Effect of the surface oxidization and nitridation on the normal spectral emissivity of titanium alloys Ti–6Al–4V at 800–1100 K at a wavelength of 1.5 μm

Effect of oxidation on spectral and integrated emissivity of Ti-6Al-4V alloy at high temperatures

“…Those oscillations are explained by an interference effect within the oxide layer. Oscillations, especially visible in the first 20 min, were also reported by Zhu [29] for a thermal range between 527 and 827 °C and a wavelength of 1.5 µm. Transus β effect on emissivity was also investigated by some works.…”

“…Oscillations are noticed at 600 and 700 °C which is once again a signature of the semi-transparency of the thin oxide layer. These oscillations disappear after 20 min in the same order of magnitude than Li [28] and Zhu [29] works. Temperature has a strong influence under 800 °C but is less significant beyond, where the oxide layer thickness is superior to the photon average free path.…”

“…The temperature range was chosen to overlap several hot forming applications like forging, hot stamping, SPF forming… Heating time of one hour was chosen which allows applying those measurements for rapid processes like forging or slower processes like IR SPF forming. However, some works in literature [28,29] have shown that TA6V emissivity between 600 and 827 °C grows steadily until 200 min of heating but much slowly beyond. Therefore, a whole heating time of five hours at 1000 °C was added in order to highlight its effect on emissivity value.…”

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

“…In addition, titanium alloys have been oxidized in an acid solution in the presence of fluoride ions to obtain a nanoparticle oxide layer with good adhesion, high mechanical properties and increased bioactivity [12]. The improvement of titanium biomaterials properties has been obtained by subjecting them to ion implantation [13,14], plating [15,16] and nitriding [17,18]. A popular method of obtaining better properties of the titanium alloys tested is coating them using silicates [19], chitosan [20,21], or phosphates including hydroxyapatite (HAp) [22][23][24][25] and nanoHAp [7,[26][27][28]-together with their composite combinations with other elements [26,[28][29][30][31][32][33]-thus facilitating better adhesion and antibacterial properties.…”