Increasing the Service Life of Solid Ceramic End Mills by Treating Their Surfaces with Fast Argon Atoms

Commercially available solid ceramic end mills, which are remarkable for producing high-quality machined surfaces and achieving cutting speeds unattainable with tungsten carbide tools, are characterized by a wide range of mean times between failures, indicating their low reliability. The primary cause is surface defects generated by diamond grinding during the manufacturing of the mills. In the present study, it is proposed to remove the defective layer by sputtering it with a beam of fast argon atoms, which at the same time appreciably sharpens the cutting edges of the mill. The combined treatment of SiAlON ceramic end mills comprising the removal of a 5 µm thick surface layer and subsequent deposition of a 3 µm thick wear-resistant coating significantly reduces tool wear and increases the average tool life by 1.7 times compared to untreated mills.