Abstract
Recently, β-type titanium alloy exhibiting super-elasticity and super-plasticity was developed. The excellent characteristics of this alloy indicate its likely application in the field of oral surgery. However, super-elasto-plastic titanium alloy is difficult to cut because of its high adherence and low thermal conductivity. In this study, the effect of tool coating on the tool life and surface roughness were investigated in milling of super-elasto-plastic titanium alloy with a small ball end mill tool. Tool life of AlCrSiN coated tool is longer than TiSiN coated tool and DLC coated tool. The tool wear progress of TiSiN coated tool with flaking. The thickness of DLC coating film is thinner than that of AlCrSiN coated tool. Therefore, the flank wear of DLC coated tool was large. On the other hand, the surface roughness of AlCrSiN coated tool is approximately 2.0 μm in initial cutting. However, it becomes less than 0.8μmRz with increasing cutting length. Thus, AlCrSiN coated tool is expected in view of the tool life and surface roughness.
