scholarly journals Investigating the relationship between grain orientation and surface height changes in nickel polycrystals under tensile plastic deformation

2019 ◽  
Vol 134 ◽  
pp. 165-175 ◽  
Author(s):  
K. Balusu ◽  
R. Kelton ◽  
E.I. Meletis ◽  
H. Huang
Keyword(s):  
Plastic Deformation ◽  
Grain Orientation ◽  
The Relationship

True Stress and Shakedown Analysis of Pressure Vessel which under Cyclic Loading to Plastic Deformation

2014 ◽  
Vol 590 ◽  
pp. 8-12
Author(s):  
Xiao Liang Jia ◽  
Yi Liang Zhang ◽  
Jing Wang ◽  
Chun Bo Wang
Keyword(s):  
Plastic Deformation ◽  
Constitutive Model ◽  
Pressure Vessel ◽  
Axial Stress ◽  
Water Pressure ◽  
True Strain ◽  
Test System ◽  
True Stress ◽  
Plastic Shakedown ◽  
The Relationship

The aim of this study is to discuss the plastic shakedown and true stress of the cyclically loaded pressure vessel. A thin-walled cylinder pressure vessel is made according to actual working state and a water pressure test system is built. The vessel is loaded to different strain levels of plastic deformation first. Then it is loaded cyclically to shakedown state. The relationship between plastic strain and shakedown range is given based on numerous experiments. The constitutive model of the true stress-true strain of the vessel is obtained. The experimental results show that the ratcheting obviously occurred when the vessel is cyclically loaded to plastic deformation. The true stress-strain constitutive model which is presented in this paper can show appropriately the constitutive relation of the vessel when it is under multi-axial stress state. The application of uniaxial shakedown constitutive model has been demonstrated in this study.

Finish Roll Forming of Spur Gears for High Efficiency

2000 ◽  
Author(s):  
Seizo Uematsu ◽  
Masana Kato
Keyword(s):  
Plastic Deformation ◽  
High Speed ◽  
High Efficiency ◽  
Tooth Profile ◽  
Roll Forming ◽  
Spur Gears ◽  
Design Data ◽  
Constant Center ◽  
The Relationship ◽  
Center Distance

Abstract Finish roll forming under the constant center distance by forced feed of tool can be conceived as a method of eliminating errors in conventional form rolling under constant loads. This method generates a high-precision tooth profile by low-speed form rolling when a high rigid screw or cam is used as loading parts. In this study, the high-speed rolling conditions of this method for necessary to be applied in practical situations are discussed. The following conclusions are obtained. When the following design data are given (module, number of teeth, addendum modification coefficient, prescribed design precision, and material characteristics), the accuracy of rolled gear can be predicted from the relationship between the required feed for the tool and the theoretically calculated plastic deformation on the tooth profile. These conclusions are verified experimentally. For example, the tooth accuracy of rolled gears with module 5 can improve from JIS class 3 to JIS class 0 or 1 when the load Fmax is 4 to 5kN and the pitch line velocity is 7 m/min.

Grrain Orientations and their Influence on Precipitation in Hot Compressed Columnar Grains in Electrical Steel

2011 ◽  
Vol 702-703 ◽  
pp. 738-741
Author(s):  
H. Qian ◽  
Ping Yang ◽  
G.H. Zheng ◽  
Wei Min Mao
Keyword(s):  
Hot Deformation ◽  
Grain Orientation ◽  
Electrical Steel ◽  
Compression Axis ◽  
Electrical Steels ◽  
Grain Orientations ◽  
Columnar Grains ◽  
Columnar Grain ◽  
The Relationship ◽  
Sample Axis

To identify the relationship between grain orientation and precipitation of MnS/AlN particles during hot deformation, cylinder samples containing columnar grains in electrical steels were prepared with different angles between columnar grain axis and sample axis. They were heated at 1360°C and compressed at 1100°C for 50%. Grain orientations and the precipitation states are determined using XRD, EBSD, EDS and SEM. Results indicate a general behavior of less precipitates in <100> and more precipitates in <111> grains. In addition, more precipitates were observed in samples with grain boundaries perpendicular to compression axis.

Estimation of Material Removal by Profilometer Measurements in Mass Finishing

2014 ◽  
Vol 611-612 ◽  
pp. 615-622
Author(s):  
Luana Bottini ◽  
Alberto Boschetto ◽  
Francesco Veniali
Keyword(s):  
Plastic Deformation ◽  
Surface Modification ◽  
Surface Morphology ◽  
Process Parameters ◽  
Material Removal ◽  
Machining Process ◽  
Local Surface ◽  
Mass Finishing ◽  
Barrel Finishing ◽  
The Relationship

This paper presents a new procedure to estimate the material removal (MR) in such conditions or operations where small amount of material or wear occur. The monitoring of material removal is essential to understand the machining mechanisms of several processes such as super finishing ones. For example the study of some mass finishing (MF) operations, i. e. the barrel finishing (BF) and the spindle finishing (SF), have been always limited by the difficulty to measure the local surface modification. Thus there is no knowledge about the relationship between process parameters and obtainable surface quality. The procedure is based on profilometer measurements typically used to characterized local surface morphology. An algorithm automatically finds the most representative peak of the profile. The comparison between the Abbot-Firestone curves, related to peaks achieved in different condition, permits to measure the volume of material removed by the operation. This method overcomes the well-known problem to repositioning the instrument in the same place when the part is moved from machining process to measurement one. In the case of BF, experimental demonstrated the reliability of this methodology to provide the evolution of material removed as a function of working time. Moreover the graphical plot of the representative peak at different times gave important information about machining mechanism. In particular it allowed to verify assumptions regarding the plastic deformation and the peak cutting which takes place.

On the Use of EBSD to Study the Heterogeneity of Plastic Deformation

2011 ◽  
Vol 702-703 ◽  
pp. 245-252 ◽  
Author(s):  
Francis Wagner ◽  
Nathalie Allain-Bonasso ◽  
Stephane Berbenni ◽  
David P. Field
Keyword(s):  
Plastic Deformation ◽  
Grain Orientation ◽  
If Steel ◽  
Geometrically Necessary Dislocation ◽  
Dislocation Densities ◽  
Before And After ◽  
Orientation Distributions ◽  
Grain Orientation Spread ◽  
Grain Size And Orientation

This paper deals with the study of plastic heterogeneity. It aims to study the role of both grain size and orientation distributions in the development of such heterogeneity. The considered material is an IF steel. EBSD maps have been made on the same areas before and after several degrees of extension. Parameters such as GOS (Grain Orientation Spread) or GOS/D (D the diameter of the grain) or GND (Geometrically Necessary Dislocation) densities have been determined for the whole set of grains as well as for subpopulations (smallest grains, largest grains for example). It appears that the character of neighboring grains plays a more important role than any of these parameters alone.

Stages of Plastic Deformation in Metallic Nanocrystals

2011 ◽  
Vol 683 ◽  
pp. 183-187 ◽  
Author(s):  
Nina Koneva ◽  
Eduard Kozlov
Keyword(s):  
Plastic Deformation ◽  
Work Hardening ◽  
Pure Copper ◽  
Paper Analysis ◽  
Deformation Localization ◽  
Tension And Compression ◽  
Average Size ◽  
20 Nm ◽  
First Time ◽  
The Relationship

In this paper, analysis of work hardening laws for grains with sizes on nano- and microlevel is carried out. The work is based on experimental data of deformation behavior of mainly pure copper at room temperature (RT). A special attention is given to the interval of grains with the average size between 20 nm and 230 nm. Work hardening stages of active plastic deformation during tension and compression are characterized. The dependence of work hardening coefficients on the average grains size at the nanoscale in the II, IV and VI stages is revealed for the first time. Mechanisms of deformation in the range of grains sizes between 10 nm and 1000 nm are categorized. The relationship between work hardening stages and deformation mechanisms is discussed. The stage of deformation where deformation localization takes place is determined.

Validation on the Relationship Between J Integral and CTOD for Offshore Structural Steel Weldments by Experimental and Numerical Analyses

2014 ◽  
Author(s):  
Dong Hyun Moon ◽  
Jeong Soo Lee ◽  
Jae Myung Lee ◽  
Myung Hyun Kim
Keyword(s):  
Plastic Deformation ◽  
Crack Tip ◽  
J Integral ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Constraint Factor ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Plastic Constraint ◽  
The Relationship

Elastic plastic fracture mechanics (EPFM) is the domain of fracture analysis which considers extensive plastic deformation at crack tip prior to fracture. J integral and crack tip opening displacement (CTOD) have been commonly used as parameters for EPFM analysis. The relationship between these parameters has been extensively studied by industry and academia. The plastic constraint factor can serve as a parameter to characterize constraint effects in fracture involving plastic deformation. Therefore, the characteristics of plastic constraint factor are important in EPFM analysis. In this study, the relationship between J Integral and CTOD was investigated by conducting fracture toughness tests using single edge notched bend (SENB) specimens. Also, plastic constraint factor was investigated by using finite element analysis. Numerical analysis was carried out using ABAQUS elastic-plastic analysis mode.

Studies of Microstructures and Properties of AZ91D Alloy Based on the Rheoforming Process

2015 ◽  
Vol 713-715 ◽  
pp. 2876-2879
Author(s):  
Xiao Ping Zheng ◽  
Ze Sheng Ji ◽  
Wei Wen Zhang ◽  
Ming Shao
Keyword(s):  
Mechanical Property ◽  
Plastic Deformation ◽  
Tensile Strength ◽  
Solid Fraction ◽  
Shape Factor ◽  
Holding Time ◽  
Az91d Alloy ◽  
Conventional Casting ◽  
Semi Solid ◽  
The Relationship

The semi-solid rheoforming process of AZ91D alloy with 9 % plastic deformation was investigated. The effect of holding time on the rheoforming formability of AZ91D alloy was analyzed. The relationship between holding time and microstructure, mechanical property was also researched. The results show that with increasing of holding time from 0 to 60 min at 575 °C, the filling distance increases firstly and then decreases, the solid fraction decreases firstly and then increases, the tensile strength and elongation are also increase firstly and then decrease. However, the increasing of holding time would lead to shape factor decreasing but particle coarsening. When holding time is 30 min, the solid fraction is lowest and the filling distance increases greatly. Compared to the conventional casting sample, the tensile strength and elongation of the rheoforming parts increase 43.9 % and 187.5 %, respectively.

On the Development of Grain-Orientation-Dependent and Inter-Phase Stresses in a Super Duplex Stainless Steel under Uniaxial Loading

2006 ◽  
Vol 524-525 ◽  
pp. 917-922 ◽  
Author(s):  
Ru Lin Peng ◽  
Yan Dong Wang ◽  
Guo Cai Chai ◽  
Nan Jia ◽  
Sten Johansson ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Stainless Steel ◽  
Neutron Diffraction ◽  
Grain Orientation ◽  
Super Duplex Stainless Steel ◽  
Lattice Strains ◽  
Duplex Steel ◽  
In Situ Neutron Diffraction ◽  
Phase Stresses

Microstresses due to intergranular and inter-phase interactions in an austenitic-ferritic super duplex steel (SAF 2507) under uniaxial compressive deformation have been studied by in-situ neutron diffraction experiments. Lattice strains of several hkl planes of austenite respective ferrite were mapped as a function of sample direction at a number of load levels during loading into the plastic regime and unloading. The analysis of the experimental results has shown that during loading both grain-orientation-dependent and inter-phase stresses were generated under plastic deformation that was inhomogeneous at the microstructural level. Residual stresses depending on the grain-orientation and phase have been found after unloading. The results also indicate stronger intergranular interactions among the studied hkl planes of austenite than those of ferrite.

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