scholarly journals Deoxygenation of liquid titanium with aluminum addition

2020 ◽  
Vol 321 ◽  
pp. 10002
Author(s):  
Daisuke Matsuwaka ◽  
Fumiaki Kudo ◽  
Hitoshi Ishida ◽  
Tetsushi Deura
Keyword(s):  
Oxygen Content ◽  
Aluminum Content ◽  
Emission Spectrometry ◽  
Oxygen Solubility ◽  
Low Oxygen ◽  
Arc Melting ◽  
Liquid Titanium ◽  
Metal Flux ◽  
Induction Skull Melting ◽  
Quality Material

To realize radical cost reduction of titanium, a process is needed which can directly make use of low quality material such as scrap, TiO2 or titanium ore. In this work, a highly efficient process has been developed to produce low oxygen titanium alloy using aluminum to rapidly reduce oxygen during melting. In this experiment titanium was prepared including 0.8 mass% oxygen. This titanium and aluminum in the range of 0 – 60 mass% was measured, mixed and melted by PAM (plasma arc melting) or ISM (induction skull melting). After melting, a small piece was taken and the aluminum and oxygen content was analyzed by ICP emission spectrometry and inert gas fusion-infrared absorption method respectively. A sample melted with CaO-CaF2 flux was analyzed as well after flux was mechanically taken off. As aluminum content increased, oxygen content decreased. For example, when 61.9 mass% aluminum was added, the oxygen content decreased to 0.028 mass% and Al2O3 was observed in the cross-section of the sample after melting. This was produced when the aluminum content increased and the oxygen solubility decreased in the metal. Flux addition was also clearly effective for deoxygenation.

Carbon and the Kinetics of Oxygen Precipitation in Silicon

1982 ◽  
Vol 14 ◽  
Author(s):  
R.F. Pinizzotto ◽  
S. Marks
Keyword(s):  
Oxygen Content ◽  
Oxygen Concentration ◽  
Carbon Concentration ◽  
Oxygen Solubility ◽  
Low Oxygen ◽  
Subsequent Increase ◽  
High Oxygen Content ◽  
Oxygen Precipitation ◽  
Precipitate Growth ◽  
Initial Oxygen

ABSTRACTOxygen precipitation in Czochralski silicon has been studied as a function of anneal time, oxygen concentration and carbon concentration using FTIR. It was found that the oxygen supersaturation controls the precipitation kinetics in high oxygen content samples, whereas the carbon concentration is of prime importance in low oxygen content samples. The decrease in sustitutional carbon concentration after nucleation and its subsequent increase with extended growth anneals supports the view that carbon affects precipitate nucleation, but not precipitate growth. The measured oxygen solubility at 1000°C was found to depend on both the initial oxygen concentration and the initial carbon concentration.

scholarly journals Effect of Zr Purity and Oxygen Content on the Structure and Mechanical Properties of Melt-Spun and Suction-Cast Cu46Zr42Al7Y5 Alloy

2016 ◽  
Vol 61 (2) ◽  
pp. 1215-1219 ◽  
Author(s):  
T. Kozieł ◽  
J. Latuch ◽  
G. Cios ◽  
P. Bała
Keyword(s):  
Mechanical Properties ◽  
Oxygen Content ◽  
Melt Spinning ◽  
Amorphous Structure ◽  
High Oxygen ◽  
Low Oxygen ◽  
Scanning Calorimetry ◽  
Dsc Studies ◽  
Arc Melting ◽  
Melt Spun

AbstractThe effect of oxygen content in zirconium on the structure and mechanical properties of the Cu46Zr42Al7Y5alloy, in the form of melt-spun ribbons and suction-cast rods, was investigated. Two types of Zr, rod and crystal bar of different nominal purities and oxygen contents, were used to synthesize the alloy by arc melting. Rapidly solidified ribbons were produced by melt spinning and their amorphous structures were confirmed by X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). Bulk samples in the form of rods were cast using a special water-cooled suction casting unit attached to the arc melting system. XRD and DSC studies proved the amorphous structure of the bulk alloy synthesized from low-oxygen Zr and partial crystallization of the same alloy for high-oxygen Zr. In both bulk samples, uniformly distributed crystalline particles were identified as yttrium oxides. Higher mean compressive strength of amorphous alloy was observed. The hardness of amorphous phase was close to 500 HV1 in both bulk alloys, while the hardness of crystalline dendritic areas, observed in the alloy synthesized from high oxygen Zr, was lower by about 50 HV1.

Effect of the Sintering Atmosphere on the Corrosion Resistance of Titanium for Application as Biomaterial

2012 ◽  
Vol 727-728 ◽  
pp. 85-89
Author(s):  
Luzinete P. Barbosa ◽  
Elki C. Souza ◽  
Lucio Salgado ◽  
I. Costa
Keyword(s):  
Corrosion Resistance ◽  
Oxygen Content ◽  
Passive Film ◽  
Titanium Surface ◽  
Sintered Titanium ◽  
Nacl Solution ◽  
Low Oxygen ◽  
Sintering Atmosphere ◽  
Corrosion Tests ◽  
Vacuum Atmosphere

In this work, the effect of sintering atmosphere on the corrosion resistance of sintered titanium has been evaluated in 0.9 % aqueous NaCl solution to simulate physiological environment. Corrosion tests were performed on titanium porous sintered under vacuum and vacuum plus dynamic argon. The results showed better passive properties associated to the titanium sintered under argon plus vacuum atmosphere than to the vacuum sintered titanium. The better corrosion resistance of the argon plus vacuum sintered titanium was attributed to the formation of a thin passive film on the titanium surface during sintering due the low oxygen content present in this atmosphere.

scholarly journals THE MORPHOLOGICAL CHANGES IN THE TISSUES OF THE RABBIT AS A RESULT OF REDUCED OXIDATION

1918 ◽  
Vol 27 (3) ◽  
pp. 399-412 ◽  
Author(s):  
H. G. Martin ◽  
A. S. Loevenhart ◽  
C. H. Bunting
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Content ◽  
Morphological Changes ◽  
Low Oxygen ◽  
High Carbon ◽  
Red Bone Marrow ◽  
Hydropic Degeneration ◽  
Thyroid Hyperplasia ◽  
High Carbon Dioxide ◽  
Stimulation Of

Exposure of rabbits to an atmosphere of low oxygen content results in a stimulation of the cardiorespiratory systems, in an extension (hyperplasia) of red bone marrow and probably of a thyroid hyperplasia, with the further production of hydropic and hyaline degeneration in the cells of the parenchymatous organs. An atmosphere of high carbon dioxide and normal oxygen content produces, however, a stimulation of the cardiorespiratory systems, but no marrow extension and, in the concentrations used, but slight hydropic degeneration in the parenchyma of the glandular organs.

scholarly journals The Function of the Gills of Mayfly Nymphs from Different Habitats

1939 ◽  
Vol 16 (3) ◽  
pp. 363-373 ◽  
Author(s):  
C. A. WINGFIELD
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Content ◽  
The Body ◽  
Gaseous Exchange ◽  
Low Oxygen ◽  
Respiratory Mechanism ◽  
Tracheal Gills ◽  
Cloeon Dipterum ◽  
Gill Function ◽  
Oxygen Concentrations

1. The oxygen consumption of normal and gill-less nymphs of the mayflies Baetis sp., Cloeon dipterum and Ephemera vulgata has been measured at various oxygen concentrations. 2. It has been found that over the complete range of oxygen concentrations studied, the tracheal gills do not aid oxygen consumption in Baetis sp. In Cloeon dipterum, at all oxygen concentrations tested, no gaseous exchange takes place through the gills; at low oxygen concentrations, however, the gills function as an accessory respiratory mechanism in ventilating the respiratory surface of the body and so aid oxygen consumption. In Ephemera Vulgata the gills aid oxygen consumption even at high oxygen concentrations. In this species the gills may function both as true respiratory organs and as a ventilating mechanism. 3. It is shown that the differences in gill function can be related to the oxygen content of the habitat of each species.

Properties and CA4GE-Engine Test of TiAl-Based Alloy Valves by Permanent Mold Casting

2010 ◽  
Vol 139-141 ◽  
pp. 557-560
Author(s):  
Wen Bin Sheng ◽  
Chun Xue Ma ◽  
Wan Li Gu
Keyword(s):  
Tial Alloy ◽  
Centrifugal Casting ◽  
Casting Process ◽  
Vacuum Arc ◽  
Permanent Mold ◽  
Casting Method ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Mold Casting ◽  
Induction Skull Melting

TiAl-based alloy valves were manufactured by combining charges compressed /vacuum arc melting (VA)/ induction skull melting (ISM) procedure with permanent mold centrifugal casting method. Microstructures, compositions and mechanical properties of as-cast and hot isostatical pressed (HIPed) valves are detected. Results show that the permanent mold centrifugal casting process obviously refines the size of grain in TiAl alloy and the tensile strength of as-cast and HIPed valves are 550MPa and 580MPa at 20°C, 370MPa and 470MPa at 815°C, respectively. As-cast specimens show ~0% elongation at 20°C and 1~2% at 815°C, while HIPed ones show an elongation of 1~2% at room temperature and about 10% at 815°C. Furthermore, a 200-hour test was carried out with CA4GE-engine, which demonstrated the possibility of as-cast TiAl alloy valves for the substitution of present steel ones.

Thermodynamic Characteristics of Y2O3 and Y2S3 Nonmetallic Phase Formed in Liquid Steel

2020 ◽  
Vol 844 ◽  
pp. 9-23
Author(s):  
Sergii Gerasin ◽  
Dorota Kalisz ◽  
Jerzy Iwanciw
Keyword(s):  
Oxygen Content ◽  
Molten Steel ◽  
Liquid Steel ◽  
Thermodynamic Characteristics ◽  
Phase Precipitation ◽  
Low Oxygen ◽  
Metallic Oxide ◽  
Metal Bath ◽  
Metallic Inclusions ◽  
The Relationship

The current work deals the phenomenon of non-metallic inclusions as a result of the addition of Yttrium as an alloying component. The order of introducing individual components determines its final content in steel. This problem was analyzed using the WYK_Stal program developed at AGH-UST. Individual cases were considered using the accepted thermodynamics models based on Wagner’s formalism. The study of Y2O3 and Y2S3 phase precipitation and the relationship between the addition of Y, Al, Ca, O and S in molten steel was studied using the thermodynamic models. Based on the simulation, the authors stated that, the introduction of aluminum as the final deoxidizer into the liquid steel before the yttrium, results in the formation of non-metallic oxide inclusions. The low oxygen content in the metal bath promotes the formation of yttrium sulphide. In the case of calcium dosing, it is reasonable that, the yttrium is introduced after this element, which limits the losses on the formation of the yttrium sulphide phase.

scholarly journals Graphene Oxide Oxygen Content Affects Physical and Biological Properties of Scaffolds Based on Chitosan/Graphene Oxide Conjugates

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1142 ◽  
Author(s):  
Iolanda Francolini ◽  
Elena Perugini ◽  
Ilaria Silvestro ◽  
Mariangela Lopreiato ◽  
Anna Scotto d’Abusco ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Mechanical Strength ◽  
Oxygen Content ◽  
Mechanical Stability ◽  
Biological Properties ◽  
Dermal Fibroblasts ◽  
Porous Scaffolds ◽  
Low Oxygen ◽  
Interdisciplinary Field

Tissue engineering is a highly interdisciplinary field of medicine aiming at regenerating damaged tissues by combining cells with porous scaffolds materials. Scaffolds are templates for tissue regeneration and should ensure suitable cell adhesion and mechanical stability throughout the application period. Chitosan (CS) is a biocompatible polymer highly investigated for scaffold preparation but suffers from poor mechanical strength. In this study, graphene oxide (GO) was conjugated to chitosan at two weight ratios 0.3% and 1%, and the resulting conjugates were used to prepare composite scaffolds with improved mechanical strength. To study the effect of GO oxidation degree on scaffold mechanical and biological properties, GO samples at two different oxygen contents were employed. The obtained GO/CS scaffolds were highly porous and showed good swelling in water, though to a lesser extent than pure CS scaffold. In contrast, GO increased scaffold thermal stability and mechanical strength with respect to pure CS, especially when the GO at low oxygen content was used. The scaffold in vitro cytocompatibility using human primary dermal fibroblasts was also affected by the type of used GO. Specifically, the GO with less content of oxygen provided the scaffold with the best biocompatibility.

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