Thick Pb(Zr,Ti)O3 films fabricated by inducing residual compressive stress during the annealing process

2005 ◽  
Vol 20 (11) ◽  
pp. 2898-2901 ◽  
Author(s):  
Jae-Wung Lee ◽  
Jong-Jin Choi ◽  
Gun-Tae Park ◽  
Chee-Sung Park ◽  
Hyoun-Ee Kim
Keyword(s):  
Residual Stress ◽  
Electrical Properties ◽  
Compressive Stress ◽  
Crack Formation ◽  
Annealing Process ◽  
Residual Compressive Stress ◽  
Silicon Substrates ◽  
Si Substrate ◽  
Pzt Film ◽  
Pzt Films

The effects of residual stress induced during the annealing process on the microstructural evolution and electrical properties of Pb(Zr,Ti)O3 (PZT) films were investigated. PZT films were deposited on platinized silicon substrates by the radio frequency magnetron sputtering method using a single oxide target. Compressive stress was induced in the film by bending the silicon substrate during sputtering using a specially designed substrate holder and subsequently annealing the film without the holder. Without the residual stress, the PZT film was severely cracked when it was thicker than 2 μm due to the thermal expansion mismatch between the PZT and the Si substrate. On the other hand, when the residual stress was applied, no cracks were detected in the film for thicknesses of up to 4 μm. The suppression of crack formation was attributed to the residual compressive stress that compensated for the tensile stress generated during and/or after the annealing process. The electrical properties of the PZT film with the residual stress were improved compared to those of the PZT film without the residual stress.

Effect on Crystal Orientation on Residual Stress and Electrical Properties of a PZT Thin Film Deposited on Buffered-Si Substrate

2006 ◽  
Vol 320 ◽  
pp. 65-68
Author(s):  
Keisuke Fujito ◽  
Naoki Wakiya ◽  
Takanori Kiguchi ◽  
Nobuyasu Mizutani ◽  
Kazuo Shinozaki
Keyword(s):  
Thin Films ◽  
Residual Stress ◽  
Electrical Properties ◽  
Tensile Stress ◽  
Remanent Polarization ◽  
Residual Tensile Stress ◽  
Si Substrate ◽  
Pzt Thin Films ◽  
Pzt Film ◽  
Pzt Thin Film

Changes of residual stress and electrical properties were examined in (001)-oriented and (111)-oriented Pb(Zr0.5Ti0.5)O3 (PZT) thin films deposited on a buffered-Si substrate with a buffer and bottom electrode layer of a (La,Sr)CoO3(LSCO). A (001)-epitaxial PZT film was prepared on LSCO/CeO2 /Zr0.85Y0.15O1.93(YSZ)/Si. In addition, a (111)-oriented PZT film was prepared on LSCO/SrTiO3(ST) /Mn0.24Zn0.09Fe2.67O4(MZF)/YSZ/Si. The residual tensile stress in (001)-PZT thin films decreased from 2.92 to 1.98 GPa and the remanent polarization increased from 7.5 to 41.7 @C/cm2 as the LSCO thickness increased. In (111)-PZT, the residual tensile stress decreased from 1.72 to 0.95 GPa and remanent polarization increased from 9.5 to 26.7 @C/cm2. The residual tensile stress of (111)-PZT was less than that of (001)-PZT. The remanent polarization in the 80 nm (111)-PZT was greater than that of the 60 nm (001)-PZT. In the 700-nm-thick PZT, the remanent polarization in (001)-PZT was greater than that in (111)-PZT.

Effect of 7050 Aluminium Alloy Microstructure on Residual Stress by Laser Shock Processing

2012 ◽  
Vol 463-464 ◽  
pp. 1363-1367
Author(s):  
M.L. Zhang ◽  
J.M. Wang ◽  
Y.F. Jiang ◽  
Q.L. Zhang ◽  
Q.L. Zhou
Keyword(s):  
Residual Stress ◽  
Aluminium Alloy ◽  
Compressive Stress ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Residual Compressive Stress ◽  
Original Structure ◽  
Laser Shock ◽  
Laser Shock Processing ◽  
Shock Processing

The solution treatment and solution and aging treatment (T6) were disposed on 7050 aluminium alloy, then local processed by laser shock processing (LSP) with high-rate neodymium glass laser. The microhardness and residual stress on the surface of 7050 aluminium alloy were tested, then how the microstructure influences the residual stress on the surface of 7050 aluminium alloy by laser shock processing was analysed. The results show that the microhardness and residual compressive stress on the surface of 7050 aluminium alloy treated by solution and aging treatment was higher, and decreased obviously treated by solution treatment; the microhardness and residual compressive stress on the surface of 7050 aluminium alloy increased obviously by solution treatment and solution and aging treatment after laser shock processing; treated by solution treatment and solution and aging treatment, the microhardness and residual compressive stress of the material with uniform original structure was higher than the material with nonuniform original structure.

Numerical simulation of the effect of ultrasonic impact treatment on welding residual stress

2021 ◽  
pp. 2150175
Author(s):  
Tao Mo ◽  
Jingqing Chen ◽  
Pengju Zhang ◽  
Wenqian Bai ◽  
Xiao Mu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Compressive Stress ◽  
Welded Joints ◽  
Welding Process ◽  
Residual Compressive Stress ◽  
Welding Residual Stress ◽  
304 Stainless Steel ◽  
Residual Tensile Stress ◽  
Ultrasonic Impact Treatment

Ultrasonic impact treatment (UIT) is an effective method that has been widely applied in welding structure to improve the fatigue properties of materials. It combines mechanical impact and ultrasonic vibration to produce plastic deformation on the weld joints surface, which introduces beneficial compressive residual stress distribution. To evaluate the effect of UIT technology on alleviating the residual stress of welded joints, a novel numerical analysis method based on the inherent strain theory is proposed to simulate the stress superposition of welding and subsequent UIT process of 304 stainless steel. Meanwhile, the experiment according to the process was carried out to verify the simulation of residual stress values before and after UIT. By the results, optimization of UIT application could effectively reduce the residual stress concentration after welding process. Residual tensile stress of welded joints after UIT is transformed into residual compressive stress. UIT formed a residual compressive stress layer with a thickness of about 0.13 mm on the plate. The numerical simulation results are consistent with the experimental results. The work in this paper could provide theoretical basis and technical support for the reasonable evaluation of the ultrasonic impact on residual stress elimination and mechanical properties improvement of welded joints.

PZT Thin Films on Silicon Substrates: Formation and Research of Properties

2020 ◽  
Vol 28 ◽  
pp. 65-70 ◽  
Author(s):  
Victor V. Petrov ◽  
Yuriy N. Varzarev ◽  
Anton S. Kamentsev ◽  
Andrey A. Rozhko ◽  
Oksana A. Pakhomova
Keyword(s):  
Lead Zirconate Titanate ◽  
Test Bench ◽  
Surface States ◽  
Lead Zirconate ◽  
Silicon Substrates ◽  
Ferroelectric Films ◽  
Pzt Film ◽  
Structure Morphology ◽  
Pzt Films ◽  
Electrophysical Parameters

In this paper, we consider the technological features of the formation of thin ferroelectric films of lead zirconate titanate (PZT) by the method of plasma high-frequency reactive sputtering. The crystal structure, morphology and elemental composition of films deposited on silicon and oxidized silicon substrates are investigated. It is shown that the obtained PZT films have a perovskite structure and are polycrystalline with a predominant crystallite growth in the (110) direction. An automated test bench has been designed and manufactured for measuring the electrophysical parameters of ferroelectric films. The measured CV characteristics of the Ni/PZT/Si structure show the hysteresis caused by the polarization of the PZT film. It is noted that the asymmetry of the dependence of the spontaneous polarization on the applied voltage can be caused by the presence of surface states at the PZT/Si interface.

scholarly journals Investigation on Residual Stress Loss during Laser Peen Texturing of 316L Stainless Steel

2019 ◽  
Vol 9 (17) ◽  
pp. 3511 ◽  
Author(s):  
Kangmei Li ◽  
Yifei Wang ◽  
Yu Cai ◽  
Jun Hu
Keyword(s):  
Residual Stress ◽  
Compressive Stress ◽  
Power Density ◽  
Laser Power ◽  
Surface Deformation ◽  
Laser Power Density ◽  
Residual Compressive Stress ◽  
Laser Spot ◽  
Residual Tensile Stress ◽  
Spot Radius

Laser peen texturing (LPT) is a novelty way of surface texturing based on laser shock processing. One of the most important benefits of LPT is that it can not only fabricate surface textures but also induce residual compressive stress for the target material. However, the residual stress loss leads to partial loss of residual compressive stress and even causes residual tensile stress at the laser spot center. This phenomenon is not conducive to improving the mechanical properties of materials. In this study, a numerical simulation model of LPT was developed and validated by comparison of surface deformation with experiments. In order to investigate the phenomenon of residual stress loss quantitatively, an evaluation method of residual stress field was proposed. The effects of laser power density and laser spot radius on the residual stress, especially the residual stress loss, were systematically investigated. It is found that with the increase of laser power density or laser spot radius, the thickness of residual compressive layer in depth direction becomes larger. However, both the magnitude and the affecting zone size of residual stress loss will be increased, which implies a more severe residual stress loss phenomenon.

Study on Pre-Stress Cutting of Bearing Race and Its Machined Surface State

2006 ◽  
Vol 532-533 ◽  
pp. 528-531 ◽  
Author(s):  
Bang Yan Ye ◽  
Bo Wu ◽  
Jian Ping Liu ◽  
Xiao Chu Liu ◽  
Xue Zhi Zhao
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Compressive Stress ◽  
Contact Fatigue ◽  
Residual Compressive Stress ◽  
Residual Tensile Stress ◽  
Machined Surface ◽  
Residual Stress State ◽  
Bearing Race ◽  
Hard Cutting

Theoretical analysis and experiments on bearing race show that a suitable residual compressive stress on roll path of bearing race can prolong its contact fatigue life. However, residual tensile stress is often found on workpiece surface of bearing race. To actively control the residual stress state and improve fatigue life of bearing part, a new method of pre-stress hard cutting is applied. In this paper, the principle of pre-stress hard cutting for bearing race is introduced as well as the experiments on it. In the experiments, residual stress, hardness and roughness of machined surface are measured and analyzed. Moreover, micro-topography and texture characteristics of machined surface are investigated and experimental results are compared with that by grinding. It is found that we can get residual compressive stress and fine quality on machined surface of bearing race by pre-stress hard cutting and increase its productivity as well.

Effect of residual stress and microstructure on corrosion resistance of carburised 18CrNiMo7-6 steel

2020 ◽  
Vol 67 (4) ◽  
pp. 357-366
Author(s):  
Gang Wang ◽  
Yue Zhang ◽  
Chen Gao ◽  
GuangTao Xu ◽  
MingHao Zhao
Keyword(s):  
Aqueous Solution ◽  
Residual Stress ◽  
Compressive Stress ◽  
High Speed ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Electrochemical Potential ◽  
Residual Compressive Stress ◽  
Content Type ◽  
Electrochemical Tests

Purpose The purpose of this paper is to investigate, the effects of residual stress and microstructure on the corrosion behaviour of carburised 18CrNiMo7-6 steel in a 3.5% NaCl aqueous solution. Design/methodology/approach The electrochemical tests were conducted using an electrochemical workstation with a three-electrode system in a 3.5% NaCl aqueous solution, the residual stress of each working face was measured by a high-speed residual stress analyser, and microstructure of different carburised layers were observed scanning electron microscopy. Finally, the effect of carbon content, microstructure and residual stress on the corrosion behaviour of the steel was discussed. Findings The results showed that the residual compressive stress in the carburised layer initially increased and subsequently decreased with increasing depth of the carburised layer, reaching stability in the matrix layer. The electrochemical tests before and after stress reduction showed that the electrochemical impedance and the electrochemical potential increased with the reduction of residual compressive stress. Originality/value The residual compressive stress in the carburised layer initially increases and subsequently decreases with increasing carburised layer depth. The electrochemical impedance and the electrochemical potential increased with the reduction of residual compressive stress. The general relationship between electrochemical potential and residual stress was established.

The Influence of the Post-Annealing Temperature on the Crystalline Orientation and the Crystallinity of PZT Films

2012 ◽  
Vol 490-495 ◽  
pp. 3845-3849
Author(s):  
Jing Wan ◽  
Cheng Tao Yang ◽  
Yang Gao
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Annealing Process ◽  
Process Conditions ◽  
X Ray Diffraction ◽  
Rapid Thermal Annealing Process ◽  
Pzt Film ◽  
Pzt Films ◽  
Thermal Annealing Process ◽  
Nucleation And Growth Mechanism

In this article, based on nucleation and growth mechanism of films, different process conditions of rapid thermal annealing (RTA) had been investigated to attain different orientation and the crystallinity of PZT film. At first, the PZT films had been fabricated by magnetron sputtering on Si/SiO2/Ti/Pt substrates, then crystallized by different stepped rapid thermal annealing process. X-ray diffraction (XRD) was used to analyze the crystal structures of the films and scanning electron microscope (SEM) was used to analyze the surface morphology of the films. As a conclusion about the research is that it is good for controlling the crystallographic orientation and enhancing the crystallinity of PZT film by different stepped rapid thermal annealing process

Effects of Residual Stress on the Electrical Properties of PZT Films

2007 ◽  
Vol 90 (4) ◽  
pp. 1077-1080 ◽  
Author(s):  
Jae-Wung Lee ◽  
Chee-Sung Park ◽  
Miyoung Kim ◽  
Hyoun-Ee Kim
Keyword(s):  
Residual Stress ◽  
Electrical Properties ◽  
Pzt Films
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