Zkoušení a hodnocení korozní odolnosti vybraných kovových biomateriálů a jejich povrchové úpravy

Abstract

Presented dissertation thesis is dedicated to research of corrosion, biological and selected technological properties of metallic biomaterials and their surface treatment. There were four types of biomaterials evaluated in this thesis: sintered titanium alloys with controlled porosity, austenitic stainless steels, NiTi alloy and commercial purity titanium of grade 4. Corrosion properties of all material types were evaluated by potentiodynamic polarization method, electrochemical impedance spectroscopy was used for determination of electrical parameters of surface layers, contact angle was measured using sessile drop method, pull-out test was used for quantification of adhesion of surface layers and scanning electron resp. optical microscopy was used for image analysis of studied samples. There was relation between volume of sacharose and corrosion properties studied very beginning of experimental part of the thesis. Stainless steels were tested regard to their chemical and electrochemical surface treatment. Dependence of deformation, heat treatment and corrosion properties of NiTi alloy was found and is discussed in this thesis. Titanium and its alloys become very popular field of implantology during last two decades. Main part of this thesis reflects requirements field of implantology connected with functionalization of titanium surfaces by chemical and electrochemical treatment. Main aim of this research was to improve biological properties while maintaining its high corrosion resistance. There was relation found between anodization parameters such as time or voltage and resulting mechanical, electrochemical, biological technological and functional properties of tested samples. Heat treatment of anodized surfaces resulted into crystallization and higher adhesion of oxide surface layer to substrate. Highly porous surface layer was saturated by solution of Amoxicillin, which resulted into highly biocompatible surface with significant antibacterial effect. Final part of this thesis is focused on electrochemical method of titanium surface colouring, which allowed to create various shades of colour and also improved corrosion properties.