scholarly journals Evaluation of the Formability of AA2198-T3 Al-Li alloy in Warm Sheet Hydroforming

2021 ◽  
Author(s):  
Hui Wang ◽  
Sijia Cheng ◽  
Zhuang Ye ◽  
Tianli Wu ◽  
Kai Jin ◽  
...  
Keyword(s):  
Room Temperature ◽  
Cylindrical Part ◽  
Chamber Pressure ◽  
Main Role ◽  
Cavity Pressure ◽  
Sheet Hydroforming ◽  
Element Simulation ◽  
Forming Temperature ◽  
Uniform Wall ◽  
Fracture Morphologies

Abstract This study aims to investigate the formability of the AA2198-T3 Al-Li alloy in hydrodynamic deep drawing (HMDD), through experimentation and finite element simulation. The effects of the most critical factors were studied: die cavity pressure and forming temperature. The Gurson−Tvergaard−Needleman model (GTN model) was employed to analyze the formability of AA2198-T3 Al-Li alloy and predict the fracture in the hydroforming of a cylindrical part. Both the numerical and experimental results showed that the increase of the pressure inside the liquid chamber, within a certain range, contributes to improve the formability of the alloy. Increasing the temperature would reduce the required pressure for sheet hydroforming. Notably, the appropriate chamber pressure was beneficial to form good quality parts with a relatively uniform wall thickness. By analyzing the fracture morphologies, the brittle fracture of AA2198-T3 plays a main role at room temperature, but the ductile fracture was shown at the elevated temperature.

Extensive deformation behavior of an all-oxide Al2O3-TiO2 nanostructured multilayer ceramic at room temperature

2009 ◽  
Vol 24 (11) ◽  
pp. 3387-3396 ◽  
Author(s):  
Arcan F. Dericioglu ◽  
Y.F. Liu ◽  
Yutaka Kagawa
Keyword(s):  
Cross Sections ◽  
Deformation Behavior ◽  
Room Temperature ◽  
Temperature Deformation ◽  
Relative Movement ◽  
Element Simulation ◽  
Columnar Grains ◽  
Multilayer Ceramic ◽  
Extensive Deformation ◽  
Indentation Response

An all-oxide Al2O3-TiO2 ceramic multilayer composed of 10–100 nm thick alternating layers was fabricated using the reactive magnetron sputtering process. Microindentation tests were carried out on the multilayer ceramic followed by microstructural observations of the cross-sections of the indented sites to characterize the indentation response of the system. During the observations, it was noted that an extensive room temperature “deformation” occurred in the multilayer ceramic material. The material shows a thickness reduction of as much as ∼40% under a conical indenter at 300 mN of load without microcracking and dislocation-assisted deformation. The room temperature deformation mechanism is governed by the relative movement and rearrangement of the anisotropic nanoscale columnar grains along the intergranular boundaries containing elongated voids. The relative sliding along the intergranular boundaries, and the subsequent granular rotation under indentation were well captured by finite element simulation.

Flow Stress Experimental Determination for Warm-Forming Process

2011 ◽  
Author(s):  
Ting Fai Kong ◽  
Luen Chow Chan ◽  
Tai Chiu Lee
Keyword(s):  
Stainless Steel ◽  
Flow Stress ◽  
Room Temperature ◽  
Warm Forming ◽  
Recrystallization Temperature ◽  
Process Conditions ◽  
Compression Tests ◽  
Forming Process ◽  
Forming Temperature ◽  
Flow Stress Data

Warm forming is a manufacturing process in which a workpiece is formed into a desired shape at a temperature range between room temperature and material recrystallization temperature. Flow stress is expressed as a function of the strain, strain rate, and temperature. Based on such information, engineers can predict deformation behavior of material in the process. The majority of existing studies on flow stress mainly focus on the deformation and microstructure of alloys at temperature higher than their recrystallization temperatures or at room temperature. Not much works have been presented on flow stress at warm-forming temperatures. This study aimed to determine the flow stress of stainless steel AISI 316L and titanium TA2 using specially modified equipment. Comparing with the conventional method, the equipment developed for uniaxial compression tests has be verified to be an economical and feasible solution to accurately obtain flow stress data at warm-forming temperatures. With average strain rates of 0.01, 0.1, and 1 /s, the stainless steel was tested at degree 600, 650, 700, 750, and 800 °C and the titanium was tested at 500, 550, 600, 650, and 700 °C. Both materials softened at increasing temperatures. The overall flow stress of stainless steel was approximately 40 % more sensitive to the temperature compared to that of titanium. In order to increase the efficiency of forming process, it was suggested that the stainless steel should be formed at a higher warm-forming temperature, i.e. 800 °C. These findings are a practical reference that enables the industry to evaluate various process conditions in warm-forming without going through expensive and time consuming tests.

Ultra-Shallow Doping of GaAs with Mg, Cr, Mn and B Using Plasma Stimulated Room-Temperature Diffusion

2020 ◽  
Vol 20 (3) ◽  
pp. 1878-1883
Author(s):  
Lei Li ◽  
Ruixiang Hou ◽  
Lili Zhang ◽  
Yihang Chen ◽  
L. Yao ◽  
...  
Keyword(s):  
Room Temperature ◽  
Physical Mechanism ◽  
Plasma Sheath ◽  
Main Role ◽  
External Bias ◽  
Temperature Diffusion ◽  
Plasma Doping ◽  
Order Of Magnitude ◽  
Impurity Ion ◽  
First Time

It is demonstrated that Mg, Cr, Mn and B can be doped close to GaAs surface by plasma doping without external bias at room temperature (RT). The process only takes a few minutes, and impurity densities in the range of 1018–1021/cm3 can be achieved with doping depths about twenty nanometers. The experiment results are analyzed and the physical mechanism is tentatively explained as follows: during the doping process, impurity ion implantation under plasma sheath voltage takes place, simultaneously, plasma stimulates RT diffusion of impurity atom, which plays the main role in the doping process. The enhanced RT diffusion coefficients of Mg, Cr, Mn and B in GaAs are all in the order of magnitude of 10-15 cm2sec-1. This is reported for the first time among all kinds of plasma assisted doping methods.

Effect of Annealing Treatment on the Properties of Cold Rolled Copper Foil

2018 ◽  
Vol 921 ◽  
pp. 231-235
Author(s):  
Ke Bin Sun ◽  
Yan Feng Li ◽  
Ye Xin Jiang ◽  
Guo Jie Huang ◽  
Xue Shuai Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cold Rolling ◽  
Copper Foil ◽  
Room Temperature ◽  
Annealing Treatment ◽  
Test Machine ◽  
Cold Rolled ◽  
Rolled Copper Foil ◽  
Fracture Morphologies

Copper foils with 91% cold rolled deformation annealed at temperature between 140°C and 170 °C.The microstructures were observed by EBSD. The mechanical properties were measured at room temperature by tensile test machine and the fracture morphologies observed by SEM. After annealed at 150 °C, recrystallization begins to occur, while the elongation increases evidently and tensile strength decreases sharply. When the temperature rises to 170 °C, recrystallization is complete and the grain starts to grow. When the foils are annealed at 140 °C, it exhibits a strong cold rolling textures characterized by Brass {011}<211> and Cu {112}<111>. After annealed at 170 °C, there are olny weak Brass {011}<211> texture.

scholarly journals The Role of Graphitic Carbon Nitride in the Formulation of Copper-Free Friction Composites Designed for Automotive Brake Pads

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 123
Author(s):  
Vlastimil Matějka ◽  
Mara Leonardi ◽  
Petr Praus ◽  
Giovanni Straffelini ◽  
Stefano Gialanella
Keyword(s):  
Carbon Nitride ◽  
Room Temperature ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Main Role ◽  
Brake Pads ◽  
Pin On Disc ◽  
Brake Lining ◽  
Automotive Brake

In this study, graphitic carbon nitride (g-C3N4, labelled as gCN) was tested in the formulation of copper-free (Cu-free) friction mixtures, which are potentially interesting for brake pad manufacturing. Three formulations of friction composites were prepared starting from a common Cu-free master batch: (i) without graphite, (ii) with graphite and (iii) with gCN. The mixtures were pressed in the form of pins by hot-press moulding. The friction-wear performance of the prepared pins was investigated using a pin-on-disc (PoD) test at room temperature (RT), high temperature (HT) (400 °C) and, again, at room temperature (H-RT). The values of the friction coefficient (µ) for the composites with gCN (or graphite) were as follows: (i) RT test, µRT = 0.52 (0.47); (ii) HT test, µHT = 0.37 (0.37); (iii) RT after the HT tests, µH-RT = 0.49 (0.39). With respect to wear resistance, the samples with graphite performed better than the samples without this solid lubricant. To the best of our knowledge, this is the first report regarding the evaluation of the role of gCN in friction composites designed for automotive brake lining applications. The results indicate the main role of gCN as a soft abrasive.

Room Temperature Hydrogen Gas Sensitivity of Nanocrystalline-Doped Tin Oxide Sensor Incorporated into MEMS Device

2004 ◽  
Vol 828 ◽  
Author(s):  
Satyajit Shukla ◽  
Rajnikant Agrawal ◽  
Lawrence Ludwig ◽  
Hyoung Cho ◽  
Sudipta Seal
Keyword(s):  
Tin Oxide ◽  
Room Temperature ◽  
Microelectromechanical Systems ◽  
Sol Gel ◽  
High Sensitivity ◽  
Hydrogen Gas ◽  
Chamber Pressure ◽  
Gas Sensitivity ◽  
Film Sensor ◽  
Mems Device

ABSTRACTNanocrystalline indium oxide (In2O3)-doped tin oxide (SnO2) thin film sensor has been sol-gel dip-coated on a microelectromechanical systems (MEMS) device. The micro-sensor device is successfully utilized to sense ppm level H2 at room temperature with high sensitivity. The chamber pressure has no pronounce effect on the room temperature H2 sensitivity.

Modeling and Experiments on an Oscillating Water Column Using a Self-Adaptive Air Turbine and Shutter

2013 ◽  
Author(s):  
Patrick Lorenz ◽  
Richard W. Kimball ◽  
Frank DiBella ◽  
Richard Smith ◽  
Scott Ring
Keyword(s):  
Numerical Model ◽  
Water Column ◽  
Potential Flow ◽  
Numerical Models ◽  
Air Flow ◽  
Chamber Pressure ◽  
Oscillating Water Column ◽  
Cavity Pressure ◽  
Wells Turbine ◽  
Physical Scale

This paper presents model-scale measurements and numerical models of a floating oscillating water column (OWC) system, consisting of an air cavity coupled with a Wells-type turbine energy extraction device. As waves travel through the OWC, air pressure cycles are generated. The oscillating water column captures the resulting pneumatic energy by directing the chamber pressure and air flow through the Wells turbine. A special feature of the system is a shuttering device that momentarily interrupts turbine air flow. The shuttering device is used to control the cavity pressure for optimum turbine performance. Shuttering in this manner can be shown to improve overall system efficiency up to 20% pressure. Physical scale models of the OWC system were tested in a wave tank at Maine Maritime Academy (MMA) at 1/30th scale as well as elastomeric diaphragm testing at 1/15th scale, under various conditions. Data from these tests, including cavity pressure response, turbine flow rate, and computed fluid power are discussed. In addition, numerical models of the system were developed using a parametric spring-mass-dashpot methodology and as well as a potential flow model derived for cavity geometry in a global wave field (see section 3). This paper describes the OWC system with adaptive shutter; comparison of experimental measurements to numerical model predictions; numerical model implementation and measurements of energy absorption/resonant effects within the chamber; and a potential flow derivation.

Numerical Simulation and Experimental Research on the Deformation of Equal Channel Angular Pressing of Al-5Ti-1B Aluminum Alloy

2013 ◽  
Vol 815 ◽  
pp. 251-255
Author(s):  
Wen Yu Zhang ◽  
Xian Lan Liu ◽  
Xiao Ming Jin
Keyword(s):  
Equal Channel Angular Pressing ◽  
Room Temperature ◽  
Effective Strain ◽  
Optical Microscope ◽  
Test Machine ◽  
Uniform Deformation ◽  
Outer Corner ◽  
Angular Pressing ◽  
Element Simulation ◽  
Simulation Results

The effective strain size and distribution of Al-5Ti-1B alloy deformed by equal channel angular pressing (ECAP) were investigated through the finite element simulation by the die with outer corner ψ=0°, 20°, 30° and the friction coefficient f=0, 0.2, 0.3. The simulation results show that the effective strains decrease with the increase of the outer corner ψ from 0° to 30° with a constant f; the more uniform deformation were obtained under the conditions of large friction than that of small friction. Al-5Ti-1B alloy was produced by once path ECAP at room temperature under the die with the corner angle φ=90° and ψ=20°. The optical microscope and compressing test machine were performed. The results indicate that the grain size was obviously refined. The yield strength increased by 37.5% from 142.0MPa to 195.3MPa, and hardness increased by 24% from 45.2HV to 55.9 HV.

Warm Hydroformability and Mechanical Properties of Pre- and Post- Heat Treated Al6061 Tubes

2007 ◽  
Vol 29-30 ◽  
pp. 87-90 ◽  
Author(s):  
Hyae Kyung Yi ◽  
Jung Hwan Lee ◽  
Young Seon Lee ◽  
Young Hoon Moon
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Room Temperature ◽  
Cost Effective ◽  
Bulge Test ◽  
Axial Tensile ◽  
Heat Treated ◽  
Shaped Tube ◽  
Forming Temperature ◽  
Warm Hydroforming

Warm hydroformability and mechanical properties of pre- and post- heat treated Al6061 tubes were investigated in this study. For the investigation, as-extruded, fully annealed and T6- treated Al 6061 seamless tubes were prepared. To evaluate the hydroformability, uni-axial tensile test and free bulge test were performed at room temperature and 200ÓC. Also mechanical properties of hydroformed part at various pre- and post-heat treatments were evaluated by tensile test. The tensile test specimens were obtained from hexagonal shaped tube hydroformed at 200ÓC forming temperature. As a result, hydroformability of fully annealed tube is 25% higher than that of extruded tube. The tensile strength and elongation were more than 330MPa and 12%, respectively, when hydroformed part was T6 treated after warm hydroforming. However, hydroformed part using T6 pre treated tube represents low elongation, 8%. Therefore, the T6 treatment after hydroforming for as-extruded tube is proved to be the most cost-effective among various processing conditions.

Compressive Behavior of AA6061 at Room Temperature and Validation of the FE Model Based on Optical 3D Measurement Technique

2013 ◽  
Vol 594-595 ◽  
pp. 909-913
Author(s):  
A.B. Abdullah ◽  
Z. Samad
Keyword(s):  
Finite Element ◽  
Measurement Technique ◽  
Room Temperature ◽  
Element Model ◽  
Surface Measurement ◽  
Fe Model ◽  
Cold Upsetting ◽  
Element Simulation ◽  
The Finite Element Model ◽  
Good Agreement

Recently, manufacturing process simulation using finite element (FE) model become important. Therefore, validation of the finite element model is crucial. This study will present validation of 2D finite element simulation of cold heading at room temperature. Validation of the simulation model is carried out by comparing the resulted bulge profile of the cold upsetting specimen to the profile of the specimen, which is obtained from an optical 3D surface measurement technique namely Infinite Focus Alicona system. Based on the result, both profiles show a very good agreement.

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