Mechanical Properties and Microstructure of AL(1wt%SI) And AL(1wt%SI, 0.5wt%CU) Thin Films. The Role of Diffusional Creep in the Tensile Stress Regime

1994 ◽  
Vol 356 ◽  
Author(s):  
S. Bader ◽  
E. M. Kalaugher ◽  
E. Arzt
Keyword(s):  
Mechanical Properties ◽  
Relaxation Mechanism ◽  
Diffusional Creep ◽  
Stress Regime ◽  
Cu Films ◽  
Dislocation Glide ◽  
Transmission Electron ◽  
Diffusional Relaxation ◽  
Coble Creep

AbstractThe microstructure and mechanical properties of hot (h) and cold (c) sputtered Al-lwt%Si and Al-lwt%Si-0.5wt%Cu films were studied using transmission electron microscopy and wafer curvature stress measurements.Stress/temperature curves of all films showed only slight differences in compression on healing once a stable grain size was established. However, on cooling several remarkable differences were observed. These observations cannot be explained by assuming dislocation glide/climb as the dominant relaxation mechanism. The results will be discussed in terms of grain boundary diffusional relaxation (Coble creep), which occurs in addition to dislocation glide.

Influence of a Capping Layer on the Mechanical Properties of Copper Films

1994 ◽  
Vol 356 ◽  
Author(s):  
R.-M. Keller ◽  
S. Bader ◽  
R. P. Vinci ◽  
E. Arzt
Keyword(s):  
Mechanical Properties ◽  
Film Thickness ◽  
Grain Growth ◽  
Low Temperatures ◽  
Bauschinger Effect ◽  
Diffusional Creep ◽  
Copper Films ◽  
Cu Films ◽  
Heating And Cooling ◽  
Cooling Stress

AbstractThe substrate curvature technique was employed to study the mechanical properties of 0.6 μm and 1.0 μm Cu films capped with a 50 nm thick Si3N4 layer and to compare them with the mechanical properties of uncapped Cu films. The microstructures of these films were also investigated. Grain growth, diffusional creep and dislocation processes are impeded by the cap layer. This is evident in the form of high stresses at high temperatures on heating and at low temperatures on cooling. At intermediate temperatures on heating and cooling, stress plateaus a relatively low stresses exist. This can be explained by the so-called Bauschinger effect. A film thickness dependence of the stresses in the film could not be observed for capped Cu films.

scholarly journals Temperature dependence of mechanical properties in ultrathin Au films with and without passivation

2008 ◽  
Vol 23 (9) ◽  
pp. 2406-2419 ◽  
Author(s):  
Patric A. Gruber ◽  
Sven Olliges ◽  
Eduard Arzt ◽  
Ralph Spolenak
Keyword(s):  
Mechanical Properties ◽  
Temperature Dependence ◽  
Elevated Temperatures ◽  
Bulk Material ◽  
Diffusional Creep ◽  
Strong Temperature Dependence ◽  
Metallic Films ◽  
Dislocation Glide ◽  
Thermally Activated ◽  
Passivation Layers

Temperature and film thickness are expected to have an influence on the mechanical properties of thin films. However, mechanical testing of ultrathin metallic films at elevated temperatures is difficult, and few experiments have been conducted to date. Here, we present a systematic study of the mechanical properties of 80–500-nm-thick polycrystalline Au films with and without SiNx passivation layers in the temperature range from 123 to 473 K. The films were tested by a novel synchrotron-based tensile testing technique. Pure Au films showed strong temperature dependence above 373 K, which may be explained by diffusional creep. In contrast, passivated samples appeared to deform by thermally activated dislocation glide. The observed activation energies for both mechanisms are considerably lower than those for the bulk material, indicating that concomitant stress relaxation mechanisms are more pronounced in the thin film geometry.

Dynamic Mechanical Properties and Thermal Stability of PTT/POE/OMMT Nanocomposites

2011 ◽  
Vol 366 ◽  
pp. 306-309
Author(s):  
Ming Tao Run ◽  
Na Li ◽  
Bing Tao Xing ◽  
Meng Yao ◽  
Wen Zhou
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Dynamic Mechanical Properties ◽  
Thermal Gravimetric ◽  
Dynamic Mechanical ◽  
Thermal Gravimetric Analyzer ◽  
Transmission Electron ◽  
Reinforcing Agent ◽  
Thermal Stability Of

The dynamic mechanical properties, phase morphology and thermal stability of the poly(trimethylene terephthalate)/maleinized poly(octene-ethylene)/organo-montmorillonite nanocomposites (PTT/POE/OMMT) were investigated by using the thermodynamic mechanical analyzer (DMA), transmission electron microscopy (TEM) and thermal gravimetric analyzer (TGA), respectively. The results suggest that the modulus of elasticity of the PTT/POE/OMMT nanocomposite increases, and the glass transition temperature first slightly decreases and then increases with increasing OMMT content because that the TPP plays the role of plasticizer and OMMT plays the role of reinforcing agent. OMMT disperse evenly in the polymer matrix with most of the strip-like sheet morphology. The addition of the OMMT does not apparently affect the thermal stability of the PTT/POE/OMMT nanocomposite.

Synthesis of a Core-Shell Acrylate Elastomer with UV Stabilization and its Application in Polyoxymethylene

2011 ◽  
Vol 239-242 ◽  
pp. 2431-2434 ◽  
Author(s):  
Fan Yang ◽  
Gui Bo Wu ◽  
Shi Ling Zhang ◽  
Xian Cheng Ren
Keyword(s):  
Mechanical Properties ◽  
Methyl Methacrylate ◽  
Uv Irradiation ◽  
Butyl Acrylate ◽  
Core Shell ◽  
Visible Absorption ◽  
Transmission Electron ◽  
Before And After ◽  
Uv Stabilization

In this study, a core-shell structure acrylate elastomer with UV stabilization core–shell poly[methyl methacrylate-butyl acrylate-2-hydroxy-4-(3-methacryloxy-2-hydroxylproroxy) benzophenone] [poly(MMA-BA-BPMA)] was synthesized by methyl methacrylate (MMA), butyl acrylate (BA) and a polymerizable UV-stabilizer 2-hydroxy-4-(3-methacryloxy-2-hydroxylproroxy) benzophenone (BPMA) via semicontinuous seeding emulsion polymerization. The composition and characteristics of core-shell Poly (MMA-BA-BPMA) were determined by using Fourier transform infrared spectroscopy (FTIR), Ultraviolet-visible absorption spectroscopy (UV-vis) and transmission electron microscope (TEM). Further, the obtained core-shell poly (MMA-BA-BPMA) was blended with polyoxymethylene (POM) to modify its photostabilization. The mechanical properties of POM composite were tested before and after UV-irradiation. The result showed that core-shell poly (MMA-BA-BPMA) can be dispersed well in the POM matrix, which could play a role of improving compatibility with POM and the mechanical properties of modified POM were kept well, which leaded higher impact strength and elongation at break after UV-irradiation.

Tailoring Grain-Boundary Segregation to Control Mechanical Properties

1999 ◽  
Vol 586 ◽  
Author(s):  
D. B. Williams ◽  
V. J. Keast
Keyword(s):  
Mechanical Properties ◽  
Grain Boundary ◽  
Boundary Segregation ◽  
X Ray ◽  
Transmission Electron ◽  
Intergranular Brittle Fracture ◽  
Properties Of Materials ◽  
Boundary Chemistry ◽  
First Time

ABSTRACTRecent advances in our understanding of the role of the chemistry of grain boundaries in controlling the mechanical properties of materials (in particular intergranular brittle fracture) are reviewed. It is now possible in a modem field-emission gun (FEG) analytical transmission electron microscope (AEM) to measure the chemistry of sub-nanometer films of GB segregants while at the same time observing the effect (if any) on the bonding of the atoms within a nanometer of the boundary plane. This has been accomplished by the development of X-ray mapping (XRM) a powerful new tool for the study of segregation. For the first time, in the same instrument, on the same grain boundary, any changes in the boundary chemistry can be correlated with the occurrence or absence of brittle failure, which is often associated with boundary segregation. There is strong evidence that boundary segregation is extremely nonuniform, even in some strongly embrittling systems (e.g. Cu-Bi) and in these same systems, embrittling segregants introduce subtle but consistent changes in the bonding. Non-embrittling segregants (e.g. Ag in Cu) do not introduce detectable bonding changes.

Stress Relaxation in Al–Cu and Al–Si–Cu Thin Films

1999 ◽  
Vol 14 (4) ◽  
pp. 1246-1254 ◽  
Author(s):  
A. Witvrouw ◽  
J. Proost ◽  
Ph. Roussel ◽  
P. Cosemans ◽  
K. Maex
Keyword(s):  
Stress Relaxation ◽  
Thermal Cycling ◽  
Thermal Cycle ◽  
Room Temperature ◽  
Relaxation Data ◽  
Cu Films ◽  
Dislocation Glide ◽  
Transmission Electron ◽  
Stress Changes ◽  
Curvature Measurements

Substrate curvature measurements were used to study stress changes during thermal cycling and isothermal tensile stress relaxation in 800 nm Al–0.5 wt% Cu and Al–1 wt% Si–0.5 wt% Cu films. For both compositions dislocation glide can describe the relaxation data well for temperatures up to 120 °C for Al–Si–Cu and up to 100 °C for Al–Cu. The average activation energy for Al–Si–Cu and Al–Cu is 1.7 ± 0.2 eV and 3.0 ± 0.3 eV, respectively. The athermal flow stress is the same for both and equal to 600 ± 200 MPa. This result is consistent with the obstacles for glide being Al2Cu precipitates, which, in the case of Al–Si–Cu, are fine and can be cut by the dislocations, and, in the case of Al–Cu, are strong and provide Orowan strengthening. Also, the stress changes during thermal cycling in the Al–Cu films are different from those in the Al–Si–Cu films. For Al–Cu films, the room temperature stress decreases after each thermal cycle, while for Al–Si–Cu stress changes during thermal cycling are stable from the second cycle on. These observations are supported by thorough transmission electron microscopy (TEM) studies.

The Mechanical Properties of a Novel Si3N4-Amorphous Si3N4 Composite

1992 ◽  
Vol 287 ◽  
Author(s):  
Ivar E. Reimanis ◽  
J. J. Petrovic ◽  
H. Suematsu ◽  
T. E. Mitchell ◽  
O. S. Leung
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Heat Treating ◽  
Two Phase ◽  
Transmission Electron ◽  
Amorphous Si ◽  
The Relationship ◽  
Amorphous Si3n4

ABSTRACTThe hardness and fracture toughness of a model two-phase composite consisting of crystalline Si3N4 particles in a matrix of amorphous Si3N4 are examined. The composite is created by heat treating high purity, partially amorphous CVD Si3N4 in N2 for various times and temperatures in order to induce crystallization of the a phase. Microindentation tests at temperatures up to 1200 °C are conducted to evaluate the high temperature hardness and fracture toughness. The role of the microstructure is examined using optical and transmission electron microscopy. Finally, the relationship between the microstructure and the mechanical properties is discussed.

Effect of Polymerizable Surfactant Modified Clay on the Morpholorgy and Flexural Properties of Diallyl Phthalate/Clay Nanocomposites

2012 ◽  
Vol 486 ◽  
pp. 243-246
Author(s):  
Zhen Xing Kong ◽  
Gui Ying Li ◽  
Zi Lin Dai
Keyword(s):  
Mechanical Properties ◽  
Flexural Properties ◽  
Clay Nanocomposites ◽  
Pendant Group ◽  
High Magnification ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Diallyl Phthalate

The objective of this study is to examine the role of polymerizable and unpolymerizable pendant group of surfactant in clay dispersion in diallyl phthalate (DAP) matrix and evaluate the mechanical properties of resulting nanocomposites. Results of X-ray Diffraction (XRD) and high magnification Transmission Electron Microscopy (TEM) indicate an intercalated morphology for both types of nanocomposites, while low magnification TEM results show better dispersion of clay tactoids in the nanocomposite formulated with organclay containing polymerizable terminal pendant group. The mechanical properties of nanocomposites with organoclay loading of 1, 3, 5 and 7 wt%, respectively, were determined by performing flexural measurements. The testing results show that the nanocomposite formulated with organclay containing polymerizable terminal pendant group has better flexural properties than that formulated with organoclay containing unpolymerizable pendant group.

A New Type of Dislocation Mechanism in Ultrathin Copper Films

2001 ◽  
Vol 695 ◽  
Author(s):  
T. John Balk ◽  
Gerhard Dehm ◽  
Eduard Arzt
Keyword(s):  
Film Surface ◽  
Dislocation Motion ◽  
Diffusional Creep ◽  
Copper Films ◽  
Dislocation Mechanism ◽  
Plan View ◽  
Dislocation Glide ◽  
Transmission Electron ◽  
New Type

ABSTRACTIn this study of thin film plasticity, the relationship between thermomechanical behavior and dislocation motion has been investigated in copper constrained by a silicon substrate. The stress-temperature behavior as determined from wafer curvature experiments has been directly compared to deformation microstructures observed during in situ thermal cycling of plan-view specimens in the transmission electron microscope. The flow stress of copper films with thicknesses ranging from 100 nm to 400 nm was found to be constant, indicating that strengthening mechanisms may be saturated in this thickness regime. Moreover, unexpected dislocation glide on a plane parallel to the film surface, which should experience no resolved shear stress, provides potential evidence for the occurrence of constrained diffusional creep in a 270 nm film.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

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