A. Zieliński

Effects of Laser Remelting at Cryogenic Conditions on Microstructure and Wear Resistance of the Ti6Al4V Alloy Applied in Medicine

The titanium and its alloys can be subjected to surface treatment, including laser treatment. In this work a new laser treatment at cryogenic conditions of Ti6Al4V alloy has been described. The work has been aimed at establishing whether such surface treatment could be suitable for implants working under wear in biological corrosive environment. The remelting has been made with the use of CO2 continuous work laser at laser power between 3 and 6 kW, at scan rate 0.5 and 1 m/s. The microstructure, surface topography, hardness, microhardness and wear linear rate and mass loss under tribological tests made in Ringer`s solution have been made. The results have shown that despite the surface cracking the tribological properties in simulated body fluid have been substantially improved.

Influence of laser remelting at cryogenic conditions on corrosion resistance of non-ferrous alloys

Influence of laser remelting at cryogenic conditions on corrosion resistance of non-ferrous alloys The main reason for laser remelting of the components made of aluminium, copper and titanium alloys is to obtain high hardness and corrosion resistance at the surface for longer lifetime as result of the rapid solidification. The final microstructure, phase composition and properties of aluminium, copper and titanium alloys depend on the laser process parameters and obviously on the nature of the equilibrium system. The effect of laser surface remelting at cryogenic conditions on the microstructure and corrosion characteristics of the AlSi13Mg1CuNi, SUPERSTON and Ti-6Al-4V alloys are presented. The beneficial effects of laser treatment on the microstructure and corrosion behaviour of those alloys used for different products are observed.

Surface Cracking of Laser Melted Ti-6Al-4V Alloy

Surface Cracking of Laser Melted Ti-6Al-4V Alloy The characteristic features of surface cracking observed after laser melting with CO2 and Nd:YAG laser were described. The cracks were always present, their length approaching some part of melted zone and scarcely dependent on laser melting conditions. The appearance of cracks was attributed mainly to martensitic transformation within the surface layer. The possible contribution of developed thermal stresses cannot be also excluded. The existence of cracks may be utilized for the enhancement of bone - implant strength.

Wpływ modyfikacji laserowej stopu Ti13Nb13Zr na mikrostrukturę powłok hydroksyapatytowych

Dotychczasowe badania powierzchni wszczepow tytanowych dla chirurgii kostnej wykazaly, ze osteointegracja na powierzchniach rozwinietych jest znacznie szybsza niz na powierzchniach gladkich, co za tym idzie chropowatośc powierzchni implantu ma bardzo duzy wplyw na adhezje skladnikow środowiska biologicznego. W artykule przedstawiono wstepne wyniki badan dotyczące wplywu chropowatości powierzchni stopu Ti13Nb13Zr o bardzo malym module Younga na budowe wytworzonej powloki hydroksyapatytowej.

Evaluation of Wear Resistance of Ti Alloys Used for Elements Friction of Knee Endoprosthesis

The paper presents research results of resistance to abrasive wear of titanium alloys: Ti6Al4V (commonly used) and Til3Nb13Zr (alloy of new generation) in association with polyethylene (UHMW-PE) predisposed for elements on pair of the knee endoprosthesis. The results were analysed from the point of possibility of an use of new generation titanium alloys as components of such implants. The tests of resistance to abrasive wear of selected kinematic pairs were conducted with the PT-3 tribometer in Ringer’s solution a constant load 2.0 kN, rotational speed of the rotating specimens (Ti13Nb13Zr and Ti6Al4V) 30 rev/min, and test duration 1 or 2 hrs.