Design and fabrication of ultra-small micro end-mills for the machining of bone tissue

Ultra-small micro end mills are widely used in micro-precision machining of medical bone tissue. However, there are still many challenges in the design and fabraction of ultra-small micro end-mills for biomedical. To improve the cutting performance of the micro end mills in micro machining of bone tissue, the optimization geometry design of the ultra-small micro end mills is studied. Three different shapes ultra-small micro end -mills (helical-type, Δ-type, and □-type) with the diameter of 50 μm are designed and manufactured by precision grinding. The strength and stiffness of the ultra-small micro end mills are analyzed by finite element analysis (FEA). The results show that the tool tip rigidity of the Δ-type and □-type is much higher than other helical-type micro end mills. The micro slot milling experiment on bone issue is carried out to compare their cutting performance. It is proposed that the Δ-type micro end mills can reduce the machining damage and improve the machining quality of bone tissue.