Fabrication and evaluation of SixNy coatings for total joint replacements

Abstract

Wear particles from the bearing surfaces of joint implants are one of the main limiting factors for total implant longevity. Si(3)N(4) is a potential wear resistant alternative for total joint replacements. In this study, Si(x)N(y)-coatings were deposited on cobalt chromium-discs and Si-wafers by a physical vapour deposition process. The tribological properties, as well as surface appearance, chemical composition, phase composition, structure and hardness of these coatings were analysed. The coatings were found to be amorphous or nanocrystalline, with a hardness and coefficient of friction against Si(3)N(4) similar to that found for bulk Si(3)N(4). The low wear rate of the coatings indicates that they have a potential as bearing surfaces of joint replacements. The adhesion to the substrates remains to be improved.

Mechanical and tribological behavior of silicon nitride and silicon carbon nitride coatings for total joint replacements

“…In relation to r.f. sputtered Si x N y coatings in a study by (Olofsson et al, 2012), the wear rates with the HiPIMS deposited Si x N y coatings had similar to slightly lower wear rates, although the friction were somewhat higher in this study. Coatings deposited at lower Si target power had a slightly lower wear rate, these coatings also show the highest hardness, as discussed.…”

“…The hardness and elastic modulus of the Si x N y and Si x C y N z coatings (especially for coatings with a low C content) was similar to literature data for coatings deposited using different sputtering methods (DC, r.f. and HiPIMS) (Olofsson et al, 2012;Pusch et al, 2011;Shi et al, 2012). The coatings differed in thickness, consequently the failure loads (L c1 and L c2 ) were not compared.…”

“…Additionally, density functional theory (DFT) calculations have shown that small amounts of substitutionally-bonded carbon can destabilize crystalline Si 3 N 4 , indicating the possibility to tune the dissolution rate (Olofsson et al, 2012). To this date, there have only been a few publications on silicon nitride (Si x N y ) and silicon carbon nitride (Si x C y N z ) coatings for joint implants (Olofsson et al, 2012;Shi et al, 2011Shi et al, , 2012. Olofsson et al (2012) used reactive radio frequency (r.f.)…”

“…To this date, there have only been a few publications on silicon nitride (Si x N y ) and silicon carbon nitride (Si x C y N z ) coatings for joint implants (Olofsson et al, 2012;Shi et al, 2011Shi et al, , 2012. Olofsson et al (2012) used reactive radio frequency (r.f.) sputtering to produce Si x N y and Si x C y N z coatings that showed a potential for high wear resistance, but issues with coating defects and poor adhesion leading to flaking off of the coatings were reported.…”

Effects of coating with different ceromers on the impact strength, transverse strength and elastic modulus of polymethyl methacrylate

“…These processes include physical and chemical vapor deposition [14][15][16][17][18] , ion-assisted deposition (IAD) 19) , plasma immersion ion implantation 20,21) , laser surface alloying 22) , thermal oxidation 23) , sol-gel technique [24][25][26][27][28] , and plasma spray coating techniques 24,29,30) . Each technique presents both advantages and disadvantages 24) .…”