The influence of etching parameters on the roughness changes of the surfaces of medical alloys

U teorijskom dijelu ovog rada prikazan je pregled zahtijevanih svojstava za implantate i osvrt na biomaterijale u ortopediji, s naglaskom na titanijeve i kobalt-krom legure. Ukratko je objašnjen postupak plazmom potpomognutog prevlačenja iz parne faze (PACVD), važnost i vrste pripreme površine prije prevlačenja te najčešće korištena prevlaka nanesena PACVD postupkom, titanijev nitrid (TiN). U eksperimentalnom dijelu rada provedena su mjerenja hrapavosti površine medicinskih legura Ti-6Al-4V ELI i ASTM F1537 nakon tri različite vrste mehaničke obrade uzoraka, i nakon kemijskog, odnosno elektrokemijskog nagrizanja površine uzoraka. Mikrostrukture i površine uzoraka analizirana su primjenom skenirajuće elektronske mikroskopije (SEM). Utvrđeno je da se hrapavost površine uzoraka Ti-6Al-4V ELI povećava duljim trajanjem kemijskog poliranja. Hrapavost površine uzoraka legure ASTM F1537 raste povećanjem napona izvora električne struje i duljinom trajanja elektronagrizanja.First part of this paper gives a review of required properties for medical implants materials and an insight into biomaterials in orthopedics, with an emphasis on titanium and cobalt-chromium alloys. Brief explanation of Plasma Assisted Chemical Vapour Deposition (PACVD) surface treatment is given, along with the importance of various substrate surface pretreatment processes and most commonly used coating, titanium nitride (TiN).In second part, surface roughness measurement for Ti-6Al-4V ELI and ASTM F1537 medical alloys samples was carried out, after three different mechanical surface pretreatment processes, and after chemical and electrochemical polishing. Microstructures and surface roughnesses were analyzed using Scanning Electrone Microscope (SEM). It was determined that longer duration of chemical polishing process increases surface roughness of Ti-6Al-4V ELI samples. Surface roughness of ASTM F1537 samples also increases with higher voltage and longer duration of electropolishing procedure