Microstructure and Mechanical Properties of Laser Surface-Treated Ti13Nb13Zr Alloy with MWCNTs Coatings

Abstract

Laser surface modification of titanium alloys is one of the main methods of improving the properties of titanium alloys used in implantology. This study investigates the microstructural morphology of a laser-modified surface layer on a Ti13Nb13Zr alloy with and without a carbon nanotube coating deposited by electrophoretic deposition. Laser modification was performed for samples with and without carbon nanotube coating for two different laser powers of 800 W and 900 W and for different scan rates: 3 mm/s or 6 mm/s at 25 Hz, and the pulse duration was 2.25 ms or 3.25 ms. A scanning electron microscope SEM was used to evaluate the surface structure of the modified samples. To observe the heat-affected zones of the individual samples, metallographic samples were taken and observed under an optical microscope. Surface wettability tests were performed using a goniometer. A surface roughness test using a profilograph and a nanoindentation test by NanoTest™ Vantage was also performed. Observations of the microstructure allowed to state that for higher laser powers the surfaces of the samples are more homogeneous without defects, while for lower laser powers the path of the laser beam is clearer and more regular. Examination of the microstructure of the cross-sections indicated that the samples on which the carbon nanotube coating was deposited are characterized by a wider heat affected zone, and for the samples modified at 800 W and a feed rate of 3 mm/s the widest heat affected zone is observed. The wettability tests revealed that all the samples exhibit hydrophilic surfaces and the samples with deposited carbon nanotube coating increase it further. Surface roughness testing showed a significant increase in Ra for the laser-modified samples, and the presence of carbon nanotubes further increased this value. Nanoindentation studies showed that the laser modification and the presence of carbon coating improved the mechanical properties of the samples due to their strength.

Influence of Laser Modification on the Surface Character of Biomaterials: Titanium and Its Alloys—A Review

“…A systematic review [119] and research by the authors [10,105,[120][121][122] on the various techniques of the surface modification of titanium have observed an increase in the hardness of materials as a result of laser modification, which has its theoretical basis in [123], where it was indicated that by using a heat source it was possible to control changes in the hardness of materials. Table 4 shows the hardness values obtained for modified titanium alloys and pure titanium using different laser types and parameters.…”

“…Researchers mainly use lasers such as a femtosecond laser [6], Nd: YAG laser [7][8][9][10], CO 2 laser [11], diode [12,13], and fiber laser [14]. Firstly, they provide the possibility to carry out modification processes by adding a coating of the same or another material.…”

Modification of Microstructure and Surface Properties of Ti-6Al-4V Alloy by MoSi2 Particles Using Micro-Arc Oxidation Process

“…Titanium and its alloys such as Ti-6Al-4V as lightweight metals of high relative mechanical strength and fatigue limit, unique properties, including superior biocompatibility, superconductivity, and shape memory, are widely employed in the aerospace, medical equipment, and chemical industries, marine applications at moderate costs, and are found in different branches of modern industry [1][2][3][4][5]. However, these alloys can't be used into mechanical parts that are prone to friction, due to their tribological nature.…”

Mechanical Properties of Titanium Grade 1 After Laser Shock Wave Treatment

“…Under these irradiation conditions, a shock wave is generated near the surface of the sample, the front propagation of which changes the properties of the material [18,19]. In experiments with a laser shockwave, which differs from other methods of generating shockwaves, it is fundamentally simplified to obtain the shape of the wavefront -flat, cylindrical, spherical, as well as the number of shock pulses, since the first of them depends only on the shape of the absorbing surface, and the second one on the selection and adjustment of the optical emitter and modulator of the Q factor [20][21][22]. Nanosecond laser treatment of titanium has found its application in medicine and dentistry.…”