scholarly journals The Effect of Oxygen Content in Binderless Cokes for High-Density Carbon Blocks from Coal Tar Pitch

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1832
Author(s):  
Seungjoo Park ◽  
Seon Ho Lee ◽  
Song Mi Lee ◽  
Jin-Woo Park ◽  
Sung-Soo Kim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Oxygen Content ◽  
Flow Rate ◽  
Coal Tar ◽  
High Density ◽  
Coal Tar Pitch ◽  
Air Flow Rate ◽  
Carbon Block ◽  
Effect Of Oxygen

High-density carbon blocks are much lighter than metals and have excellent mechanical properties and are one of the materials garnering attention to replace existing metal parts. In this study, a binderless coke was produced by changing the flow rates of nitrogen and air as a carrier gas during heat treatment of coal tar pitch and using this, a green body was formed at 150 MPa and carbonized to produce a high-density carbon block. We express the binderless coke produced in this way by N10A0, N7A3, N5A5, N3A7, N0A10 according to the ratio of nitrogen and air, and in the case of carbon block, we have added CB in front of it. We then considered the effect of oxygen content in the binderless cokes on the optical, chemical, and mechanical properties. It was observed that the produced binderless cokes develop into a dense mosaic structure with a small particle size as the air flow rate increased. To survey the change in oxygen content of the produced binderless coke, O1s and C1s regions were measured using X-ray photoelectric spectroscopy (XPS), and O1s/C1s was calculated. The O1s/C1s ratio steadily increased as the air flow rate increased, and in the case of N0A10, it increased about twice as much as that of N10A0 to 11.20%. β-resin has a very large effect on the mechanical strength of the carbon block in addition to air in the pitch. And in the case of CB-N0A10, it shows the best mechanical strength with a density of 1.72 g/cm3, bending strength of 87 MPa, and shore hardness of 93 HSD.

Preparation of High Density Graphite Materials from Coal Tar Pitch

1994 ◽  
Vol 349 ◽  
Author(s):  
Yang-Duk Park ◽  
Chul-Woo Kim ◽  
Young-Dae Seo
Keyword(s):  
Mechanical Properties ◽  
Coal Tar ◽  
Resin Content ◽  
High Density ◽  
Coal Tar Pitch ◽  
Wet Milling ◽  
Density Graphite ◽  
Milling Method

ABSTRACTPreparation of high density graphite materials from coal tar pitch was investigated. The effect of β-resin content on the mechanical properties of graphite solid prepared from semi-coke, which was prepared by wet milling method, was examined. β-Resin content was effective for fabrication of green bodies without lamination and for improving the mechanical properties of graphite materials.

Mechanical Properties of Single-Melt PAM Processed Ti-6Al-4V Forgings

2013 ◽  
Vol 551 ◽  
pp. 186-209 ◽  
Author(s):  
Mustafa Guclu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Oxygen Content ◽  
Low Cost ◽  
Vacuum Arc ◽  
Fatigue And Fracture ◽  
Microstructure Examination ◽  
Toughness Testing ◽  
Alpha Beta ◽  
Effect Of Oxygen

Ti-6Al-4V pancakes were manufactured by alpha-beta forging using single-melt (SM) plasma arc melt (PAM) billet stock at three oxygen levels, 0.16, 0.20 and 0.24 wt%, along with a standard double vacuum arc remelted (2XVAR) billet stock at 0.17 wt% oxygen for baseline comparison. Mechanical properties of forgings in the mill-, recrystallization- and beta-annealed conditions were then characterized by microstructure examination, tensile, smooth bar axial fatigue and fracture toughness testing in radial orientation. The effect of oxygen content on mechanical properties of the forgings was assessed. All SM PAM forgings exhibited slightly higher tensile and fatigue strength compared to those of 2XVAR. The fracture toughness values decreased with increasing oxygen content. Microstructures of all forgings were similar to those of conventional alpha-beta forgings. The data presented in this paper can be useful to designers in their efforts to introduce low-cost SM PAM Ti-6Al-4V (Ti-6-4) alloy forgings into various U.S. defense applications.

scholarly journals Influence of Oxygen on the Fatigue Behaviour of Ti-6Al-7Nb Alloy

2016 ◽  
Vol 704 ◽  
pp. 44-52 ◽  
Author(s):  
Alexandra Amherd Hidalgo ◽  
Thomas Ebel ◽  
Wolfgang Limberg ◽  
Florian Pyczak
Keyword(s):  
Mechanical Properties ◽  
Oxygen Content ◽  
Treatment Time ◽  
Light And Electron Microscopy ◽  
Tensile Tests ◽  
Fatigue Behaviour ◽  
Fatigue Tests ◽  
Four Point Bending ◽  
Initiation And Propagation ◽  
Effect Of Oxygen

One of the challenges in PM Ti alloys is to control the impurities level. Oxygen affects the microstructure and the mechanical properties of titanium alloys. Ti-6Al-7Nb is a promising alloy to use in PM due to its outstanding biocompatibility and mechanical properties required for load bearing medical implants. In this work, the influence of the impurities content on the ductility, fatigue resistance and microstructure of Ti-6Al-7Nb alloy processed by metal injection moulding was examined. Tensile and fatigue specimens were manufactured using Ti-6Al-7Nb gas atomized powder. Depending on the thermal treatment time, various oxygen contents were introduced into the specimens. The resulting oxygen content was determined by melt extraction technique. Tensile tests and high cycle four-point bending fatigue tests at room temperature were performed. First studies about the effect of oxygen content on crack initiation and propagation were done by the observation of microstructures and fractured surfaces using light and electron microscopy (SEM).

Effect of Oxygen Content in Powders on Microstructure and Mechanical Properties of WC-FeAl Composites Fabricated by Vacuum Sintering Technique

2015 ◽  
Vol 1088 ◽  
pp. 115-119 ◽  
Author(s):  
Ryoichi Furushima ◽  
Kiyotaka Katou ◽  
Koji Shimojima ◽  
Hiroyuki Hosokawa ◽  
Akihiro Matsumoto
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Oxygen Content ◽  
Rupture Strength ◽  
Powder Preparation ◽  
Vacuum Sintering ◽  
Transverse Rupture Strength ◽  
Sintered Composite ◽  
Lower Oxygen ◽  
Effect Of Oxygen

WC-FeAl composites were fabricated by vacuum sintering technique from mixture of WC and FeAl powders containing various oxygen content. Mechanical properties such as hardness, fracture toughness and transverse rupture strength were influenced by the oxygen content in the powders. Control of the oxygen content was succeeded by changing the powder preparation process. Contrary to expectations, the reduction of oxygen content led to degrade the fracture toughness and transverse rupture strength of the composites. This result was attributed to the microstructural change in the sintered composite. The sintered composite of lower oxygen content exhibited WC grain growth or inhomogeneous microstructure, which can be the cause of degradation of those mechanical properties. It was concluded that the oxygen content was one of the key factors to influence the microstructure or mechanical properties of WC-FeAl composites.

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