Femtosecond laser processing of nitride-based thin films to improve their tribological performance

The ability of femtosecond laser pulses to pattern coated tribological surfaces in order to improve their wear behavior was investigated. Experiments were performed with a Ti:sapphire laser (wavelength: 800 nm, energy density: 2 J/cm2, pulse duration: 100 fs) on TiN- and on TiCN-coated surfaces. Morphological analyses of the laser-treated surfaces were carried out and did not reveal any film delamination or other coating damage after laser processing. Tribological tests simulating rapidly increasing contact pressures under boundary friction were performed on both unpatterned and laser-patterned coated surfaces using a steel counter body. The patterned surfaces showed significantly better tribological performance with respect to stability and the value of the friction coefficient during testing. EDX analyses of the tested unpatterned samples revealed complete coating removal and material transfer from the counter body to the sample surface. In the case of the laser-patterned surfaces, only slight coating damage and an accumulation of debris from the steel counter body in the laser-induced pores were observed.

[1]  Izhak Etsion,et al.  Friction-Reducing Surface-Texturing in Reciprocating Automotive Components , 2001 .

[2]  T. Mang,et al.  Lubricants and Lubrication , 2006 .

[3]  Valerio Romano,et al.  Laser microstructuring of steel surfaces for tribological applications , 2000 .

[4]  Valerio Romano,et al.  Laser microstructuring of surfaces for improving their tribological performance , 2001, Other Conferences.

[5]  Niels Bay,et al.  Entrapment and escape of liquid lubricant in metal forming , 1999 .

[6]  Valerio Romano,et al.  Laser ablation and micropatterning of thin TiN coatings , 2000 .

[7]  M. Obara,et al.  Heat effects of metals ablated with femtosecond laser pulses , 2002 .

[8]  Boris N. Chichkov,et al.  Ablation of metals by ultrashort laser pulses , 1997 .

[9]  M. Sentis,et al.  Femtosecond ablation of ultrahard materials , 2002 .

[10]  I. Etsion,et al.  The effect of surface regular microtopography on fretting fatigue life , 2002 .

[11]  Kôji Katô,et al.  The effects of texture height and thickness of amorphous carbon nitride coating of a hard disk slider on the friction and wear of the slider against a disk , 2000 .

[12]  G. S. Upadhyaya.  Sintered metallic and ceramic materials : preparation, proerties and applications , 2000 .

[13]  Izhak Etsion,et al.  Analytical and Experimental Investigation of Laser-Textured Mechanical Seal Faces , 1999 .

[14]  Heinz Sturm,et al.  Chemical, morphological and accumulation phenomena in ultrashort-pulse laser ablation of TiN in air , 2000 .

[16]  Kôji Katô,et al.  Loads carrying capacity map for the surface texture design of SiC thrust bearing sliding in water , 2003 .

[17]  Izhak Etsion,et al.  Experimental Investigation of Laser Surface Texturing for Reciprocating Automotive Components , 2002 .