Process for deposition of a wear-resistant coating onto a cutting tool made from a carbon-containing material

A process for deposition of a wear-resistant coating onto a cutting tool made from a carbon-containing material comprising the following steps:

• (a) placing said cutting tool into a saturated solution of a salt containing a cation selected from the group consisting of Na, K, Ag, Ca, Ga, Tl, La, Ce, Ta in a contacting zone for a period of from 5 to 10 minutes;
• (b) removing said cutting tool from the contacting zone and evaporating the solvent from said saturated solution on the cutting tool to crystallize the salt on the surface of said cutting tool;
• (c) placing said cutting tool having the salt crystallized on the surface into a vacuum chamber provided with cathodes;
• (d) energizing an arc discharge in said vacuum chamber to evaporate a cathode material of at least one Group IVA, VA or VIA element of the Periodic Table;
• (e) heating said cutting tool by bombardment with ions of said evaporated cathode material to a temperature at which decomposition of said salt occurs to decompose the crystals of said salt;
• (f) switching-off said arc discharge and maintaining said cutting tool for from 15 to 30 seconds at said temperature at which decomposition of said salt occurs;
• (g) re-energizing said arc discharge and heating said cutting tool by bombardment with ions of the evaporated cathode material to a temperature of carbidization of said evaporated cathode material;
• (h) introducing a gas reactant into said vacuum chamber and reacting the ions of the evaporated cathode material with said gas reactant to form the wear-resistant coating on the cutting tool.