Investigation of Element Profiles, Defects, Phase Composition and Physical and Mechanical Properties of Superhard Coatings Ti-Hf-Si-N

Alexander D. Pogrebnjak
2013 Materials Sciences and Applications  
This paper investigates the microstructure, physical, chemical and mechanical of superhard nanocomposite of Ti-Hf-Si-N. The coatings were grown by C-PVD method. Profiles of elements and vacancy-type defects (S-parameter measurements of the Doppler broadening of the annihilation peak DBAP) in the studied coatings were investigated. Defined and calculated the elastic modulus E, hardness H, friction, adhesion. Wear rate was determined as a function of the bias potential supplied to the substrate
more » ... to the substrate and the pressure in the chamber. The developed coatings have hardness of 37.8 to 48 GPa, the friction coefficient of 0.48 to 0.15, the grain size of the solid solution from 3.9 to 10.8 nm (depending on deposition conditions). It was found that positrons are trapped by defects at the junction of three or more nanograins interfaces. In some cases, there was formed two phases in coatings: a solid solution (Ti, Hf)N with different volume content of Hf in a solid solution, and an amorphous phase α-Si 3 N 4 (the layer between the nanograins). Figure 3. Images of structure areas of nanocomposite Ti-Hf-Si-N coating, obtained by TEM JEOL 2010 F: (a) structure of surface; (b) dark-field image of nanograin strucure. t
doi:10.4236/msa.2013.44a004 fatcat:673fcehvgzggvaafb4vunmahaa