Enhanced toughness and skin grafting durability of a dermatome made of Fe-based bulk metallic glass composites

Based on the concept of dispersion toughening on the bulk metallic glass composites (BMGCs), a series of Fe-based BMGC5 with compositions of (Fe41Cr15Co7Mo14C12B9Y2)(100-x) Ta-x(x = 2-5) were successfully fabricated by arc-melting and suction casting method. The excess of Ta was revealed to form one kind of fine Ta-rich precipitate and distributed homogeneously in the amorphous matrix. Accordingly, the alloy composition of Fe-based BMGC were further modified by adding 3.5 at% Ta to replace the content of boron and carbon, and fabricate into the Fe41Cr15Co7Mo14C10B7.5Y2Ta3.5 (Fe41C10B7.5Ta3.5) BMGC rod. As a result, the fracture toughness of this Fe41C10B7.5Ta3.5 BMGC was significantly improved to 10.2 MPa.root m, which is about twice values of the Fe-base BMG without Ta content. Fe41C10B7.5Ta3.5 BMGC dermatome exhibits much higher sharpness than the commercial one on the simulated skin grafting test because of its lower surface roughness and higher hardness. Moreover, the Fe41C10B7.5Ta3.5 BMGC dermatome presents much better durability on simulated skin grafting test, it can remain sharper edge-tip with a low blade sharpness index (BSI) value of 0.35 (in comparison with the BSI value of 0.59 for commercial blades) after the skin grafting test over 15 cm length.