Mechanical properties of TiN coatings deposited at different temperatures by IBAD process

Abstract

TiN coatings were deposited on hot working steel substrates by ion beam assisted deposition technique. The deposition process was conducted at two different temperatures 50 and 400 ºC. The influence of applied deposition temperature on the mechanical properties, adhesion strength and surface morphology of TiN coatings was studied. The mechanical properties, i.e. hardness, modulus of elasticity and coating strength were characterized by nano-indentation technique. Adhesion strength was evaluated by generally accepted scratch test technique. In addition, HRC adhesion test was utilized to compare adhesion of different coatings qualitatively. Surface morphology was analyzed by atomic force microscopy before and after the film deposition. The coating deposited at higher temperature displayed higher hardness, and also higher critical loads were obtained during scratch test, when compared to coating deposited at lower temperature. The ion bombardment during the deposition process enhances the adatom mobility allowing the deposition of coatings with high hardness and adhesion strength even at low temperatures.

Keywords

• tin
• ibad
• deposition temperature
• afm
• surface roughness