Prediction of residual stress components and their directions from pile-up morphology: An experimental study

2016 ◽  
Vol 31 (16) ◽  
pp. 2392-2397
Author(s):  
Lei Shen ◽  
Yuming He ◽  
Dabiao Liu ◽  
Meng Wang ◽  
Jian Lei
Keyword(s):  
Residual Stress ◽  
Experimental Study ◽  
Pile Up ◽  
Stress Components ◽  
Image Position

Abstract

A novel method for determining surface residual stress components and their directions in spherical indentation

2015 ◽  
Vol 30 (8) ◽  
pp. 1078-1089 ◽  
Author(s):  
Lei Shen ◽  
Yuming He ◽  
Dabiao Liu ◽  
Qiang Gong ◽  
Bo Zhang ◽  
...  
Keyword(s):  
Residual Stress ◽  
Spherical Indentation ◽  
Surface Residual Stress ◽  
Stress Components ◽  
Novel Method ◽  
Image Position

Abstract

Experimental Study on the Relationship between Dislocation Density and Internal Stress in Micro Electroforming Layer

2015 ◽  
Vol 645-646 ◽  
pp. 405-410 ◽  
Author(s):  
Chang Song ◽  
Li Qun Du ◽  
Tong Yang ◽  
Lei Luo ◽  
You Sheng Tao ◽  
...  
Keyword(s):  
Experimental Study ◽  
Dislocation Density ◽  
Internal Stress ◽  
Compressive Stress ◽  
Stress Relief ◽  
Ultrasonic Power ◽  
Pile Up ◽  
Ultrasonic Stress Relief ◽  
The Relationship ◽  
Dislocation Density Increase

In the micro electroforming process, the existence of electroforming layer defects caused by macro internal stress seriously limits the application and development of the micro electroforming technology. Currently, some studies have shown that ultrasonic can reduce the internal stress. But the formation process of the internal stress and the mechanism of ultrasonic stress relief in micro electroforming layer are still unclear now. In this paper, the relationship between dislocation density and internal stress under ultrasonic was studied. The results show that the ultrasonic can make the dislocation density increase and the compressive stress decrease. When the ultrasonic power is 200W, the dislocation density and the compressive stress culminate 3.8×10-15m-2 and-144.4MPa, respectively. The ultrasonic can excite the movement of dislocation proliferation, pile-up and opening, which leads to a micro plastic deformation in the crystal, and thereby releases the internal stress.

scholarly journals X-ray nanodiffraction analysis of stress oscillations in a W thin film on through-silicon via

2016 ◽  
Vol 49 (1) ◽  
pp. 182-187 ◽  
Author(s):  
J. Todt ◽  
H. Hammer ◽  
B. Sartory ◽  
M. Burghammer ◽  
J. Kraft ◽  
...  
Keyword(s):  
Thin Film ◽  
Residual Stress ◽  
Finite Element ◽  
Diffraction Data ◽  
Element Model ◽  
Stress Distributions ◽  
Through Silicon Via ◽  
X Ray ◽  
Tangential Stresses ◽  
Stress Components

Synchrotron X-ray nanodiffraction is used to analyse residual stress distributions in a 200 nm-thick W film deposited on the scalloped inner wall of a through-silicon via. The diffraction data are evaluated using a novel dedicated methodology which allows the quantification of axial and tangential stress components under the condition that radial stresses are negligible. The results reveal oscillatory axial stresses in the range of ∼445–885 MPa, with a distribution that correlates well with the scallop wavelength and morphology, as well as nearly constant tangential stresses of ∼800 MPa. The discrepancy with larger stress values obtained from a finite-element model, as well as from a blanket W film, is attributed to the morphology and microstructural nature of the W film in the via.

Extensive Experimental Study on Diaphragm-Based Piezoelectric Microphone

1999 ◽  
Author(s):  
Meng-Nian Niu ◽  
Hong Zeng ◽  
Hai Yan ◽  
Eun Sok Kim
Keyword(s):  
Residual Stress ◽  
Experimental Study ◽  
Acoustic Pressure ◽  
Structural Integrity ◽  
Vertical Displacement ◽  
Active Area ◽  
Zno Film ◽  
Beam Laser ◽  
Acoustic Chamber ◽  
Focused Beam

Abstract This paper reports our extensive experimental study on diaphragm-based piezoelectric microphones fabricated on a silicon substrate. We have fabricated and carefully analyzed about 60 micromachined piezoelectric microphones (composed of piezoelectric ZnO film, insulating layers and electrodes) built on a low-stress silicon nitride diaphragm (with and without corrugation on the diaphragm and with five kinds of residual stress in the diaphragm). Microphone sensitivity is measured in an acoustic chamber with a B&K4135 microphone. Vertical displacement of a microphone diaphragm under an applied acoustic pressure is measured with a focused-beam laser Doppler displacement meter. Our results show that (1) corrugation releases both tensile stress and compressive stress effectively, and increases the center displacement greatly, (2) a good bending curvature in the active area is needed for a good microphone sensitivity, and (3) ZnO structural integrity is the major factor that affects the bending curvature in the active area.

Experimental Study of Residual Stress Formation Mechanism of 7050 Aluminum Alloy Sheet by Laser Shock Processing

2016 ◽  
Vol 43 (7) ◽  
pp. 0702008
Author(s):  
曹宇鹏 Cao Yupeng ◽  
徐影 Xu Ying ◽  
冯爱新 Feng Aixin ◽  
花国然 Hua Guoran ◽  
周东呈 Zhou Dongcheng ◽  
...  
Keyword(s):  
Residual Stress ◽  
Experimental Study ◽  
Aluminum Alloy ◽  
Alloy Sheet ◽  
Laser Shock ◽  
Aluminum Alloy Sheet ◽  
Laser Shock Processing ◽  
7050 Aluminum Alloy ◽  
Stress Formation ◽  
Shock Processing

scholarly journals Experimental study on residual stress of milling medical magnesium alloy

2018 ◽  
Vol 397 ◽  
pp. 012046
Author(s):  
Yang Qiao ◽  
Peiquan Guo ◽  
Shouren Wang ◽  
Xuefeng Yang
Keyword(s):  
Residual Stress ◽  
Experimental Study ◽  
Magnesium Alloy

Dual-Axis Hole-Drilling ESPI Residual Stress Measurements

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Gary S. Schajer ◽  
Michael Steinzig
Keyword(s):  
Residual Stress ◽  
Measurement Errors ◽  
Measurement Method ◽  
Stress Measurement ◽  
Experimental Tests ◽  
Optical Data ◽  
Hole Drilling ◽  
Similar Response ◽  
Plane Normal ◽  
Stress Components

A novel dual-axis ESPI hole-drilling residual stress measurement method is presented. The method enables the evaluation of all the in-plane normal stress components with similar response to measurement errors, significantly lower than with single-axis measurements. A numerical method is described that takes advantage of, and compactly handles, the additional optical data that are available from the second measurement axis. Experimental tests were conducted on a calibrated specimen to demonstrate the proposed method, and the results supported theoretical expectations.

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