this paper, we first propose to use femtosecond laser double-pulse irradiation to smooth the surface of Zr-based BMG and make it free of laser-induced periodic surface structures and crystallization. Here, the smooth surface with half decreasing in roughness (Sa) to 111 nm is achieved by optimized parameters with laser pulse energy 0.06 μJ of the first pulse, energy ratio 40% of the first to the second pulse and time delay 20 ps. Obvious transition from a coarse surface to a smooth one occurs at near 10 ps time delay and 40% energy ratio. Mobility enhancement of molten materials guarantees the removal of undesirable surface structures through surface tension and gravity. Crystallization is avoided due to rapid heating and cooling under femtosecond laser double-pulse irradiation. A smoothed BMG surface obtained by this method verifies its feasibility in BMGs polishing.

具有非晶结构的大块金属玻璃（BMG）具有出色的机械和化学性能。在抛光过程中，保持非晶态以保持BMG的原始特性非常困难但很重要，而BMG在传统的机械抛光和长脉冲激光抛光中很容易结晶。在本文中，我们首先建议使用飞秒激光双脉冲辐照来平滑Zr基BMG的表面，使其没有激光引起的周期性表面结构和结晶。在此，通过优化参数实现了粗糙度（Sa）减小一半至111 nm的光滑表面，其中第一脉冲的激光脉冲能量为0.06μJ，第一脉冲与第二脉冲的能量比为40％，延迟时间为20 ps。从粗糙表面到光滑表面的明显过渡发生在接近10 ps的时间延迟和40％的能量比。熔融材料的流动性增强可确保通过表面张力和重力去除不良的表面结构。由于飞秒激光双脉冲辐照下的快速加热和冷却，避免了结晶。通过这种方法获得的平滑的BMG表面证明了其在BMG抛光中的可行性。