scholarly journals Prediction of microstructure evolution during hot gas forming of Ti2AlNb-based alloy tubular component with square cross-section

2018 ◽  
Vol 15 ◽  
pp. 1156-1163 ◽  
Author(s):  
Zhiqiang Liu ◽  
Xiaosong Wang ◽  
Xueyan Jiao ◽  
Yong Wu ◽  
Gang Liu
Keyword(s):  
Cross Section ◽  
Microstructure Evolution ◽  
Hot Gas ◽  
Hot Gas Forming ◽  
Tubular Component

scholarly journals Investigation on precision and performance for hot gas forming of thin-walled components of Ti2AlNb-based alloy

2018 ◽  
Vol 190 ◽  
pp. 07001
Author(s):  
Xueyan Jiao ◽  
Zhiqiang Liu ◽  
Yong Wu ◽  
Gang Liu
Keyword(s):  
Process Parameters ◽  
Microstructure Evolution ◽  
Element Model ◽  
Parameters Optimization ◽  
Forming Process ◽  
Performance Control ◽  
Hot Gas ◽  
Thin Walled ◽  
And Performance ◽  
Hot Gas Forming

Ti2AlNb-based alloys have received considerable attention as potential materials to replace the nickel alloy at 600-750 °C, depending on their advantages of high specific strength, good corrosion and oxidation resistance. To realize the precision and performance control for Ti2AlNb-based alloy thin-walled components, the microstructure evolution was analyzed for setting up the unified viscoplastic constitutive equations based on the physical variables and simulating the forming process coupled between the deformation and the microstructure evolution. Through the finite element model with coupling of microstructure and mechanical parameters, the microstructure evolution and shape fabricating can be predicted at the same time, to provide the basis for the process parameters optimization and performance control. With the reasonable process parameters for hot gas forming of Ti2AlNb thin-walled components, the forming precision and performance can be controlled effectively.

Formability and microstructure evolution for hot gas forming of laser-welded TA15 titanium alloy tubes

2016 ◽  
Vol 91 ◽  
pp. 269-277 ◽  
Author(s):  
Kehuan Wang ◽  
Gang Liu ◽  
Jie Zhao ◽  
Jianlong Wang ◽  
Shijian Yuan
Keyword(s):  
Titanium Alloy ◽  
Microstructure Evolution ◽  
Hot Gas ◽  
Ta15 Titanium Alloy ◽  
Hot Gas Forming

scholarly journals Ultraviolet Absorption Cross-Sections of Ammonia at Elevated Temperatures for Nonintrusive Quantitative Detection in Combustion Environments

2021 ◽  
pp. 000370282199044
Author(s):  
Wubin Weng ◽  
Shen Li ◽  
Marcus Aldén ◽  
Zhongshan Li
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Absorption Cross Section ◽  
Elevated Temperatures ◽  
Uv Absorption ◽  
Energy Utilization ◽  
Quantitative Detection ◽  
Absorption Cross ◽  
Hot Gas

Ammonia (NH3) is regarded as an important nitrogen oxides (NOx) precursor and also as an effective reductant for NOx removal in energy utilization through combustion, and it has recently become an attractive non-carbon alternative fuel. To have a better understanding of thermochemical properties of NH3, accurate in situ detection of NH3 in high temperature environments is desirable. Ultraviolet (UV) absorption spectroscopy is a feasible technique. To achieve quantitative measurements, spectrally resolved UV absorption cross-sections of NH3 in hot gas environments at different temperatures from 295 K to 590 K were experimentally measured for the first time. Based on the experimental results, vibrational constants of NH3 were determined and used for the calculation of the absorption cross-section of NH3 at high temperatures above 590 K using the PGOPHER software. The investigated UV spectra covered the range of wavelengths from 190 nm to 230 nm, where spectral structures of the [Formula: see text] transition of NH3 in the umbrella bending mode, v2, were recognized. The absorption cross-section was found to decrease at higher temperatures. For example, the absorption cross-section peak of the (6, 0) vibrational band of NH3 decreases from ∼2 × 10−17 to ∼0.5 × 10−17 cm2/molecule with the increase of temperature from 295 K to 1570 K. Using the obtained absorption cross-section, in situ nonintrusive quantification of NH3 in different hot gas environments was achieved with a detection limit varying from below 10 parts per million (ppm) to around 200 ppm as temperature increased from 295 K to 1570 K. The quantitative measurement was applied to an experimental investigation of NH3 combustion process. The concentrations of NH3 and nitric oxide (NO) in the post flame zone of NH3–methane (CH4)–air premixed flames at different equivalence ratios were measured.

Microstructure Evolution of Epitaxial (Ba, Sr) TiO3/ (001) HgO Thin Films

1994 ◽  
Vol 361 ◽  
Author(s):  
V.A. Alyoshin ◽  
E.V. Sviridov ◽  
V.I.M. Hukhortov ◽  
I.H. Zakharchenko ◽  
V.P. Dudkevich
Keyword(s):  
Thin Films ◽  
Cross Section ◽  
Microstructure Evolution ◽  
Three Dimensional ◽  
Gas Pressure ◽  
Smooth Surfaces ◽  
Two Dimensional ◽  
Surface Versus ◽  
Deposition Conditions

ABSTRACTSurface and cross-section relief evolution of ferroelectric epitaxial (Ba,Sr)TiO3 films rf-sputtered on (001) HgO crystal cle-avage surface versus the oxygen worKing gas pressure P and subst-rate temperature T were studied. Specific features of both three-dimensional and two-dimensional epitaxy mechanisms corresponding to various deposition conditions were revealed. Difference between low and high P-T-value 3D epitaxy was established. The deposition of films with mirror-smooth surfaces and perfect interfaces is shown to be possible.

A novel composited process of solution treatment-hot gas forming and stress relaxation aging for titanium alloys

2021 ◽  
Vol 288 ◽  
pp. 116904
Author(s):  
Kehuan Wang ◽  
Yang Jiao ◽  
Xiaojuan Wu ◽  
Bao Qu ◽  
Xiaosong Wang ◽  
...  
Keyword(s):  
Stress Relaxation ◽  
Titanium Alloys ◽  
Solution Treatment ◽  
Hot Gas ◽  
Hot Gas Forming
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