Plastic and Elastic Behavior of Sputtered Bilayered Films by Nanoindedtation

1999 ◽  
Vol 594 ◽  
Author(s):  
N. Kikuchi ◽  
E. Kusano ◽  
Y. Sawahira ◽  
A. Kinbara
Keyword(s):  
Plastic Deformation ◽  
Elastic Modulus ◽  
Yield Stress ◽  
Sapphire Substrate ◽  
Elastic Energy ◽  
Deformation Behavior ◽  
Elastic Behavior ◽  
Dissipated Energy ◽  
Displacement Curve ◽  
Plastic Energy

AbstractDeformation behavior of sputtered Al/TiN and Cu/TiN bilayered films was examined by using dissipated and elastic energies estimated from the area enclosed by the load-displacement curve of nanoindentation. These films studied consisted of TiN top-layer of 500 nm and Al or Cu underlayer of 0 - 500 nm on glass or sapphire substrate. The dissipated energy for plastic deformation increased with increasing thickness of metal underlayer, while the elastic energy remained constant. A decrease in plastic energy was observed by changing the underlayer material from Al to Cu. Further, a reduction in elastic energy was observed when a sapphire was used as a substrate. Experimental results show that the plastic deformation mainly occurred in metal underlayer and the elastic deformation did in TiN layer and in the substrate. It was concluded that the yield stress and elastic modulus of layers and substrate strongly affect the deformation behavior of the films.

A study of indentation work in homogeneous materials

2006 ◽  
Vol 21 (6) ◽  
pp. 1363-1374 ◽  
Author(s):  
Mengxi Tan
Keyword(s):  
Plastic Deformation ◽  
Elastic Modulus ◽  
Elastic Energy ◽  
Size Effects ◽  
Unit Volume ◽  
Plastic Work ◽  
Total Work ◽  
Indentation Size ◽  
Scaling Relationships ◽  
Homogeneous Materials

The work of indentation is investigated experimentally in this article. A method of using the elastic energy to extract the elastic modulus is proposed and verified. Two types of hardness related to the work of indentation are defined and examined: Hwtis defined as the total work required creating a unit volume of contact deformationand Hwp is defined as the plastic work required creating a unit volume of plastic deformation; experiments show that both hardness definitions are good choices for characterizing hardness. Several features that may provide significant insights in understanding indentation measurements are studied. These features mainly concern some scaling relationships in indentation measurements and the indentation size effects.

scholarly journals Design and Implementation of Plastic Deformation Behavior by Cartesian Impedance Control Based on Maxwell Model

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Le Fu ◽  
Jie Zhao
Keyword(s):  
Plastic Deformation ◽  
Deformation Behavior ◽  
Robot Manipulator ◽  
Impedance Control ◽  
Maxwell Model ◽  
Physical Contact ◽  
Elastic Behavior ◽  
Plastic Deformation Behavior ◽  
In Series ◽  
Control Methodology

Compliance has become one prerequisite of robots designed to work in complex operation environment where dynamic and uncertain physical contact or impact takes place frequently and even intentionally. Impedance control is a typical complaint control methodology. Standard impedance control is based on dynamics described by a spring and damper model connected in parallel way, which endues the robot an elastic behavior. In contrast, plastic deformation can be realized by Maxwell model in which spring and damper connect in series. In this study, a novel Cartesian impedance controller is constructed based on the Maxwell model. Implementation in a robot manipulator is executed to validate and analyze the proposed control law. A plastic deformation behavior of the robot manipulator is produced and certain extent compliance is achieved under the unpredictable impact or contact force exerted by human or other environment objects.

Energy Evolution and Water Immersion-Induced Weakening Mechanism in the Sandstone Roof of Coal Mines

2021 ◽  
Author(s):  
Wenjie Liu ◽  
Ke Yang ◽  
Shuai Zhang ◽  
Zhainan Zhang ◽  
Rijie Xu
Keyword(s):  
Energy Storage ◽  
Water Content ◽  
Elastic Energy ◽  
Coal Mines ◽  
Energy Utilization ◽  
Dissipated Energy ◽  
Plastic Energy ◽  
Storage Limit ◽  
Energy Share ◽  
Number Of Cycles

Abstract The instability of underground spaces in abandoned coal mines with water-immersed rocks is one of the main hazards hindering the geothermal energy utilization and ecological restoration of post-mining areas. This study conducted graded cyclic loading-unloading tests of five groups of sandstone samples with different water contents. The evolution laws of input, elastic, dissipated, damping, and plastic energies were explored in detail, taking into account the damping effect. The normalized plastic energy was used to characterize the damage evolution of sandstone samples, which failure modes were analyzed from both macroscopic and microscopic perspectives. The X-ray diffraction technique and scanning electron microscopy were used to reveal the softening mechanism of sandstone's strength and elastic energy storage limit. The results showed that the graded cyclic loading's input, elastic, and dissipated energies increased gradually. The elastic energy share first increased and then stabilized, while dissipated energy share variation had the opposite trend. In each cycle, the input energy was primarily stored in the form of elastic energy, while the dissipated energy was mainly used to overcome the damping of sandstone. When the normalized number of cycles approached unity, the plastic energy share sharply increased, while that of the dampening energy featured an abrupt drop. Such change indicated an inevitable instability failure of the water-bearing sandstone. As the water content increased, the pore water exhibited more substantial lubrication, water-wedging, and dissolution effects on mineral particles. As a result, the latter obtained a round form, and the elastic energy storage limit of the sandstone decreased. When the water content was increased, the damage factor of sandstone after the same number of cycles increased at a relatively higher rate, and there was a transition of failure mode from brittle to ductile.

Microstructure and Plastic Deformation Behavior of Ni3V Single Crystals

2007 ◽  
Vol 561-565 ◽  
pp. 407-410 ◽  
Author(s):  
Koji Hagihara ◽  
Mayumi Mori ◽  
Yukichi Umakoshi
Keyword(s):  
Plastic Deformation ◽  
Single Crystals ◽  
Yield Stress ◽  
High Temperatures ◽  
Low Temperatures ◽  
Deformation Behavior ◽  
Plastic Deformation Behavior ◽  
Rapid Drop

Plastic deformation behavior of Ni3V with D022 structure was examined using the single crystals containing two dominant variants of three. At [557] loading orientation, {111}1/6<112] twinning is dominantly operative at low temperatures, but {111}1/2<112] slip is activated at high temperatures accompanied by a rapid drop of yield stress.

Microstructural Factors Affecting the Deformation Behavior of Mg12ZnY LPSO-Phase Alloys

2012 ◽  
Vol 706-709 ◽  
pp. 1158-1163 ◽  
Author(s):  
Koji Hagihara ◽  
Akihito Kinoshita ◽  
Yoshihiro Fukusumi ◽  
Michiaki Yamasaki ◽  
Yoshihito Kawamura
Keyword(s):  
Plastic Deformation ◽  
Yield Stress ◽  
Deformation Behavior ◽  
Basal Slip ◽  
The Other ◽  
Factors Affecting ◽  
Lpso Phase ◽  
Long Period ◽  
Other Hand

Microstructural factors that govern the plastic deformation of the long-period stacking ordered (LPSO) phase were clarified. The decrease in length of the long-axis for the plate-like shape of LPSO-phase grains increases the yield stress of the alloy in which basal slip is predominant in deformation. On the other hand, the yield stress tended to increase as the thickness of the plate-like shapes of the grains decreased for the alloy in which the formation of deformation kinks carried the strain.

Analysis of the spherical indentation cycle for elastic–perfectly plastic solids

2004 ◽  
Vol 19 (12) ◽  
pp. 3641-3653 ◽  
Author(s):  
L. Kogut ◽  
K. Komvopoulos
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Elastic Modulus ◽  
Yield Strength ◽  
Material Properties ◽  
Deformation Behavior ◽  
Plastic Material ◽  
Elastic Plastic ◽  
Loading And Unloading ◽  
Elastic Plastic Material

A finite element analysis of frictionless indentation of an elastic–plastic half-space by a rigid sphere is presented and the deformation behavior during loading and unloading is examined in terms of the interference and elastic–plastic material properties. The analysis yields dimensionless constitutive relationships for the normal load, contact area, and mean contact pressure during loading for a wide range of material properties and interference ranging from the inception of yielding to the initiation of fully plastic deformation. The boundaries between elastic, elastic–plastic, and fully plastic deformation regimes are determined in terms of the interference, mean contact pressure, and reduced elastic modulus-to-yield strength ratio. Relationships for the hardness and associated interference versus elastic–plastic material properties and truncated contact radius are introduced, and the shape of the plastic zone and maximum equivalent plastic strain are interpreted in light of finite element results. The unloading response is examined to evaluate the validity of basic assumptions in traditional indentation approaches used to measure the hardness and reduced elastic modulus of materials. It is shown that knowledge of the deformation behavior under both loading and unloading conditions is essential for accurate determination of the true hardness and reduced elastic modulus. An iterative approach for determining the reduced elastic modulus, yield strength, and hardness from indentation experiments and finite element solutions is proposed as an alternative to the traditional method.

Effect of the Pre-Strain on the Elastic Behavior of a Dual-Phase Steel with Different Martensite Contents

2021 ◽  
Vol 1016 ◽  
pp. 1555-1560
Author(s):  
Matthias Wallner ◽  
Reinhold Schneider ◽  
Katharina Steineder ◽  
Daniel Krizan ◽  
Thomas Hebesberger ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Elastic Modulus ◽  
Modulus Of Elasticity ◽  
Volume Fraction ◽  
Hardness Test ◽  
Martensite Phase ◽  
Elastic Behavior ◽  
Present Contribution ◽  
Martensite Volume Fraction ◽  
Dislocation Movement

The modulus of elasticity is an important parameter for an accurate prediction of the springback in sheet metal forming processes. With increasing plastic deformation, this modulus behaves nonlinearly and declines, which leads to an unpredictable springback behavior. The most cited reason for this nonlinearity is the dislocation movement during plastic deformation that especially occurs with multiphase steels. The present contribution investigates the nonlinear unloading behavior and the resulting decrease of the elastic modulus from a differently heat treated DP980 steel. The heat treatments set five different microstructures with martensite volume fractions in the range of 42 to 95 %. By means of the tensile test, a decline of the elastic modulus according to pre-strain was examined by evaluating the chord-modulus during unloading at different strain levels. In addition, a nano-hardness test was performed. It turned out that in all heat treatment conditions, a pronounced decrease in the modulus of elasticity up to 25% from the initial value occurred. With decreasing annealing temperature and lower martensite volume fraction, respectively, the martensite hardness increased, leading to higher hardness differences between the ferrite and the martensite phase in the microstructure. This led to an increase of strain hardening, i.e. to an increased formation of fresh mobile dislocations in the vicinity of the harder martensite phase during plastic deformation. As a result, the modulus of elasticity decreased more sharply. Thus, in the present contribution, an interplay between the martensite volume fraction and its hardness on the decrease of elastic modulus could be clearly manifested.

Plastic Deformation of Directionally-Solidified MoSi2/Mo5Si3 Eutectic Composites

2013 ◽  
Vol 1516 ◽  
pp. 195-200 ◽  
Author(s):  
Yuta Sasai ◽  
Atsushi Inoue ◽  
Kosuke Fujiwara ◽  
Kyosuke Kishida ◽  
Haruyuki Inui
Keyword(s):  
Plastic Deformation ◽  
Yield Stress ◽  
Deformation Behavior ◽  
Growth Direction ◽  
Average Thickness ◽  
Floating Zone ◽  
Directionally Solidified ◽  
Zone Method ◽  
Increasing Temperature ◽  
Loading Axis

ABSTRACTDeformation behavior of the directionally-solidified MoSi2/Mo5Si3 eutectic composites has been investigated as a function of the average thickness of MoSi2 phase over a temperature range from 900 to 1500°C. The average thickness of both MoSi2 and Mo5Si3 phases in the directionally-solidified ingots with script-lamellar morphologies grown by optical floating zone method decreases with increasing the growth rate. Plastic deformation was observed above 1000°C for all the DS ingots grown at different growth rates when the loading axis is parallel to [1¯10]MoSi2 close to the growth direction. Yield stress decreases monotonically with increasing temperature. Yield stress at 1400°C increases drastically with decreasing the average thickness of MoSi2 phase.

Microstructure and Deformation Behavior of Lamellar Ti-Rich TiAl Crystal with Lotus-Type Aligned Pores

2007 ◽  
Vol 561-565 ◽  
pp. 383-386 ◽  
Author(s):  
Takayoshi Nakano ◽  
Takahiro Tachibana ◽  
Koji Hagihara ◽  
Yukichi Umakoshi ◽  
Takuya Ide ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Yield Stress ◽  
Deformation Behavior ◽  
Lamellar Structure ◽  
Mixed Gas ◽  
Zone Method ◽  
Two Phase ◽  
Porous Ti ◽  
Plastic Deformation Behavior ◽  
Cylindrical Pores

A porous Ti-48.0at.%Al (Ti-rich TiAl) crystal, in which lotus-type long cylindrical pores were aligned and (γ/α2) two-phase lamellar structure was simultaneously developed, was fabricated by floating zone method under the pressure of hydrogen and helium mixed gas. Plastic deformation behavior and microstructure of the Ti-rich TiAl crystal with lotus-type aligned pores were investigated by focusing on the elongated pore direction. The as-grown and annealed crystals show a well-developed lamellar structure and no texture accompanied by 52% porosity and a mean pore diameter of 380 μm. Yield stress strongly depends on the loading direction against the elongated pore. When loading directions are parallel and perpendicular to the pore direction, yield stresses obey K=1 and 2.5, respectively, in equation of σ=σ0(1-p)K, where σ is the yield stress with pores, σ0 is the yield stress without pores and p is porosity. This reflects macroscopically homogeneous and locally heterogeneous plastic deformation between pores, respectively.

scholarly journals Investigation of Mechanical Properties and Plastic Deformation Behavior of (Ti45Cu40Zr10Ni5)100−xAlxMetallic Glasses by Nanoindentation

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Lanping Huang ◽  
Xuzhe Hu ◽  
TaoTao Guo ◽  
Song Li
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Elastic Modulus ◽  
Amorphous Alloy ◽  
Deformation Behavior ◽  
Alloy Composition ◽  
Loading Rate ◽  
Al Content ◽  
Plastic Deformation Behavior ◽  
Al Addition

The effect of Al addition on mechanical properties and plastic deformation behavior of (Ti45Cu40Zr10Ni5)100−xAlx(x= 0, 2, 4, 6 and 8) amorphous alloy ribbons have been investigated by nanoindentation. The hardness and elastic modulus do not simply increase with the increase of Al content. The alloy with 8 at.% Al exhibits the highest hardness and elastic modulus. The serrations or pop-in events are strongly dependent on the loading rate and alloy composition.

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