Surface finish of bulk metallic glass using sequential abrasive jet polishing and annealing processes

Surface finish plays an important role in product quality due to its direct effects on product appearance. Hence, improvement of the surface finish is an essential requirement in industrial products. In an attempt to improve the surface finish of bulk metallic glass (BMG) material, several common methods have been used, such as milling, grinding, and lapping. However, the BMG surface finish has not yet been significantly improved by using these methods. Therefore, this paper proposes sequential abrasive jet polishing (AJP) and annealing processes that can considerably improve the BMG surface finish. In addition, this paper also takes into account optimal parameters for the AJP and annealing processes based on the Taguchi’s L 18 and L 8 orthogonal array experimental results, respectively. The experimental results show that using optimal AJP parameters, the surface roughness ( R a ) of the ground specimens can be significantly improved from 0.675 to 0.016 μm. After the AJP process, the surface roughness ( R a ) of the polished specimens can be further improved from 5.7 to 2 nm within an area of 5 × 5 μm by using optimal annealing parameters.