Processing, Microstructures and Properties of a Ti-6Al-4V Extrusion Produced by an Industrial Scale Setup

2018 ◽  
Vol 770 ◽  
pp. 60-69
Author(s):  
Ajit Pal Singh ◽  
Fei Yang ◽  
Rob Torrens ◽  
Brian Gabbitas ◽  
Barry Robinson ◽  
...  
Keyword(s):  
Oxygen Content ◽  
Industrial Scale ◽  
Vacuum Sintering ◽  
High Oxygen Content ◽  
Blended Powder ◽  
Micro Cracks ◽  
Processed Material ◽  
Compositional Homogeneity ◽  
Mechanical Performances ◽  
Oxygen Pickup

In this paper, a Ti-6Al-4V rectangular bar was successfully produced from a 5kg blended powder mixture using an industrial scale extrusion facility. The elemental hydride-dehydride (HDH) titanium and 60Al-40V master alloy mixture was warm pressed and vacuum sintered prior to β extrusion in air. The as-processed material was characterised for compositional homogeneity, oxygen pickup, microstructure, tensile properties and fracture behavior. Variation in microstructure and properties along the length of the extruded bar were also studied. It was found that oxygen pickup mainly occurred during vacuum sintering of the green billet and consequently the as-extruded material had an oxygen content of 0.55 wt.%. The processed material had a typical lamellar morphology with some evidence of micro-cracks at high magnification. A significant deviation in prior β grain and α colony sizes was observed along the length of the bar, due to variations in extrusion temperature and cooling rate. Both grains and colonies became finer as the location changed from the tip of the extruded bar to the back end. The as-processed material had ultimate tensile strength in the range of 1068-1268 MPa and elongation to fracture of 1.2-4.5%, mainly due to the high oxygen content and non-optimised microstructure. Fractographic analysis was consistent with the variation in mechanical performances obtained.

scholarly journals Heat Treatment, Impact Properties, and Fracture Behaviour of Ti-6Al-4V Alloy Produced by Powder Compact Extrusion

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3824 ◽  
Author(s):  
Singh ◽  
Yang ◽  
Torrens ◽  
Gabbitas
Keyword(s):  
Impact Toughness ◽  
Powder Compact ◽  
Fracture Behaviour ◽  
Hot Extrusion ◽  
Impact Testing ◽  
Vacuum Sintering ◽  
Blended Powder ◽  
Heat Treated ◽  
Processed Material ◽  
The Impact

The mechanical properties of titanium and titanium alloys are very sensitive to processing, microstructure, and impurity levels. In this paper, a blended powder mixture of Ti-6Al-4V alloy was consolidated by powder compact extrusion that involved warm compaction, vacuum sintering, and hot extrusion. The as-processed material with an oxygen content of 0.34 wt.% was subjected to various annealing treatments. The impact toughness of heat-treated material was determined using Charpy V-notch impact testing at room temperature. An emphasis was placed on establishing a relationship among fracture behaviour, microstructure, and the resulting properties of tested material. From the results, it is apparent that the highest impact toughness value of 19.3 J was achieved after α/β annealing and is comparable with typical values given in the literature for wrought Ti-6Al-4V. In terms of fracture behaviour, it is quite apparent that the crack propagation behaviour of powder-produced material is rather complex compared with the limited amount of data reported for ingot counterparts.

Annealing of defects in irradiated silicon detector materials with high oxygen content

2005 ◽  
Vol 17 (22) ◽  
pp. S2247-S2253 ◽  
Author(s):  
M Mikelsen ◽  
E V Monakhov ◽  
G Alfieri ◽  
B S Avset ◽  
J Härkönen ◽  
...  
Keyword(s):  
Oxygen Content ◽  
Silicon Detector ◽  
High Oxygen ◽  
High Oxygen Content ◽  
Detector Materials

scholarly journals Research on microstructure and properties of Ti-15Mo-3Al alloy with high oxygen content

2020 ◽  
Vol 7 (11) ◽  
pp. 116528
Author(s):  
Zaidong Xu ◽  
Yanjing Wang ◽  
Rongzheng Xu ◽  
Qiuye Hu ◽  
Dongyu Shi ◽  
...  
Keyword(s):  
Oxygen Content ◽  
High Oxygen ◽  
High Oxygen Content ◽  
Microstructure And Properties

scholarly journals Development of α+β-type biomedical Ti–Nb alloys with high oxygen content

2020 ◽  
Vol 321 ◽  
pp. 05003
Author(s):  
K. Ueda ◽  
M. Omiya ◽  
Y. Hirose ◽  
T. Narushima
Keyword(s):  
Oxygen Content ◽  
Low Cost ◽  
Total Elongation ◽  
Ti Alloy ◽  
High Oxygen Content ◽  
Β Phase ◽  
Α Phase ◽  
Heat Treated ◽  
Iced Water ◽  
Nb Content

Ti-(5–20)Nb-(0.5–1)O alloys (mass%) were investigated for developing low-cost biomedical α+β-type Ti alloy. Ti-(5, 10, 15, 20)Nb-(0.5, 0.75, 1)O alloys (mass%) were arc-melted and forged into bars. The forged alloy bars were heat-treated at 873 to 1373 K for 3.6 ks in an Ar atmosphere and quenched in iced water. β transus (Tβ) of the Ti-Nb-O alloys decreased with increasing Nb content. An increase in the oxygen content led to an increase in Tβ. After quenching, the formation of α′ martensite was observed in Ti-5Nb-yO alloys. An increase in the Nb content to 10 mass% led to the formation of α′ and α″ martensites. A further increase in the Nb content to 15 and 20mass% resulted in the formation of more α″ martensites. The boundary temperature for the formation of α′ and α″ martensite in the Ti-10Nb-yO alloys increased with increasing oxygen content, because oxygen enhances the Nb distribution to the β phase. The ultimate tensile strength of the Ti-xNb-0.75O alloys heattreated to obtain the α-phase fraction (fα) of 0.5 was over 1000 MPa, except for the Ti-15Nb-0.75O alloy. The total elongation decreased with increasing Nb content. The Ti-5Nb-0.75O alloy exhibited excellent strength-ductility balance as a low-cost α+β-type biomedical Ti alloy.

Nanometer size effect on the structure and magnetic properties of high oxygen content ferromagnetic PrMnO3+δ nanoparticles

2010 ◽  
Vol 108 (11) ◽  
pp. 113901 ◽  
Author(s):  
T. Zhang ◽  
Y. Z. Fang ◽  
M. Dressel ◽  
X. P. Wang ◽  
Q. F. Fang
Keyword(s):  
Magnetic Properties ◽  
Size Effect ◽  
Oxygen Content ◽  
High Oxygen ◽  
High Oxygen Content ◽  
Nanometer Size

High-Oxygen-Content Carbon Dots as a High-Efficiency Inhibitor of Human Insulin Aggregation

2019 ◽  
Vol 2 (9) ◽  
pp. 4067-4076 ◽  
Author(s):  
Chen-Qiao Li ◽  
Xing-Yu Liu ◽  
Shu-Lan Li ◽  
Peng Jiang ◽  
Feng-Lei Jiang ◽  
...  
Keyword(s):  
Oxygen Content ◽  
Human Insulin ◽  
Carbon Dots ◽  
High Efficiency ◽  
High Oxygen ◽  
High Oxygen Content

scholarly journals Mechanism of HCB-Modified Asphalt and Dynamic Properties of Mixtures

2020 ◽  
Vol 10 (14) ◽  
pp. 4971
Author(s):  
Zhan Ding ◽  
Jinfei Su ◽  
Peilong Li ◽  
Hui Bing
Keyword(s):  
Functional Groups ◽  
Oxygen Content ◽  
Performance Test ◽  
Dynamic Properties ◽  
Chemical Properties ◽  
Active Surface ◽  
Asphalt Mixtures ◽  
Low Frequencies ◽  
High Oxygen Content ◽  
Modified Asphalt

Hydroxymethyl carbon black (HCB) was prepared as an asphalt modifier with a high oxygen content and active surface chemical properties. The microstructure of HCB was analyzed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy. The improvement effect of HCB on asphalt’s physical, dynamic shear, rheological, and aging properties was evaluated. To analyze the dynamic properties of the HCB-modified asphalt mixtures, a simple performance test (SPT) was conducted, and then the change laws of the dynamic modulus and phase angle for the HCB mixtures were clarified. The results showed that the surface of HCB is smooth and that the oxygen content increases with the generation of hydroxyl functional groups. Polar oxygen-containing functional groups and hydrogen bonds are helpful in improving the resistance to cracking and aging. The surface activity of HCB is susceptible to temperature and frequency, causing a slight influence of HCB on the viscoelasticity of asphalt mixtures at high and low frequencies. At low temperatures and high frequencies, the HCB enhanced the elasticity characteristics and weakened the viscosity characteristics of asphalt mixtures.

Combustion system optimization for dimethyl ether using a genetic algorithm

2019 ◽  
Vol 22 (1) ◽  
pp. 22-38 ◽  
Author(s):  
Marius Zubel ◽  
Tamara Ottenwälder ◽  
Benedikt Heuser ◽  
Stefan Pischinger
Keyword(s):  
Oxygen Content ◽  
Dimethyl Ether ◽  
Ignition Delay ◽  
System Optimization ◽  
High Oxygen ◽  
Experimental Investigations ◽  
Compression Ignition Engine ◽  
High Oxygen Content ◽  
Volumetric Heating ◽  
Cooling Effects

Dimethyl ether is a gaseous fuel which can easily be liquefied under moderate pressures. Its high reactivity makes it suitable for combustion in a compression ignition engine, and due to the high oxygen content, its combustion is virtually free of soot. The high oxygen content and low density of dimethyl ether lead to a lower volumetric heating value compared to Diesel fuel. Therefore, the hydraulic flow rates of the injectors have to be increased with larger nozzle holes. The influence of larger nozzle holes on the dimethyl ether spray formation and ignition are presented in this article. Experimental investigations were conducted at a constant-pressure vessel with optical access and with a single-cylinder research engine. Subsequently, a numerical optimization of the piston bowl and injector nozzle has been carried out. A very fast air/fuel mixture formation with dimethyl ether was observed, which leads to a lean combustion with small nozzle diameters. With increasing nozzle diameters, the combustion moves toward stoichiometric conditions and with very large diameters to rich combustion conditions. The ignition delay for small diameters is mostly dominated by the lean mixture, and for large diameters, the ignition delay is strongly influenced by cooling effects. For the optimization, the oxidation potential number was maximized, which proved suitable to simultaneously increase efficiency and reduce emissions. A conventional ω-shaped bowl and a step bowl have been optimized, and large bowl diameters were found to be beneficial for dimethyl ether combustion. Furthermore, nozzle diameters around 150 µm showed the most promising results. Compared to the dimethyl ether reference, the simulations with the optimized ω-shaped bowl showed a power increase of 2.7%. Experimentally, the optimized ω-shaped bowl in combination with the reference injector showed an efficiency increase by more than 1% at 2000 r/min full load compared to the dimethyl ether reference.

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