Papers by Author: M. Jurczyk

Abstract: Titanium and its alloys are common in medical implant applications because of their desirable properties, such as relatively low Young’s modulus, good fatigue strength, corrosion resistance, biocompatibility as well as formability and machinability. However, these materials cannot meet all of the clinical requirements. Current research focuses on improving not only the mechanical performance but mostly the biocompatibility of Ti-based systems through variations in alloy composition and surface treatment. One of the methods that allows the change of biological properties of Ti surface is the modification of its chemical composition. In this work plasma surface modification approach was used to improve mechanical properties by synthesis of composite layer structure on a pure titanium surface. The study aims at development of TiB precipitation dispersed uniformly at α-Ti matrix by plasma melting of Ti-2 wt% and Ti-10 wt% B alloy powders composition. Grain size of precursor powders obtained by mechanical alloying method and its homogenization can control the porosity and boron agglomeration tendency of the synthesized layers. Plasma procedure was taken under argon and helium inert atmosphere and surface was obtained by single passage of plasma pillar upon the prepared surface. The Vickers microhardness of obtained surface reached nearly 850HV, which was much higher compared with initial sample of the pure titanium substrate of 160HV. The surface corrosion resistance in 0.9% NaCl solution was nearly the same as for pure titanium, showing stable behaviour of created oxide layer, with no negative effect of dual phase microstructure. In vitro biocompatibility test in static condition was performed. All samples showed good cell growth. Our studies suggests that chemical composition of modified titanium surface by TiB precipitation by plasma alloying process has no negative effect on cytocompatibility.

Abstract: Formation of porous TiOx layers on Ti during electrochemical etching in H3PO4, CH3COOH electrolytes modified by HF and NH4F was described. The anodization resulted in porous TiOx formation, useful in tissue growth and bone bonding. The pore dimensions increased due to the increase of HF or NH4F content in H3PO4 electrolyte. During anodization at 10 V for 30 min, when the HF content increased from 0.5 to 10%, the pore diameter increased from 30 nm up to 8 m, respectively. Anodization in CH3COOH electrolyte resulted in non-uniform etching with flat hexagonal islands with nanopores inside surrounded by micropores. Corrosion properties of the etched samples were investigated in Ringer’s solution at 37oC and were compared to the unetched sample. The best corrosion resistance showed the samples etched at 10 V for 30 min in 1M H3PO4 + 2% HF and 1M H3PO4 + 10% NH4F, what can be attributed to thick oxide layer. We find, that porous sample presented good biocompatibility with human osteoblasts.