Comparison of the physicochemical properties of Al2O3 layers applied to the surfaces of cpTi and the Ti6Al7Nb alloy using the ALD method

Abstract

Literature data show that atomic-layer deposition (ALD) is a very important method for depositing layers due to the mechanical and physicochemical properties of the surface. In the literature, little space is devoted to layers of Al2O3, which could also have a major impact on improving the physicochemical properties of metallic biomaterials. Therefore, the aim of this research was to determine the influence of the Al2O3 layer formed by the ALD method on the physicochemical properties of metallic biomaterials. Based on the results, a beneficial effect on the pitting and crevice-corrosion resistance of the applied Al2O3 layer was determined, compared to the initial state, devoid of the layer, regardless of the substrate used. On the other hand, the performed surface-wettability tests showed no influence of the ALD temperature on the obtained angle values. Proposing appropriate conditions for the surface treatment using the ALD method has some promise and will contribute to the development of a technological process with defined parameters for oxide-layer manufacture for implants used in bone surgery. Keywords: cpTi (Grade 4), Ti6Al7Nb alloy, Al 2 O 3 layer, adhesion, corrosion resistance Podatki iz literature ka`ejo, da je depozicija atomskih plasti (ALD) zelo pomembna metoda za nana{anje plasti zaradi mehanskih in fizikalno-kemijskih lastnosti povr{ine. V literaturi so plasti Al2O3 sicer le malo omenjene pa vendar imajo lahko velik vpliv na izbolj{anje fizikalno-kemijskih lastnosti kovinskih biomaterialov. Cilj raziskave je bil zato ugotoviti vpliv Al2O3 sloja, tvorjenega z metodo ALD, na fizikalno-kemijske lastnosti kovinskih biomaterialov. Na osnovi rezultatov smo dolo~ili ugoden u~inek uporabljene Al2O3 plasti pri odpornosti na luknji~asto in {pranjsko korozijo, v primerjavi z za~etnim stanjem, ki je bila brez sloja, ne glede na uporabljeno podlago. Po drugi strani pa so izvedeni testi povr{inske vpojnosti pokazali, da temperatura ALD-metode ne vpliva na dobljene kotne vrednosti. Ustrezni pogoji, predlagani za povr{insko obdelavo z uporabo ALD-metode, veliko obetajo in bodo prispevali k razvoju tehnolo{kega procesa z dolo~enimi parametri za izdelavo vsadkov, ki se uporabljajo v kirur{ki medicini in pri operacijah kosti. Klju~ne besede: cpTi (Grade 4), Ti6Al7Nb zlitina, Al2O3 plast, oprijem, odpornost proti koroziji