Investigating the correlation between nano-impact fracture resistance and hardness/modulus ratio from nanoindentation at 25–500 °C and the fracture resistance and lifetime of cutting tools with Ti1−xAlxN (x=0.5 and 0.67) PVD coatings in milling operations

A novel laboratory technique, nano-impact testing, has been used to test Ti1−xAlxN (x=0.5 and 0.67) PVD coated WC–Co inserts at 25–500 °C. Cutting tool life was studied under conditions of face milling of the structural AISI 1040 steel; the end milling of hardened 4340 steel (HRC 40) and TiAl6V4 alloy. A correlation was found between the results of the rapid nano-impact test and milling tests. When x=0.67 improved resistance to fracture was …