Wear behavior of PACVD tin coatings deposited onto tool steels

During cold forming processes like deep drawing of steel sheets, tools are subjected to various loads. During forming, Hertzian contact pressures and frictional forces cause fatigue and adhesion, respectively. Abrasion may ta ke place if wear particles are entrapped in the contact zone. Therefore, th e aim of this work is to evaluate TiN coatings deposited by plasma assisted chemical vapor deposition (PACVD) onto tool steels with respect to adhesio n, fatigue wear properties. Stoichiometric TiN coatings with different morp hologies were deposited with and without plasma-nitriding of the steel subs trate and characterized by X-ray diffraction (XRD) and scanning electron mi crosopy. The adhesion of the coatings was investigated using the VDI indent ion test and a surface fatigue test, where cyclic loads up to 80 kN are app lied to the tool surface by cylindrical indenters. Adhesive wear of the coa tings have been evaluated using a ball-on-disc tribometer. Abrasion resista nce was characterized using a small-scale abrasive wear test.