Diamond cutting and compliant morphable tool polishing of additively manufactured stainless steel

The surfaces of additively manufactured (AMed) workpiece are generally very rough with many large pits and powder particles, which significantly limits their application. In this work, diamond cutting and compliant morphable tool polishing were proposed to finish AMed stainless steel. The surface morphology, indentation hardness, and friction coefficient of the as-built, diamond-cut, and polished workpiece were measured and analyzed. The results show that grinding was able to reduce the roughness of the as-built sample to 2.4 mu m. Diamond cutting and polishing significantly reduced the roughness Sa, Sq of the sample from more than 10 mu m to 80 nm, 90 nm and 3 nm, and 5 nm, respectively. Besides, the sample surface protrusions and valleys were significantly reduced from similar to 50 and similar to 30 to similar to 0.6 mu m and similar to 0.3 mu m by diamond cutting and similar to 0.2 mu m and 0.1 mu m by polishing. The 9-mu m abrasive polished surface was flat with some left particles and irregular abrasion marks, while the 0.3-mu m abrasive polished surface was flatter with no observable protrusions or marks. Polishing made the nanoindentation load-depth curves more identical, and increased the indentation hardness and modulus, and decreased the indentation depth than those on the cut surface. The friction coefficients on the as-built surface were 0.64-0.82. Diamond cutting and polishing greatly reduced the friction coefficients to 0.49 and 0.46.