Surface characterization and formation mechanism of the ceramic TiO2-xNx spherical powder induced by annealing in air

Camagu, S.T.; Bolokang, A.S.; Muller, T.F.G.; Motaung, David E.; Arendse, Christopher J.

doi:10.1016/j.powtec.2019.04.030

Cited by 9 publications

(4 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to Equation (2), the lower surface tension under a nitrogen atmosphere leads to a lower dynamic viscosity than that under an argon atmosphere. Additionally, a higher nitrogen content in the sample built under nitrogen (Table 1) would change the surface from triangular grains to irregular-shaped grains [43]. Therefore, the surface morphology of the specimens processed under nitrogen was smoother than that of those processed under argon.…”

Section: Discussionmentioning

confidence: 99%

Effect of atmosphere on the microstructure and properties of additively manufactured tungsten

Dong

Liu

Chen

et al. 2020

Materials Science and Technology

View full text Add to dashboard Cite

The working atmosphere greatly affects the melting and solidification processes in powder-based additive manufacturing. In this work, pure tungsten components were fabricated by selective laser melting (SLM) under argon and nitrogen, respectively. The effects of the atmosphere and processing parameters on densiﬁcation, microstructures, and phases were investigated. Tungsten processed under nitrogen exhibited a higher density, lower roughness, and superior mechanical performance than that processed under argon. The high dynamic viscosity of liquid tungsten in argon induced balling and pore formation during the laser melting process, leading to relatively low density and poor mechanical properties of the SLM-processed tungsten that was manufactured in argon. The results help to promote the practical application of SLM for complicated tungsten components in the nuclear and military industries.

show abstract

Section: Discussionmentioning

confidence: 99%

Effect of atmosphere on the microstructure and properties of additively manufactured tungsten

Dong

Liu

Chen

et al. 2020

Materials Science and Technology

View full text Add to dashboard Cite

show abstract

“…Comparing to the XRD results, XPS analysis not only confirmed the existence of the main phases, but also detected some trace bonds that were conducive to reveal the solid solution behavior of N and O elements. 14,33…”

Section: Xps Analysismentioning

confidence: 99%

Synthesis of vanadium nitride from vanadium spinel by synchronous reduction and nitridation with ammonia energy

You

et al. 2022

Intl J of Energy Research

View full text Add to dashboard Cite

Summary Ammonia gas (NH3) is a clean energy, as well as an efficient reduction and nitridation agent. A novel process of reduction and nitridation with NH3 followed by magnetic separation and low‐temperature selective chlorination to deal with vanadium slag has been proposed. Vanadium spinel (V‐Fe spinel, FeV2O4) is the main V‐bearing phase in vanadium slag, and its reduction and nitridation behavior with NH3 were investigated in this study. Thermodynamic analysis indicated that the reaction was feasible. The experimental results demonstrated that NH3 gas was an excellent reagent for reduction and nitridation. DFT calculation proved that NH3 molecule was easier adsorbed on V atom. The phase component of the final product was Fe/Fe4N/VNxOy, whose relative mass fractions obtained by Rietveld refinement analysis were 23.5%, 1%, and 75.5%, respectively. The evolution of iron and vanadium was in the order FeV2O4 → Fe4N/Fe6N2−3 → Fe4N/Fe and FeV2O4 → V2O3 → VNxOy, respectively. VNxOy was a solid solution, whose O content decreased gradually as the temperature and duration time increased, whereas the N content increased correspondingly. The O content can be decreased to less than 0.10 wt.% after reduction and nitridation at 800°C to 850°C for 3 h.

show abstract

“…These features are inherited in a pure Ti with a hexagonal close packed (HCP) structure, which transforms upon heating above 882 • C and changes to body-centred cubic (BCC) structure. When cooled down to room temperature, this metal remembers its ground state HCP crystal structure; and this phenomenon called the (α↔β) reversible phase transformation [6,7]. This α↔β phase transition temperature can be altered by impurities, alloying as well as deformations processes [7,8].…”

Section: Introductionmentioning

confidence: 99%

Grain structure orientational change in Ti6Al4V alloys induced by sea water quenching and novel stress relief annealing process

Bolokang

Mathabathe

Motaung

et al. 2023

Materials Chemistry and Physics

View full text Add to dashboard Cite

Surface characterization and formation mechanism of the ceramic TiO2-xNx spherical powder induced by annealing in air

Cited by 9 publications

References 43 publications

Effect of atmosphere on the microstructure and properties of additively manufactured tungsten

Effect of atmosphere on the microstructure and properties of additively manufactured tungsten

Synthesis of vanadium nitride from vanadium spinel by synchronous reduction and nitridation with ammonia energy

Grain structure orientational change in Ti6Al4V alloys induced by sea water quenching and novel stress relief annealing process

Contact Info

Product

Resources

About