Faculty of Mechanical Engineering, Department of Materials Engineering and Biomaterials, Silesian University of Technology, Konarskiego 18A Street, 44-100 Gliwice, Poland
Prof. Mirosław Bonek
Faculty of Mechanical Engineering, Department of Materials Engineering and Biomaterials, Silesian University of Technology, Konarskiego 18A Street, 44-100 Gliwice, Poland
The human body is an extremely aggressive environment in terms of corrosion. Titanium and its alloys are one of the most popular biomaterials used for implant applications due to biocompatibility. However, every element introduced into the body is treated as a foreign body. The human body’s immune response may, therefore, lead to implant rejection and the need for reoperation. For this purpose, it seems important to carry out surface modifications by applying coatings and inter alia by texturing to implants. The objective of this paper is to investigate the effect of surface treatment on the chosen properties of the pure titanium (Grade II) samples obtained by selective laser melting (SLM) processing. The samples were divided into five groups: Initial state (after polishing), after surface modification by the physical vapour deposition (PVD) method—CrN and TiN coatings were deposited on the surface of the tested material, and after laser texturing. The paper presents the results of the microscopic investigation, chemical and phase compositions, and physicochemical and electrochemical properties of the tested samples. Based on the results obtained it can be concluded that the hybrid surface modification shows significant effects on the properties of the pure titanium. The samples with the textured PVD-deposited TiN coatings were characterized by favorable physicochemical properties and were the highest performing in terms of pitting corrosion resistance.
The laser surface remelting (LSR) process was successfully applied to restore localized corrosion resistance in sensitized stainless steel and also as a useful method to improve passivity of some martensitic stainless steels. The LSR process can be successfully applied to repair cracks and defects at the surface of highly thermo-mechanically loaded parts of stainless steel. The purpose of presented study was to evaluate the microstructure and properties of laser remelted surface of stainless steels. The wrought austenitic stainless steel and sintered in vacuum 316L type were studied. The laser treatment was performed with the use of high power diode laser (HPDL) and the influence of beam power of 0.7-2.1kW on the properties of the surface layer was evaluated. The geometrical characteristics and x-ray analysis of weld bead were studied as well as microhardness, surface roughness and corrosion resistance were measured. The increase of laser beam power of LSR resulted in the increase of hardness of sintered stainless steel due to the reduction of porosity and formation of fine dendritic and cellular-dendritic microstructure. The corrosion resistance of remelted surface increased for sintered materials, when remelted at 2.1kW. The wrought stainless steel revealed impairment of pitting corrosion when remelted at lower beam power rate.
1 May 2005 in Journal of Materials Processing Technology