scholarly journals Process Development for a Superplastic Hot Tube Gas Forming Process of Titanium (Ti-3Al-2.5V) Hollow Profiles

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1150
Author(s):  
Ricardo Trân ◽  
Franz Reuther ◽  
Sven Winter ◽  
Verena Psyk
Keyword(s):  
Titanium Alloys ◽  
Process Development ◽  
Chemical Properties ◽  
Superplastic Forming ◽  
Process Window ◽  
Forming Process ◽  
Time Curve ◽  
Pressure Time ◽  
Tool Technology ◽  
Good Agreement

Tube forming technologies based on internal forming pressures, such as hydroforming or hot tube gas forming, are state of the art to manufacture complex closed profile geometries. However, materials with excellent specific strengths and chemical properties, such as titanium alloys, are often challenging to shape due to their limited formability. In this study, the titanium alloy Ti-3Al-2.5V was processed by superplastic hot tube gas forming to manufacture a helically shaped flex tube. The forming process was investigated in terms of process simulation, forming tool technology and process window for the manufacturing of good parts. Within a simulation study, a strain rate optimized forming pressure–time curve was defined. With the newly developed tool design, forming temperatures up to 900 °C and internal forming pressures up to 7 MPa were tested. A process window to manufacture good parts without necking or wrinkling has been successfully identified. The experiment data showed good agreement with the numerical simulations. The detailed study of the process contributes to an in-depth understanding of the superplastic forming of Ti-3Al-2.5V during hot tube gas forming. Furthermore, the study shows the high potential of superplastic hot tube gas forming of titanium alloys for the manufacturing of helical flex tubes and bellows.

Numerical Analysis of Superplastic Forming for Sandwich Structure of 5083 Al-Alloy

2013 ◽  
Vol 739 ◽  
pp. 167-170
Author(s):  
Shou Fa Liu ◽  
Xiao Li Dou ◽  
Song Li Wu
Keyword(s):  
Sandwich Structure ◽  
Thickness Distribution ◽  
Superplastic Forming ◽  
Al Alloy ◽  
Maximum Strain ◽  
Forming Process ◽  
Element Analysis ◽  
Time Curve ◽  
Pressure Time ◽  
5083 Al Alloy

Finite element analysis of superplastic forming process for a hollow sandwich structure of aluminum alloy was carried out with MARC software, which can predict the thickness distribution of the structure, and optimize the pressure-time curve to control the maximum strain rate, which provided reference basis for the forming pressure of the subsequent experiment.

Design and Optimization of Honeycomb Corrugated Chaff Forming Roller

2014 ◽  
Vol 597 ◽  
pp. 213-218
Author(s):  
Xiao Ping Yang ◽  
Bo Zhong ◽  
Chang Jie Luo
Keyword(s):  
Analysis Software ◽  
Forming Process ◽  
Element Analysis ◽  
Time Curve ◽  
Forming Quality ◽  
Design And Optimization ◽  
Number Of Teeth ◽  
Stress Contour ◽  
Forming Characteristics ◽  
Good Agreement

Abstract. By analyzing the material properties and forming characteristics of the 0.8mm length side hexagon honeycomb corrugated chaff , we studied forming roller’s design and optimization while making corrugated chaffs used forming method and focus on the influence of the chamfer of teeth top edge and number of teeth to forming quality at the corrugated chaff corner .We used finite element analysis software ANSYS / LS-DYNA to simulate the forming process of corrugated chaff , studied the stress contour and stress-time curve of typical element, found the optimal chamfer of teeth top edge and number of teeth, then we used the designed forming roller to verify the effect of chaff forming . By comparison experimental and simulation results,we found good agreement between the two, when the chamfer of teeth top edge dj = 0.08mm, number of teeth z = 40, the chaff has the best forming quality .

Identification of the Location of Conductive Filaments Formed in Pt/NiO/Pt Resistive Switching Cells and Investigation on Their Properties

2012 ◽  
Vol 1430 ◽  
Author(s):  
Tatsuya Iwata ◽  
Yusuke Nishi ◽  
Tsunenobu Kimoto
Keyword(s):  
Resistive Switching ◽  
Chemical Properties ◽  
Cell Resistance ◽  
Forming Process ◽  
Tem Analysis ◽  
Cross Sectional ◽  
Size And Shape

ABSTRACTExact locations of conductive filaments formed in NiO-based resistive switching (RS) cells were detected by C-AFM, and their electrical as well as chemical properties were investigated. After a forming process, a part of top electrodes of Pt/NiO/Pt RS cells is deformed. NiO layers are also deformed, and conductive spots, i.e. filaments have been found preferentially along the edges of deformations. Detailed C-AFM investigation has revealed that variation of cell resistances originates from differences in size and shape of filaments, not their resistivity. Furthermore, cross-sectional TEM analysis has demonstrated that filaments determining cell resistance consist of reduced NiO with an inclusion of Pt.

Application of Tailored Heat Treated Blanks under Quasi Series Conditions

2007 ◽  
Vol 344 ◽  
pp. 383-390 ◽  
Author(s):  
Marion Merklein ◽  
Uwe Vogt
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Local Heat ◽  
Strength Distribution ◽  
Process Window ◽  
Short Term ◽  
Forming Process ◽  
Heat Treated ◽  
Set Up ◽  
The Impact

Tailored Heat Treated Blanks (THTB) are blanks that exhibit locally different strength specifically optimized for the succeeding forming process. The strength distribution is set by a local, short-term heat treatment modifying the mechanical properties of the material. Hence, THTB allow enhancing forming limits significantly leading to shorter and more robust manufacture process chains. In order to qualify the use of THTB under quasi series conditions, the interdependencies of the blank’s local heat treatment and the entire process chain of the car body manufacture have to be analyzed. In this respect, the impact of a short-term heat treatment on the mechanical properties of AA6181PX, a commonly used aluminum alloy in today’s car bodies, was studied. Also the influence of a short-term heat treatment on the coil lubricant, usually already applied by the material supplier, was given a closer look. Based on these experiments process restrictions for the application of THTB in an industrial automotive environment were derived and a process window for the THTB design was set up. In conclusion, strategies were defined how to enhance the found process boundaries leading to a more robust process window.

Gas-phase oxidation of butene-2

1958 ◽  
Vol 244 (1238) ◽  
pp. 331-344 ◽  
Keyword(s):  
Gas Phase ◽  
Pressure Change ◽  
Reaction Products ◽  
Peroxide Formation ◽  
Time Curve ◽  
Pressure Time ◽  
Initial Oxygen ◽  
Gas Phase Oxidation ◽  
Reactive Radicals ◽  
Reaction Processes

The gas-phase thermal oxidation of butene-2 has been examined over the temperature range 289 to 395°C. No difference in behaviour of the cis and trans forms could be detected. At the higher temperatures the reaction resembled that of the oxidation of propylene in the shape of the pressure-time curve and in the identity of many of the reaction products. At the lower temperatures a decrease in pressure partly due to peroxide formation followed the induction period, and by the end of this time much of the initial oxygen had been consumed. At all temperatures excess olefin produced an apparent inhibiting effect manifested by a decreased yield of carbon monoxide and a fall-off in the maximum rate of pressure change and total pressure change. Reaction processes are discussed, and it is suggested that a peroxide precedes the formation of acetaldehyde. Branching occurs largely through reaction of acetyl radicals produced from the acetaldehyde. The inhibiting effects produced by excess olefin are attributed to the replacement of reactive radicals by the less reactive allylic-type radicals, and the addition reactions of olefin at higher olefin concentrations lead to polymerization and a low or negative overall pressure change.

Design in Superplastic Forming Process by Rigid Visco Plastic Shell FEM

1996 ◽  
Vol 243-245 ◽  
pp. 735-738 ◽  
Author(s):  
Kai Feng Zhang ◽  
Z.R. Wang ◽  
Xiao Ming Lai ◽  
G.L. Kan
Keyword(s):  
Superplastic Forming ◽  
Plastic Shell ◽  
Forming Process

scholarly journals Chemical properties and fertility analysis of dredger-fill silt during soil formation: The tianjin dredge–fill project

2017 ◽  
Author(s):  
Huijun Gu ◽  
Xin Sui ◽  
Guogang Zhang ◽  
Meiqing Jia
Keyword(s):  
Nitrate Nitrogen ◽  
Chemical Properties ◽  
Soil Formation ◽  
Principal Component ◽  
Available Phosphorus ◽  
Forming Process ◽  
Factors Affecting ◽  
Ecological Problems ◽  
Dredger Fill ◽  
Fertility Analysis

Dredger-fill silt has been used in the port of Tianjin, China to reclaim land; however, the dredger-fill silt has no soil ecological function. Translating the silt into soil rapidly and accelerating the soil-forming process are key to solving the ecological problems of the Dredge–Fill project. This study measured 15 chemical properties of the dredger-fill silt for 8 years of the soil forming process to explore fertility changes and the critical factors affecting soil formation. The results showed that: (1) the salinity of silt changed from severe to mild with a reduction in Na+ and Cl- concentration. Other ion concentrations changed slightly. (2) Effective nutrients significantly decreased during soil formation. Soil organic matter (SOM)，the nitrate-nitrogen, available phosphorus (A-P) and available potassium (A-K) decreased by 26.22%, 86.23%, 45.92%, 33.61% respectively, indicating severe nutrients loss. (3) Principal component analysis showed that silt fertility decreased significantly and the total soil fertility loss was severe. This study has significance for the artificial improvement of silt.

scholarly journals Optimization of Superplastic Forming Process of AA7075 Alloy for the Best Wall Thickness Distribution

2021 ◽  
Vol 6 (4) ◽  
pp. 251-261
Author(s):  
Manh Tien Nguyen ◽  
Truong An Nguyen ◽  
Duc Hoan Tran ◽  
Van Thao Le
Keyword(s):  
Wall Thickness ◽  
Deformation Temperature ◽  
Numerical Optimization ◽  
Thickness Distribution ◽  
Superplastic Forming ◽  
Forming Process ◽  
Wall Thickness Distribution ◽  
Surface Method ◽  
Series Of Experiments ◽  
The Relationship

This work aims to optimize the process parameters for improving the wall thickness distribution of the sheet superplastic forming process of AA7075 alloy. The considered factors include forming pressure p (MPa), deformation temperature T (°C), and forming time t (minutes), while the responses are the thinning degree of the wall thickness ε (%) and the relative height of the product h*. First, a series of experiments are conducted in conjunction with response surface method (RSM) to render the relationship between inputs and outputs. Subsequently, an analysis of variance (ANOVA) is conducted to verify the response significance and parameter effects. Finally, a numerical optimization algorithm is used to determine the best forming conditions. The results indicate that the thinning degree of 13.121% is achieved at the forming pressure of 0.7 MPa, the deformation temperature of 500°C, and the forming time of 31 minutes.

Numerical and Experimental Investigation on the Hybrid Superplastic Forming of the Conical Mg Alloy Component

2018 ◽  
Vol 385 ◽  
pp. 391-396
Author(s):  
Mei Ling Guo ◽  
Ming Jen Tan ◽  
Xu Song ◽  
Beng Wah Chua
Keyword(s):  
Electron Backscatter Diffraction ◽  
Thickness Distribution ◽  
Superplastic Forming ◽  
Test Results ◽  
Forming Process ◽  
Hyperbolic Sine ◽  
Coarse Grains ◽  
Hot Drawing ◽  
Material Forming ◽  
Backscatter Diffraction

Hybrid superplastic forming (SPF) is a novel sheet metal forming technique that combines hot drawing with gas forming process. Compared with the conventional SPF process, the thickness distribution of AZ31B part formed by this hybrid SPF method has been significantly improved. Additionally, the microstructure evolution of AZ31 was examined by electron backscatter diffraction (EBSD). Many subgrains with low misorientation angle were observed in the coarse grains during SPF. Based on the tensile test results, parameters of hyperbolic sine creep law model was determined at 400 oC. The hybrid SPF behavior of non-superplastic grade AZ31B was predicted by ABAQUS using this material forming model. The FEM results of thickness distribution, thinning characteristics and forming height were compared with the experimental results and have shown reasonable agreement with each other.

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