Influence of Substrate on Cracking of Vapour-Deposited Thin Films Due to Residual Stresses

1989 ◽  
Vol 153 ◽  
Author(s):  
Robert M. Fisher ◽  
J.Z. Duan

AbstractThe influence of the substrate material on the column and grain microstructure, the residual stresses, crack patterns and delamination of Cr films has been investigated using TEM, SEM, and X-ray diffraction. The inter-influence of these factors which determine the long term reliability of microelectronics is discussed. When interfacial adhesion is very low, as may be the case with some polymer substrates, cracking occurs discontinuously during film formation each time the stress exceeds the critical value for fracture.

1989 ◽  
Vol 154 ◽  
Author(s):  
Robert M. Fisher ◽  
J.Z. Duan

AbstractThe influence of the substrate material on the column and grain microstructure, the residual stresses, crack patterns and delamination of Cr films has been investigated using TEM, SEM, and X-ray diffraction. The inter-influence of these factors which determine the long term reliability of microelectronics is discussed. When interfacial adhesion is very low, as may be the case with some polymer substrates, cracking occurs discontinuously during film formation each time the stress exceeds the critical value for fracture.


1999 ◽  
Vol 14 (12) ◽  
pp. 4521-4530 ◽  
Author(s):  
H. M. Hu ◽  
E. J. Lavernia ◽  
Z. H. Lee ◽  
D. R. White

The objective of this work was to investigate the fundamental factors that govern the formation and magnitude of residual stresses in A2 tool steel fabricated using spray-forming techniques. To that effect, a finite-element method (FEM) was performed by using a commercial code, ABAQUS, to solve for the temperature and displacement fields. Moreover, the residual stresses in the spray-formed materials were measured using x-ray diffraction to compare the FEM results with experimentation. Two types of substrate material, copper and Rescor™ 780 cer-cast ceramic, were used to investigate the influence of heat conduction on residual stress in the preforms. Relatively good agreement was found between experimentation and theory. The results show that the residual stress varies greatly with the position in deposited preform and that heat-transfer coefficient at the interface of spray-formed material/substrate affects the distribution and magnitude of the residual stresses significantly.


2021 ◽  
Vol 3 (12) ◽  
Author(s):  
Eckehard Mueller

Abstract There is frequent debate over the long-term stability of calibration specimens. It is an essential component of monitoring, especially for X-ray diffraction equipment used to determine residual stresses. If residual stresses are stable, a second consideration is that the residual stress should not be close to 0 MPa. If such specimens are available for monitoring, it is more sensitive concerning changes. These are key requirements when developing calibration specimens. In this study five specimens were observed, one of them was tested for more than 20 years. The stresses were determined with X-ray diffractometers. In the last four years two different X-ray methods for determination were used. It can be shown that high compressive residual stress does not change in steel if the specimens had no dynamic or static load and were stored under normal laboratory conditions. Article Highlights Finding a material in which compressive residual stress is stable Showing that the stability of compressive residual stress is over a long term The stability of the compressive residual stress is in a great range


Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1154
Author(s):  
Diego E. Lozano ◽  
George E. Totten ◽  
Yaneth Bedolla-Gil ◽  
Martha Guerrero-Mata ◽  
Marcel Carpio ◽  
...  

Automotive components manufacturers use the 5160 steel in leaf and coil springs. The industrial heat treatment process consists in austenitizing followed by the oil quenching and tempering process. Typically, compressive residual stresses are induced by shot peening on the surface of automotive springs to bestow compressive residual stresses that improve the fatigue resistance and increase the service life of the parts after heat treatment. In this work, a high-speed quenching was used to achieve compressive residual stresses on the surface of AISI/SAE 5160 steel samples by producing high thermal gradients and interrupting the cooling in order to generate a case-core microstructure. A special laboratory equipment was designed and built, which uses water as the quenching media in a high-speed water chamber. The severity of the cooling was characterized with embedded thermocouples to obtain the cooling curves at different depths from the surface. Samples were cooled for various times to produce different hardened case depths. The microstructure of specimens was observed with a scanning electron microscope (SEM). X-ray diffraction (XRD) was used to estimate the magnitude of residual stresses on the surface of the specimens. Compressive residual stresses at the surface and sub-surface of about −700 MPa were obtained.


2020 ◽  
Vol 9 (1) ◽  
pp. 998-1008
Author(s):  
Guo Li ◽  
Zheng Zhuang ◽  
Yajun Lv ◽  
Kejin Wang ◽  
David Hui

AbstractThree nano-CaCO3 (NC) replacement levels of 1, 2, and 3% (by weight of cement) were utilized in autoclaved concrete. The accelerated carbonation depth and Coulomb electric fluxes of the hardened concrete were tested periodically at the ages of 28, 90, 180, and 300 days. In addition, X-ray diffraction, thermogravimetry, and mercury intrusion porosimetry were also performed to study changes in the hydration products of cement and microscopic pore structure of concrete under autoclave curing. Results indicated that a suitable level of NC replacement exerts filling and accelerating effects, promotes the generation of cement hydration products, reduces porosity, and refines the micropores of autoclaved concrete. These effects substantially enhanced the carbonation and chloride resistance of the autoclaved concrete and endowed the material with resistances approaching or exceeding that of standard cured concrete. Among the three NC replacement ratios, the 3% NC replacement was the optimal dosage for improving the long-term carbonation and chloride resistance of concrete.


2006 ◽  
Vol 201 (7) ◽  
pp. 4372-4376 ◽  
Author(s):  
B. Girault ◽  
P. Villain ◽  
E. Le Bourhis ◽  
P. Goudeau ◽  
P.-O. Renault

2012 ◽  
Vol 490-495 ◽  
pp. 3486-3490
Author(s):  
Qiang Yu ◽  
Zhen Chen ◽  
Zhong Cheng Guo

In order to prepare a new type of anode material, stainless steel was selected as substrate material. The β-PbO2 coating on stainless steel substrate was prepared under the appropriate plating solution, and the PbO2-MnO2 coating was prepared with thermal decomposition. The crystal structure was determined by X-ray diffraction; Surface morphology was test by Scanning Electron Microscopy; the energy spectrum was used to determine element mass-fraction and the ratio of atomic number of the coatings.


1997 ◽  
Vol 485 ◽  
Author(s):  
Chih-hung Chang ◽  
Billy Stanbery ◽  
Augusto Morrone ◽  
Albert Davydov ◽  
Tim Anderson

AbstractCuInSe2 thin films have been synthesized from binary precursors by Rapid Thermal Processing (RTP) at a set-point temperature of 290°C for 70 s. With appropriate processing conditions no detrimental Cu2-xSe phase was detected in the CIS films. The novel binary precursor approach consisted of a bilayer structure of In-Se and Cu-Se compounds. This bilayer structure was deposited by migration enhanced physical vapor deposition at a low temperature (200°C) and the influence of deposition parameters on the precursor film composition was determined. The bilayer structure was then processed by RTP and characterized for constitution by X-ray diffraction and for composition by Wavelength Dispersive X-ray Spectroscopy.


2013 ◽  
Vol 772 ◽  
pp. 193-199 ◽  
Author(s):  
Carsten Ohms ◽  
Rene V. Martins

Bi-metallic piping welds are frequently used in light water nuclear reactors to connect ferritic steel pressure vessel nozzles to austenitic stainless steel primary cooling piping systems. An important aspect for the integrity of such welds is the presence of residual stresses. Measurement of these residual stresses presents a considerable challenge because of the component size and because of the material heterogeneity in the weld regions. The specimen investigated here was a thin slice cut from a full-scale bi-metallic piping weld mock-up. A similar mock-up had previously been investigated by neutron diffraction within a European research project called ADIMEW. However, at that time, due to the wall thickness of the pipe, stress and spatial resolution of the measurements were severely restricted. One aim of the present investigations by high energy synchrotron radiation and neutrons used on this thin slice was to determine whether such measurements would render a valid representation of the axial strains and stresses in the uncut large-scale structure. The advantage of the small specimen was, apart from the easier manipulation, the fact that measurement times facilitated a high density of measurements across large parts of the test piece in a reasonable time. Furthermore, the recording of complete diffraction patterns within the accessible diffraction angle range by synchrotron X-ray diffraction permitted mapping the texture variations. The strain and stress results obtained are presented and compared for the neutron and synchrotron X-ray diffraction measurements. A strong variation of the texture pole orientations is observed in the weld regions which could be attributed to individual weld torch passes. The effect of specimen rocking on the scatter of the diffraction data in the butt weld region is assessed during the neutron diffraction measurements.


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