Friction-Stir Nitriding of Titanium Alloy Surface Layer

The paper reports the results of a study on the Ti6Al4V titanium alloy involving the XPS (X-ray photoelectron spectroscopy) photoelectron spectroscopy method. The position of bands in the viewing spectrum serves as a basis for the qualitative identification of atoms forming the surface layer, while their intensity is used to calculate the aggregate concentration of these atoms in the analyzed layer. High-resolution spectra are used to determine the type of chemical bonds based on characteristic numerical values of the chemical shift. The paper also presents the 3D results of surface roughness measurements obtained from optical profiling, as well as the results of energy state measurements of the Ti6Al4V titanium alloy surface layer after ozone treatment. It was shown that the ozone treatment of the Ti6Al4V titanium alloy removes carbon and increases concentrations of Ti and V ions at higher oxidation states at the expense of metal atoms and lower valence ions. The modification of the surface layer in ozone atmosphere caused a 30% increase in the Ti element concentration in the surface layer compared to the samples prior to ozone treatment. The carbon removal rate from the Ti6Al4V titanium alloy samples amounted to 35%, and a 13% increase was noted in oxides. The tests proved that the value of the surface free energy of the Ti6Al4V titanium alloy increased as a result of ozone treatment. The highest increase in the surface free energy was observed for Variant 4 samples, and amounted to 17% compared to the untreated samples, while the lowest increase was equal to 14%. For the analyzed data, the maximum value of standard deviation was 0.99 [mJ/m2].

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Utilisation of High-Energy Heat Sources in Magnesium Alloy Surface Layer Treatment

Archives of Metallurgy and Materials ◽

10.2478/amm-2013-0047 ◽

2013 ◽

Vol 58 (2) ◽

pp. 619-624 ◽

Cited By ~ 2

Author(s):

M. Szafarska ◽

J. Iwaszko ◽

K. Kudła ◽

I. Łegowik

Keyword(s):

Surface Layer ◽

Magnesium Alloy ◽

Physicochemical Properties ◽

Treatment Effectiveness ◽

High Energy ◽

Alloy Surface ◽

Heat Sources ◽

X Ray ◽

Additional Equipment ◽

Alloy Surface Layer

The main aim of the study was the evaluation of magnesium alloy surface treatment effectiveness using high-energy heat sources, i.e. a Yb-YAG Disk Laser and the GTAW method. The AZ91 and AM60 commercial magnesium alloys were subject to surface layer modification. Because of the physicochemical properties of the materials studied in case of the GTAW method, it was necessary to provide the welding stand with additional equipment. A novel two-torch set with torches operating in tandem was developed within the experiment. The effectiveness of specimen remelting using a laser and the GTAW method was verified based on macro- and microscopic examinations as well as in X-ray phase analysis and hardness measurements. In addition, the remelting parameters were optimised. The proposed treatment methodology enabled the achieving of the intended result and effective modification of a magnesium alloy surface layer.

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Phase and structural states in the NiTi-based alloy surface layer formed by electron-ion-plasma methods using tantalum

10.1063/1.4932852 ◽

2015 ◽

Author(s):

Aleksei A. Neiman ◽

Ludmila L. Meisner ◽

Aleksandr I. Lotkov ◽

Ekaterina Y. Gudimova ◽

Viktor O. Semin

Keyword(s):

Surface Layer ◽

Alloy Surface ◽

Ion Plasma ◽

Plasma Methods ◽

Alloy Surface Layer

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Structural Aspects of Remelting of the AZ91 Magnesium Alloy Surface Layer

Archives of Foundry Engineering ◽

10.1515/afe-2015-0095 ◽

2016 ◽

Vol 16 (1) ◽

pp. 13-18

Author(s):

J. Iwaszko ◽

M. Strzelecka

Keyword(s):

Surface Layer ◽

Magnesium Alloy ◽

Structural Changes ◽

Continuous Wave ◽

Sample Surface ◽

Alloy Surface ◽

Az91 Alloy ◽

Az91 Magnesium Alloy ◽

Az91 Magnesium ◽

Alloy Surface Layer

Abstract In this study, modification of the AZ91 magnesium alloy surface layer with a CO2 continuous wave operation laser has been taken on. The extent and character of structural changes generated in the surface layer of the material was being assessed on the basis of both macro- and microscopy investigations, and the EDX analysis. Considerable changes in the structure of the AZ91 alloy surface layer and the morphology of phases have been found. The remelting processing was accompanied by a strong refinement of the structure and a more uniform distribution of individual phases. The conducted investigations showed that the remelting zone dimensions are a result of the process parameters, and that they can be controlled by an appropriate combination of basic remelting parameters, i.e. the laser power, the distance from the sample surface, and the scanning rate. The investigations and the obtained results revealed the possibility of an effective modification of the AZ91 magnesium alloy surface layer in the process of remelting carried out with a CO2 laser beam.

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Modification of Al-Si alloy surface layer using Nd:YAG laser

10.1117/12.726543 ◽

2006 ◽

Author(s):

Agnieszka E. Radziszewska ◽

Sławomir Z. Kąc

Keyword(s):

Surface Layer ◽

Nd:Yag Laser ◽

Alloy Surface ◽

Alloy Surface Layer

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Study on Rare Earth Catalysis in the Boriding Process to Titanium Alloy

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.48-49.1177 ◽

2011 ◽

Vol 48-49 ◽

pp. 1177-1181

Author(s):

Feng Hua Li ◽

Xiao Hong Yi ◽

Jing Lei Zhang ◽

Zhan Guo Fan

Keyword(s):

Titanium Alloy ◽

Surface Layer ◽

Rare Earth ◽

Phase Composition ◽

Diffusion Layer ◽

Alloy Surface ◽

Tc4 Titanium Alloy ◽

Boriding Process

Solid powder boriding experiment was carried out on TC4 titanium alloy surface with method of RE(rare earth)-boriding at the temperature of over 1000°C. By means of XRD, SEM and EDS, phase composition, microstructure and morphology of TC4 titanium alloy after RE-boriding were investigated. The effect of rare earth on phase composition was discussed. Results of the experiment showed that the diffusion layer was composed of top-layer TiB2 and sub-layer TiB whiskers with the highest thickness being 25μm. The XRD results revealed TiB-TiB2 biphasic B-Ti compounds layer formed on the surface of TC4 after RE-boriding. The high content of B and Ce in the surface layer showed rare earth increased the absorption and concentration of B atoms.

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