scholarly journals Modelling Microstructure Evolution in ATI 718Plus® Alloy

2016 ◽  
Vol 716 ◽  
pp. 352-359
Author(s):  
Aleksey Reshetov ◽  
Olga Bylya ◽  
Michal Gzyl ◽  
Malgorzata Rosochowska ◽  
Paul Blackwell
Keyword(s):  
Finite Element Analysis ◽  
Grain Size ◽  
Finite Element ◽  
Grain Growth ◽  
Microstructure Evolution ◽  
Deformation Process ◽  
Main Trend ◽  
Main Body ◽  
Element Analysis ◽  
Average Grain Size

The present study details the results of finite element analysis (FEA) based predictions for microstructure evolution in ATI 718Plus® alloy during the hot deformation process. A detailed description of models for static grain growth and recrystallisation is provided. The simulated average grain size is compared with those experimentally measured in aerofoil parts after forging trials. The proposed modified JMAK model has proved to be valid in the main body of the forging. The results predicted for the surface are less accurate. The recrystallised grain size on the surface is smaller than in the centre of the part which corresponds to the experimental results and reflects the main trend.

Microstructure Prediction during Hot Deformation Using New Dynamic Recrystallization Model and Finite Element Analysis

2014 ◽  
Vol 611-612 ◽  
pp. 483-488
Author(s):  
Ho Won Lee ◽  
Young Seon Lee ◽  
Seong Hoon Kang
Keyword(s):  
Finite Element Analysis ◽  
Grain Size ◽  
Finite Element ◽  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Pure Copper ◽  
Hot Compression ◽  
State Variables ◽  
Element Analysis ◽  
Average Grain Size

In this study, dynamic recrystallization during nonisothermal hot deformation was numerically simulated by finite element analysis and new physically based dynamic recrystallization model. The dynamic recrystallization model was developed based on mean field approach by assuming grain aggregate as representative volume element. For each grain aggregate, changes of state variables such as dislocation density and grain size were calculated using three sub-models for work hardening, nucleation, and nucleus growth. The developed dynamic recrystallization model was validated by comparing with isothermal hot compression of pure copper. Finally, developed dynamic recrystallization model was combined with finite element method to predict the local changes of microstructure and average grain size during nonisothermal hot compression of pure copper and hot tube extrusion of austenitic stainless steel. The simulation results were in reasonably good agreement with experimentally determined microstructures.

scholarly journals Finite element analysis of the grain size effect on diffusion in polycrystalline materials

2014 ◽  
Vol 95 ◽  
pp. 187-191 ◽  
Author(s):  
V. Lacaille ◽  
C. Morel ◽  
E. Feulvarch ◽  
G. Kermouche ◽  
J.-M. Bergheau
Keyword(s):  
Finite Element Analysis ◽  
Grain Size ◽  
Finite Element ◽  
Size Effect ◽  
Polycrystalline Materials ◽  
Grain Size Effect ◽  
Element Analysis

Impact of Grain Structure and Material Properties on Via Extrusion in 3D Interconnects

2015 ◽  
Vol 12 (3) ◽  
pp. 118-122 ◽  
Author(s):  
Tengfei Jiang ◽  
Chenglin Wu ◽  
Jay Im ◽  
Rui Huang ◽  
Paul S. Ho
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Grain Size ◽  
Finite Element ◽  
Analytical Model ◽  
Material Properties ◽  
Grain Structure ◽  
Element Analysis ◽  
Silicon Vias ◽  
The Relationship

In this article, the effects of Cu microstructure on the mechanical properties and extrusion of through-silicon vias (TSVs) were studied based on two types of TSVs with different microstructure. A direct correlation was found between the grain size and the mechanical properties of the vias. Both an analytical model and finite element analysis (FEA) were used to establish the relationship between the mechanical properties and via extrusion. The effect of via/Si interface on extrusion was also studied by FEA. The results suggest small and uniform grains in the Cu vias, as well as stronger interfaces between the via and Si led to smaller via extrusion, and are thus preferable for reduced via extrusion failure and improved TSV reliability.

Finite Element Analysis on Microstructure Evolution of Hot Ring Rolling Process

2008 ◽  
Vol 575-578 ◽  
pp. 1455-1460 ◽  
Author(s):  
Zhi Chao Sun ◽  
He Yang ◽  
Xin Zhe Ou
Keyword(s):  
Grain Size ◽  
Microstructure Evolution ◽  
Volume Fraction ◽  
Small Deformation ◽  
Local Area ◽  
Rolling Process ◽  
Ring Rolling ◽  
Rigid Plastic ◽  
Element Analysis ◽  
Average Grain Size

Hot ring rolling (HRR) is a 3D unsteady-state and coupled thermo-mechanical process, the metal undergoes complicated unequal deformation and microstructure evolution. In this paper a 3D rigid-plastic and coupled thermo-mechanical FEM model for hot ring rolling was developed based on DEFORM3D platform, taking dynamic recrystallization (DRX) volume fraction, DRX grain size, recystallization volume fraction and average grain size as objects, the mechanism of material microstructure evolution and distributions in HRR process are thoroughly studied. The results show that: with the HRR progressing, the DRX volume fraction, volume fraction, DRX grain size and average grain size have the similar distributing characteristic, and the distribution zones expand from a small local area into the whole ring strip, then diffuse to the mid-layer of ring with small deformation, their distributions become more uniform. Meanwhile with increase of deformation, the values of the DRX volume fraction and recrystallization volume fraction augment, i.e. the degree of recystallization increases. The DRX grain size also augments due to local high temperature, while the average grain size decreases. In general during HRR process the distributions of DRX volume fraction, recrystallization volume fraction, DRX grain size, and average grain size are ununiform due to unequal deforming in HRR process.

Validation of a Conventional Finite Element Model for Simulation of a Micropunching Process

2014 ◽  
Author(s):  
Amrit Sagar ◽  
Christopher R. Nehme ◽  
Anil Saigal ◽  
Thomas P. James
Keyword(s):  
Grain Size ◽  
Finite Element ◽  
Bulk Material ◽  
Foil Thickness ◽  
Homogeneous Material ◽  
Element Analysis ◽  
Hardening Material ◽  
Material Inhomogeneity ◽  
Finite Element Software ◽  
Average Grain Size

Finite element analysis (FEA) of metal microforming processes may require Crystal Plasticity Finite Element (CPFE) formulations to incorporate material inhomogeneity as feature size approaches grain size. Presently, it is unknown if the micropunching process, where holes are formed by shearing thin metal foils with a thickness on the same scale as grain size, can be accurately simulated by using the material’s bulk material properties or if CPFE is required. In the current research, validity of conventional FEA in simulating micropunching is investigated as CPFE formulations have yet to be integrated with most commercially available programs. Using DEFORM finite element software, strain hardening and strain rate hardening material models were employed to approximate flow stress when punching 200 μm diameter holes in 25 μm thick annealed copper foil. For validation of peak punching force, micro holes were fabricated with a nominal diameter of 200 μm for die clearances ranging from 7.6% to 48% of material thickness. The average grain size of the foil was determined to be approximately 47 μm. Therefore, micropunching was predominantly through a single grain across foil thickness and less than a grain in the direction of radial die clearance. Results indicate that the homogeneous material model in DEFORM is capable of predicting the maximum punching forces with reasonable accuracy, concluding that a CPFE model is not necessary for this category of micropunching. Regardless of die clearance, the maximum punching force was approximately 3 N.

Microstructure Evolution in Bulk Nanostructured Copper during Repeated Cold Rolling

2012 ◽  
Vol 248 ◽  
pp. 43-47
Author(s):  
Lei Liu ◽  
Han Zhuo Zhang ◽  
Qin Lan Zhao
Keyword(s):  
Grain Size ◽  
Cold Rolling ◽  
Grain Growth ◽  
Microstructure Evolution ◽  
Room Temperature ◽  
Maximum Value ◽  
Deformation Stages ◽  
Average Grain Size ◽  
Dislocation Interactions ◽  
Room Temperature Rolling

Room temperature rolling tests were performed on a bulk nanostructured Cu with an average grain size of 90 nm. The results indicated a high thickness reduction ( ) of 92% without crack and an increased {220} texture as the rolling processes continued. Microstructure evolution of the deformed nanostructured Cu could be characterized by several deformation stages. Grain growth and coalescence was prevalent in the early deformation stage, while grain boundaries were impaired and replaced by dislocation interactions when 24%. Microhardness of the deformed nanostructured Cu increased sharply to a maximum value of 1.61 GPa at 8% and then slightly decreased to 1.58 GPa at 92%.

Hardness of thin Films of Nanocrystalline Silver and Nickel Composites Studied by Nanoindentation and Finite Element Analysis

1995 ◽  
Vol 400 ◽  
Author(s):  
Boqin Qiu ◽  
Yang-Tse Cheng ◽  
James P. Blanchard
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Finite Element ◽  
Two Phase ◽  
Element Analysis ◽  
Gas Condensation ◽  
Nano Crystalline ◽  
Average Grain Size ◽  
Nickel Composites ◽  
Xrd And Tem

AbstractWhile gas condensation and mechanical alloying have been used to produce nano-phase powders, an effective method of applying these powders as coatings is still lacking. Furthermore, fundamental studies of the mechanical properties of nano-phase powders may be complicated by the porosity associated with consolidation processes. Recently, we have made nano-crystalline composite thin films of Ag-Mo and Ag-Ni by depositing two immiscible elements simultaneous onto substrates. We found, using XRD and TEM, that the average grain size varies from 10 to 100 nm by choosing an appropriate substrate temperature. Nanoindentation measurements showed the hardness of the composite is increased four times by reducing the grain-size of both phases from 100 to 10 nm. The load vs. displacement curves were simulated using a finite element method (ABAQUS). A relationship between the hardness of the two-phase composite and the yield strength of each phase is obtained.

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