Finite Element Prediction of Temperature Variation of Material and Dies in Aluminum Forging

2020 ◽  
Vol 830 ◽  
pp. 93-100
Author(s):  
Jae Dong Yoo ◽  
Tae Min Hwang ◽  
Man Soo Joun
Keyword(s):  
Aluminum Alloy ◽  
Temperature Rise ◽  
High Speed ◽  
Room Temperature ◽  
High Strain ◽  
Cold Forging ◽  
Multi Stage ◽  
Aluminum Forging ◽  
The Right ◽  
Finite Element Prediction

Investigation into behaviors of aluminum alloy to be metal formed at the room temperature is conducted in this study. An index is used to evaluate the sensitivity of temperature, that is, index of relative normalized temperature rise to steel called normalized temperature rise index per steel which helps researchers to obtain some insight on new materials based on experiences of steel forging. An investigation to an aluminum alloy shows that the index is quite high, implying that temperature effect as well as rate-dependence effect on the forming processes of aluminum alloy at the room temperature cannot be neglected. Some details of thermomechanical predictions of a relatively high-speed automatic multi-stage forging process of a yoke with highly deformed region are given to reveal the importance of temperature and/or strain rate even in cold forging of aluminum alloy parts with high speed and high strain. All manuscripts must be in English, also the table and figure texts, otherwise we cannot publish your paper. Please keep a second copy of your manuscript in your office. When receiving the paper, we assume that the corresponding authors grant us the copyright to use the paper for the book or journal in question. Should authors use tables or figures from other Publications, they must ask the corresponding publishers to grant them the right to publish this material in their paper. Use italic for emphasizing a word or phrase. Do not use boldface typing or capital letters except for section headings (cf. remarks on section headings, below).

Simulation of Multi-Stage Compressor at Off-Design Conditions

2017 ◽  
Author(s):  
Feng Wang ◽  
Mauro Carnevale ◽  
Luca di Mare ◽  
Simon Gallimore
Keyword(s):  
Mass Flow ◽  
High Speed ◽  
Eddy Viscosity ◽  
Turbulence Models ◽  
Viscosity Model ◽  
Eddy Viscosity Model ◽  
Multi Stage ◽  
Pressure Profiles ◽  
Non Linear ◽  
The Right

Computational Fluid Dynamics (CFD) has been widely used for compressor design, yet the prediction of performance and stage matching for multi-stage, high-speed machines remain challenging. This paper presents the authors’ effort to improve the reliability of CFD in multistage compressor simulations. The endwall features (e.g. blade fillet and shape of the platform edge) are meshed with minimal approximations. Turbulence models with linear and non-linear eddy viscosity models are assessed. The non-linear eddy viscosity model predicts a higher production of turbulent kinetic energy in the passages, especially close to the endwall region. This results in a more accurate prediction of the choked mass flow and the shape of total pressure profiles close to the hub. The non-linear viscosity model generally shows an improvement on its linear counterparts based on the comparisons with the rig data. For geometrical details, truncated fillet leads to thicker boundary layer on the fillet and reduced mass flow and efficiency. Shroud cavities are found to be essential to predict the right blockage and the flow details close to the hub. At the part speed the computations without the shroud cavities fail to predict the major flow features in the passage and this leads to inaccurate predictions of massflow and shapes of the compressor characteristic. The paper demonstrates that an accurate representation of the endwall geometry and an effective turbulence model, together with a good quality and sufficiently refined grid result in a credible prediction of compressor matching and performance with steady state mixing planes.

scholarly journals Automatic Multi-Stage Cold Forging of an SUS304 Ball-Stud with a Hexagonal Hole at One End

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5300
Author(s):  
Jong Bok Byun ◽  
Mohd Kaswandee Razali ◽  
Chang Ju Lee ◽  
Il Dong Seo ◽  
Wan Jin Chung ◽  
...  
Keyword(s):  
Flow Stress ◽  
Room Temperature ◽  
Cold Forging ◽  
Material Strength ◽  
Element Analysis ◽  
Multi Stage ◽  
Plastic Deformation Behavior ◽  
Die Stress ◽  
Hexagonal Hole ◽  
Good Strain

SUS304 stainless steel is characterized by combined tensile and compression testing, with an emphasis on flow stress at higher strain and temperature. The plastic deformation behavior of SUS304 from room temperature to 400 °C is examined and a general approach is used to express flow stress as a closed-form function of strain, strain rate, and temperature; this is optimal when the strain is high, especially during automatic multi-stage cold forging. The fitted flow stress is subjected to elastothermoviscoplastic finite element analysis (FEA) of an automatic multi-stage cold forging process for an SUS304 ball-stud. The importance of the thermal effect during cold forging, in terms of high material strength and good strain-hardening, is revealed by comparing the forming load, die wear and die stress predictions of non-isothermal and isothermal FEAs. The experiments have shown that the predictions of isothermal FEA are not feasible because of the high predicted effective stress on the weakest part of the die.

Full Field Measurements of the Dynamic Response of AA6061-T6 Aluminum Alloy Under High Strain Rate Compression and Torsion Loads

2012 ◽  
Author(s):  
Gbadebo Owolabi ◽  
Daniel Odoh ◽  
Akindele Odeshi ◽  
Horace Whitworth
Keyword(s):  
Aluminum Alloy ◽  
High Speed ◽  
High Strain ◽  
Shear Bands ◽  
Field Measurements ◽  
Image Correlation ◽  
Deformation Analysis ◽  
Deformation And Failure ◽  
Full Field ◽  
Structural Applications

Aluminum alloys exhibit an attractive combination of mechanical and physical properties such as high stiffness and low density, which favors their utilization in many structural applications. Thus, increasing the structural applications of aluminum alloy is the driving force for the need to adequately understand its deformation and failure mechanisms under various types of dynamic loading conditions. In this study, full field plastic deformation of AA6061-T6 aluminum alloy at high strain-rates under compressive and torsion loads are measured using split Hopkinson compression and torsion bars and a high speed digital image correlation system. The stress-strain curves obtained using the high speed digital cameras are compared with results obtained from the elastic waves in the compression and torsion bars. A post deformation analysis of the specimen also shows strain localization along narrow adiabatic shear bands in the AA6061-T6 alloy.

A First Room Temperature Stable and Jetable Solder Joint Encapsulant Adhesive

2011 ◽  
Vol 2011 (1) ◽  
pp. 000509-000515 ◽  
Author(s):  
Mary Liu ◽  
Wusheng Yin
Keyword(s):  
Solder Joint ◽  
High Speed ◽  
Room Temperature ◽  
Low Cost ◽  
White Paper ◽  
Solder Paste ◽  
Fine Pitch ◽  
Increasing Demand ◽  
The Right ◽  
Device Miniaturization

With the increasing demand of device miniaturization, high speed, more memory, more function, low cost, and more flexibility in device design and manufacturing chain, YINCAE has published a white paper on a first individual solder joint encapsulant which can eliminate underfilling process with at least five times solder joint increase and provide more flexibility for fine pitch and high density application. In order to meet the demand of manufacturing of high speed and low cost, YINCAE has invented a room temperature stable and jettable solder joint encapsulant adhesive – SMT 266. The invention of SMT 266 has allowed our customers to have more flexibility in their high-speed production line such as worry free on the work life of adhesive and workable jetting process. After being used in the customer field for a few years, the implementation of SMT266 has been approved improving the process yield, eliminating voids and cracks in solder joint, eliminating head-in-pillow issue for large component during lead free reflow process. The results from thermal cycling test indicated that the first failure cycles using SMT266 is high up to 6000 cycles, at least 4000 – 5000 cycles higher than other processes. The pull strength is 1.5 times higher than using solder paste plus underfilling process. All reliability data implied encapsulating each individual solder joint is the right direction to move toward. The enforcement mechanism will be discussed in our paper.

A Motion Study of a Manipulator for Transferring Microparts in a Multi Stage Former

2013 ◽  
Author(s):  
Rasoul Mahshid ◽  
Hans Nørgaard Hansen ◽  
Casper Hansen ◽  
Mogens Arentoft
Keyword(s):  
Production Rate ◽  
High Speed ◽  
Time Frame ◽  
Sufficient Information ◽  
High Speed Camera ◽  
Real Process ◽  
Multi Stage ◽  
Motion Study ◽  
Image Capturing ◽  
The Right

In the earlier studies, it was shown that a whole multi stage former can be divided into three major sub-sections, the positioning unit, the gripping unit and the forming unit. The two first units were investigated and related parameters and features of each were discussed. This research herein deals with the forming unit. For this research, the positioning unit and the gripping unit are applied to the forming unit including a micro press equipped with a die system. The analysis focuses on verifying the results already extracted from previous researches by implementing all mentioned units together. A motion study of the system gives an overview of different steps and movements inside the multi stage former. Significantly, increasing the production rate increases the acceleration and also causes the time frame tight. The time limitations put overlaps on the moving parts in terms of milliseconds. A high speed camera was used in the experiments with high resolution to show the details of the motion while enabling to detect any unwanted movement within milliseconds. Importantly, increasing the frequency of image capturing within the movement is another beneficial feature in the high speed camera in order to give sufficient information on critical movements where they may need sensors and enough time to ensure getting at the right position as programmed. In this research the production rate raised to 169 strokes per minute. The results show that the concept introduced for the manipulator works very well at a real process implementation. This significantly approves the techniques already were given to evaluate the precisio in the positioning unit and the gripping unit.

Effect of Severe Plastic Deformation by 120 deg ECAP or Shock Impact on 6061 Aluminum Alloy at High Strain Rates

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
T. Camalet ◽  
A. Rusinek ◽  
R. Bernier ◽  
M. Karon ◽  
R. Massion ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Room Temperature ◽  
High Strain ◽  
Material Behavior ◽  
Strain Rates ◽  
Plastic Deformations ◽  
6061 Aluminum Alloy ◽  
Angular Pressing ◽  
Ecap Process ◽  
Shock Impact

The aim of this paper is to analyze the macroscopic behavior of an aluminum alloy after severe plastic deformations (SPD). Samples of 6061 aluminum alloy are processed at room temperature by two techniques of SPD: equal channel angular pressing (ECAP) under quasi-static loading and impact under dynamic loading, using Taylor's test setup. In addition to the mechanical properties, the microstructure evolution of the material is investigated. Half of the samples are aged at 400 °C for 2 h, to remove internal stress in a commercial alloy in order to increase workability of the material. The evolution of the properties and the material behavior after 2, 4, 6, and 8 passes of the 120 deg ECAP process is investigated.

Superplasticity of Ultrafine-Grained Aluminum Alloy Processed by ECAP and Warm Rolling

2007 ◽  
Vol 551-552 ◽  
pp. 13-20
Author(s):  
Rinat K. Islamgaliev ◽  
N.F. Yunusova ◽  
M.A. Bardinova ◽  
A.R. Kilmametov ◽  
Ruslan Valiev
Keyword(s):  
Aluminum Alloy ◽  
Room Temperature ◽  
High Strain ◽  
High Strength ◽  
Warm Rolling ◽  
Grain Structure ◽  
Strain Rates ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Equiaxed Grain

The ultrafine-grained (UFG) 1421 aluminum alloy processed by equal channel angular pressing (ECAP) has demonstrated enhanced superplasticity at low temperature and high strain rates. This UFG material was successfully rolled at temperatures of 330-370oC retaining small grain size and equiaxed grain structure. The microstructure of the UFG alloy subjected to warm rolling (WR) was studied, and the mechanical properties of the ECAP+WR samples with UFG structures were investigated. We have found that the rolled material exhibited not only the enhanced superplasticity, but also high strength at room temperature.

A Study on Friction Stir Welding with Heating of Aluminum Alloy

2007 ◽  
Vol 353-358 ◽  
pp. 2041-2044
Author(s):  
Riichi Suzuki ◽  
Susumu Hioki ◽  
Naoki Yamamoto ◽  
Yuuta Kaneko ◽  
Takehiko Takahashi
Keyword(s):  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Welding Speed ◽  
High Speed ◽  
Room Temperature ◽  
High Efficiency ◽  
High Vacuum ◽  
Frictional Heat ◽  
Vacuum Vessel ◽  
Friction Stir

Conventional Friction Stir Welding (FSW) is that weld materials are joint at room temperature by stirring softened materials due to frictional heat of rotating tool. Therefore, high speed and high efficiency would be expected, as pre-heating make weld materials more softened, as well known that yield point goes lower due to heating. In this study, FSW was done to improve welding speed on FSW of aluminum alloy (A5052) for high vacuum vessel for processing of electronics devices. As the result, welding speed was 2.0 times to more than 3.0 at 300 oC comparing with conventional FSW at room temperature, using improved a milling machine with heater.

TEM study of phosphorus-implanted pseudomorphic Si0.88Ge0.12 on Si(100)

1995 ◽  
Vol 53 ◽  
pp. 468-469
Author(s):  
N. David Theodore ◽  
Donald Y.C Lie ◽  
J. H. Song ◽  
Peter Crozier
Keyword(s):  
Integrated Circuits ◽  
Heterojunction Bipolar Transistors ◽  
Integrated Circuit ◽  
High Speed ◽  
Room Temperature ◽  
Strain Relaxation ◽  
Bipolar Transistors ◽  
Sige Hbt ◽  
Integrated Circuit Manufacturing ◽  
Microstructural Behavior

SiGe is being extensively investigated for use in heterojunction bipolar-transistors (HBT) and high-speed integrated circuits. The material offers adjustable bandgaps, improved carrier mobilities over Si homostructures, and compatibility with Si-based integrated-circuit manufacturing. SiGe HBT performance can be improved by increasing the base-doping or by widening the base link-region by ion implantation. A problem that arises however is that implantation can enhance strain-relaxation of SiGe/Si.Furthermore, once misfit or threading dislocations result, the defects can give rise to recombination-generation in depletion regions of semiconductor devices. It is of relevance therefore to study the damage and anneal behavior of implanted SiGe layers. The present study investigates the microstructural behavior of phosphorus implanted pseudomorphic metastable Si0.88Ge0.12 films on silicon, exposed to various anneals.Metastable pseudomorphic Si0.88Ge0.12 films were grown ~265 nm thick on a silicon wafer by molecular-beam epitaxy. Pieces of this wafer were then implanted at room temperature with 100 keV phosphorus ions to a dose of 1.5×1015 cm-2.

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