Large current ion beam polishing and characterization of mechanically finished titanium alloy (Ti6Al4V) surface

Abstract

Ti6Al4V samples with a surface roughness of about 0.2 μm were polished by a high fluence ion beam source, and influences of the ion current, energy and incident angle on the surface roughness of Ti6Al4V were studied. The as-polished surfaces were characterized by laser scanning confocal microscopy (LSCM), atomic force microscopy (AFM), grazing incidence X-ray diffraction (GIXRD) and X-ray photoelectron spectroscopy (XPS). The LSCM images revealed that the density of pits in the original surface decreased greatly after the ion polishing process. In addition, the surface roughness calculated from these images proved that the mean value reduced to 53 nm with an ion energy, current and incident angle of 600 eV, 130 mA and 75°, respectively. The smoothing effect was also confirmed by the power spectral density (PSD) functions calculated from the AFM data. GIXRD patterns indicated that the Ti6Al4V samples mainly contain the hexagonal close packed (HCP) α-Ti, no recognizable peaks corresponding to the body centered cubic (BCC) β-Ti were observed. Furthermore, after the ion beam polishing process, the phase of all the as-polished samples kept steady. The XPS results revealed that C, O, Ti, Al and V were present in both the original as well as the polished samples. In addition, due to the highly reactive characteristics of Ti, Al and V elements, a higher signal for oxygen can also be observed on the outermost surface of the ion beam polished samples. The polishing process of Ti6Al4V surface bombarded by Ar ion beam is also simulated by binary collision approximation (BCA) code SDTrimSP, the effects of ion beam energy and incident angle on the sputtering yield were investigated. The results showed that the sputtering yield of Ti, Al and V atoms increased almost linearly with the ion energy. However, as for the influence of ion incident angle, the sputtering yield first increased gradually from 0° and peaked at about 65°, then decreased rapidly because the incident angle is too large for Ar ion to penetrate into the surface of Ti6Al4V sample.

The Effect of Position of Materials on a Build Platform on the Hardness, Roughness, and Corrosion Resistance of Ti6Al4V Produced by DMLS Technology

“…The resulting roughness of parts produced in an additive way is always the result of a combination of input parameters-in particular, the particle size of the powder used, melting conditions (laser power and speed, laser scanning strategy, layer height), or orientation of the produced part relative to the building platform [6,32,33]. The roughness affects implant-bone interaction, the friction coefficient, osseointegration process [3,34] (especially in porous structures [4][5][6][7]), and the fatigue life of the product [11].…”

Current Status on Pulsed Laser Deposition of Coatings from Animal-Origin Calcium Phosphate Sources

“…Solvents like acetone, ethylic alcohol, and/or distilled water might be used in this case, always keeping in mind the nature and properties of the used substrates. By contrast, more complex substrate preparation techniques include (i) mechanical modification of the surface, by sand-blasting [124], grit-blasting [125,126], polishing [127,128], or grinding [129], and (ii) chemical treatments, modifications, or functionalization, using chemical activation [130], alkaline treatments [131], anodization [124,125], acid-etching [124][125][126], oxidizing [132], and many other actions [124,133]. Additional physical treatments, resulting in various types of surface modifications, were briefly discussed in Reference [133].…”

Material Removal and Surface Integrity Analysis of Ti6Al4V Alloy after Polishing by Flexible Tools with Different Rigidity

“…Furthermore, Ti6Al4V is commonly used in the biomedical field due to its high biocompatibility [ 11 , 12 ], such as artificial hip joints, compression hip screws, dental implants body, bone plate, heart catheter, artificial heart valve for orthodontic surgery, etc. [ 13 , 14 , 15 , 16 , 17 ]. Furthermore, low surface roughness is usually required to obtain superior functionality for most of its applications, such as implants and turbine blades [ 18 , 19 ].…”