Abrasive wear behavior under metal cutting conditions

The tribological system of metal cutting is characterized by severe conditions. High stresses and seizure as well as high temperatures and freshly generated surfaces define a unique tribosystem. Therefore, many tribological tests at low relative speeds and temperatures do not represent metal cutting conditions and the derivation of quantitative relationships for friction and wear is hardly possible. By means of powder metallurgy a ferritic-pearlitic steel with varying content of abrasive Al2O3 particles has been manufactured and machined in order to investigate abrasive wear under metal cutting conditions for coated as well as uncoated cutting tools. A sample without any abrasive particles is used as a reference to quantify the effect of the addition of 0.5 wt%, 1 wt% and 2 wt% of Al2O3 in the workmaterial. Whereas on the flank face of the cutting tools, the wear rate progressively increases with the content of abrasive particles, the rake face wear does not depend on the added content of Al2O3. The results show that the abrasive wear rate under metal cutting conditions is high in initial stages but decreases considerably over cutting time. This phenomenon is discussed against the background of machining theory.