scholarly journals Understanding and Tailoring the Mechanical Properties of Liga Fabricated Materials

1998 ◽  
Vol 546 ◽  
Author(s):  
T. E Buchheit ◽  
T. R. Christenson ◽  
D. T. Schmale ◽  
D. A. Lavan
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Anisotropic Material ◽  
Mechanical Test ◽  
Plating Bath ◽  
Plane Anisotropy ◽  
Out Of Plane ◽  
Microstructural Morphology ◽  
Test Frame ◽  
Deposition Conditions

AbstractLIGA fabricated materials and components exhibit several processing issues affecting their metallurgical and mechanical properties, potentially limiting their usefulness for MEMS applications. For example, LIGA processing by metal electrodeposition is very sensitive to deposition conditions which causes significant processing lot variations of mechanical and metallurgical properties. Furthermore, the process produces a material with a highly textured lenticular microstructural morphology suggesting an anisotropic material response. Understanding and controlling out-of-plane anisotropy is desirable for LIGA components designed for out-of-plane flexures. Previous work by the current authors [6] focussed on results from a miniature servo-hydraulic mechanical test frame constructed for characterizing LIGA materials. Those results demonstrated microstructural and mechanical properties dependencies with plating bath current density in LIGA fabricated nickel (LIGA Ni). This presentation builds on that work and fosters a methodology for controlling the properties of LIGA fabricated materials through processing. New results include measurement of mechanical properties of LIGA fabricated copper (LIGA Cu), out-of-planeand localized mechanical property measurements using compression testing and nanoindentation of LIGA Ni and LIGA Cu.

Out-of-Plane Mechanical Property Test on Titanium Honeycomb Cores

2013 ◽  
Vol 718-720 ◽  
pp. 1018-1023
Author(s):  
Zong Hong Xie ◽  
Xiao Yu Liu ◽  
Xi Shan Yue ◽  
Qun Yan ◽  
Jun Feng Sun ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Test ◽  
Solid Model ◽  
Honeycomb Core ◽  
Plane Shear ◽  
Cellular Solid ◽  
Homogeneity Assumption ◽  
Out Of Plane ◽  
Honeycomb Cores ◽  
Orthotropic Behavior

As a typical cellular solid, the honeycomb core shows an orthotropic behavior in its mechanical properties. Engineering analysis often adopts a homogeneity assumption that honeycomb core is equivalent to an anisotropic continuum. Currently available cellular solid model cannot predict the physical properties of titanium honeycomb core with acceptable accuracy. Therefore, mechanical test must be carried out to obtain the mechanical properties of metallic honeycomb structures. This paper introduces the work on flatwise compression test and out-of-plane shear test on titanium honeycomb core structures in accordance to ASTM C 365-03and ASTM C 273-00. The out-of-plane stiffness and strength for titanium honeycomb cores with incircle diameter of 4.8mm and wall thickness of 0.05mm were obtained.

scholarly journals Development of a Transparent Indenter Measurement System and Indentation Analysis for Material Mechanical Property Evaluation

2005 ◽  
Author(s):  
Bruce S. Kang ◽  
Chuanyu Feng
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Surface Deformation ◽  
Plane Deformation ◽  
Contact Radius ◽  
Spherical Indentation ◽  
Stress Strain ◽  
Out Of Plane ◽  
Transparent Indenter

Since Tabor showed the application of spherical indentation approach to obtain material post-yielding true stress-strain curves, the indentation technique has been investigated to determine mechanical properties besides hardness measurement. Accurate measurement of indentation parameters is critical in the determination of surface mechanical properties using indentation method. In this research, an in-situ optical Transparent Indenter Measurement (TIM) method was developed for material inspection and mechanical property measurement. Using spherical indentation, residual surface deformation after spherical indentations was first investigated on IN783 superalloy samples using phase-shifting Twyman-Green and moire´ interferometry. The elastic-plastic boundary was identified based on the characteristic of the out-of-plane deformation fringe patterns. Then using the measured in-plane deformation, yield strength of the tested material was obtained. Using the TIM system, real-time in-situ measurement of indentation-induced out-of-plane deformation and contact radius were directly measured during an indentation process. Coupled with elastic recovery theories and 2D finite element analyses, a procedure was developed to determine the material stress-strain curve. It is also demonstrated that the TIM method is suitable for debonding inspection of thin film materials.

Investigation of The Mechanical Properties and Adhesion of P.V.D. Tungsten Films on Si and Silicon Compounds by Bulge and Blister Tests

1998 ◽  
Vol 518 ◽  
Author(s):  
Michel Dupeux ◽  
Alain Bosseboeuf ◽  
Denis Buttard
Keyword(s):  
Mechanical Properties ◽  
Silicon Oxide ◽  
Mechanical Test ◽  
Test Methods ◽  
Curvature Radius ◽  
Mechanical Equilibrium ◽  
Silicon Compounds ◽  
Young’S Moduli ◽  
Interfacial Fracture Energy ◽  
Deposition Conditions

AbstractP.V.D. tungsten films deposited on silicon wafers (covered or not with a P.E.C.V.D. silicon oxide, nitride or oxynitride sublayer) were submitted to bulge and blister tests. The mechanical equilibrium and geometry of the bulged tungsten membranes is compared to various models. From this analysis, values of the residual stresses and the Young's moduli in the films are derived, and found to be consistent with previous values deduced from curvature radius measurements or other mechanical test methods, as functions of the deposition conditions. Decohesion of the films from their substrates is easily observed on the W / SiO2 / Si membranes, and the film / sublayer interfacial fracture energy is estimated about 1 J/m2. This energy increases when the sublayer is changed from SiO2 to silicon oxi-nitride and to nitride. The W / Si membranes show a much stronger adhesion than the abovementioned ones and could not be debonded before bursting.

Mechanical Property Studies on Flax Fiber Reinforced Basalt Powder Filled Polyester Composite

2020 ◽  
Vol 13 ◽  
Author(s):  
V. Arumugaprabu ◽  
K.Arun Prasath ◽  
S. Mangaleswaran ◽  
M. Manikanda Raja ◽  
R. Jegan
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Natural Fiber ◽  
Tensile Load ◽  
Flax Fiber ◽  
Flexural Properties ◽  
Weight Percentage ◽  
Tensile Impact ◽  
Polyester Composite ◽  
Additional Support

: The objective of this research is to evaluate the tensile, impact and flexural properties of flax fiber and basalt powder filled polyester composite. Flax fiber is one of the predominant reinforcement natural fiber which possess good mechanical properties and addition of basalt powder as a filler provides additional support to the composite. The Composites are prepared using flax fiber arranged in 10 layers with varying weight percentage of the basalt powder as 5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%, 25 wt.% and 30 wt.% respectively. From the results it is inferred that the composite combination 10 Layers of flax / 5 wt.%, basalt Powder absorbs more tensile load of 145 MPa. Also, for the same combination maximum flexural strength is about 60 MPa. Interestingly in the case of impact strength more energy was absorbed by 10 layers of flax and 30 wt.% of basalt powder. In addition, the failure mechanism of the composites also discussed briefly using SEM studies.

scholarly journals Mechanical Properties of Graphene Oxide Coupled by Multi-Physical Field: Grain Boundaries and Functional Groups

Crystals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 62
Author(s):  
Xu Xu ◽  
Zeping Zhang ◽  
Wenjuan Yao
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Grain Boundaries ◽  
Functional Groups ◽  
Oxygen Content ◽  
Tensile Fracture ◽  
Hydroxyl Groups ◽  
Molecular Configuration ◽  
Spatial Design ◽  
Out Of Plane

Graphene and graphene oxide (GO) usually have grain boundaries (GBs) in the process of synthesis and preparation. Here, we “attach” GBs into GO, a new molecular configuration i.e., polycrystalline graphene oxide (PGO) is proposed. This paper aims to provide an insight into the stability and mechanical properties of PGO by using the molecular dynamics method. For this purpose, the “bottom-up” multi-structure-spatial design performance of PGO and the physical mechanism associated with the spatial structure in mixed dimensions (combination of sp2 and sp3) were studied. Also, the effect of defect coupling (GBs and functional groups) on the mechanical properties was revealed. Our results demonstrate that the existence of the GBs reduces the mechanical properties of PGO and show an “induction” role during the tensile fracture process. The presence of functional groups converts in-plane sp2 carbon atoms into out-of-plane sp3 hybrid carbons, causing uneven stress distribution. Moreover, the mechanical characteristics of PGO are very sensitive to the oxygen content of functional groups, which decrease with the increase of oxygen content. The weakening degree of epoxy groups is slightly greater than that of hydroxyl groups. Finally, we find that the mechanical properties of PGO will fall to the lowest values due to the defect coupling amplification mechanism when the functional groups are distributed at GBs.

scholarly journals Regulating Effect of Cement Accelerator on High Content Solid-Wastes Autoclaved Aerated Concrete (HCS-AAC) Slurry Performance and Subsequent Influence

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 799
Author(s):  
Dingkun Xie ◽  
Lixiong Cai ◽  
Jie Wang
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Solid Wastes ◽  
Hydration Products ◽  
Promoting Effect ◽  
Adverse Side Effects ◽  
Foaming Process ◽  
Carbide Slag ◽  
Negative Effect ◽  
Aerated Concrete

Adverse side-effects occurred in slurry foaming and thickening process when carbide slag was substituted for quicklime in HCS-AAC. Cement accelerators were introduced to modify the slurry foaming and coagulating process during pre-curing. Meanwhile, the affiliated effects on the physical-mechanical properties and hydration products were discussed to evaluate the applicability and influence of the cement accelerator. The hydration products were characterized by mineralogical (XRD) and thermal analysis (DSC-TG). The results indicated that substituting carbide slag for quicklime retarded slurry foaming and curing progress; meanwhile, the induced mechanical property declination had a negative effect on the generation of C–S–H (I) and tobermorite. Na2SO4 and Na2O·2.0SiO2 can effectively accelerate the slurry foaming rate, but the promoting effect on slurry thickening was inconspicuous. The compressive strength of HCS-AAC obviously declined with increasing cement coagulant content, which was mainly ascribed to the decrease in bulk density caused by the accelerating effect on the slurry foaming process. Dosing Na2SO4 under 0.4% has little effect on the generation of strength contributing to hydration products while the addition of Na2O·2.0SiO2 can accelerate the generation and crystallization of C–S–H, which contributed to the high activity gelatinous SiO2 generated from the reaction between Na2O·2.0SiO2 and Ca(OH)2.

Pinning-assisted out-of-plane anisotropy in reverse stack FeCo/FePt intermetallic bilayers for controlled switching in spintronics

2021 ◽  
pp. 160249
Author(s):  
Garima Vashisht ◽  
Utkarsh Shashank ◽  
Surbhi Gupta ◽  
Rohit Medwal ◽  
C.L. Dong ◽  
...  
Keyword(s):  
Controlled Switching ◽  
Plane Anisotropy ◽  
Out Of Plane

In-Plane Stiffness and Yield Strength of Periodic Metal Honeycombs

2004 ◽  
Vol 126 (2) ◽  
pp. 137-156 ◽  
Author(s):  
A.-J. Wang ◽  
D. L. McDowell
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Relative Density ◽  
Cell Types ◽  
Elastic Stiffness ◽  
Honeycomb Structures ◽  
Initial Yield ◽  
Cell Structures ◽  
Plane Anisotropy ◽  
Different Cell Types

In-plane mechanical properties of periodic honeycomb structures with seven different cell types are investigated in this paper. Emphasis is placed on honeycombs with relative density between 0.1 and 0.3, such that initial yield is associated with short column compression or bending, occurring prior to elastic buckling. Effective elastic stiffness and initial yield strength of these metal honeycombs under in-plane compression, shear, and diagonal compression (for cell structures that manifest in-plane anisotropy) are reported as functions of relative density. Comparison among different honeycomb structures demonstrates that the diamond cells, hexagonal periodic supercells composed of six equilateral triangles and the Kagome cells have superior in-plane mechanical properties among the set considered.

Effects of Nano-Al2O3 on the Mechanical Property and Microstructure of Nano-Micro Composite Self-Lubricating Ceramic Tool Material

2013 ◽  
Vol 770 ◽  
pp. 308-311 ◽  
Author(s):  
Ming Dong Yi ◽  
Chong Hai Xu ◽  
Zhao Qiang Chen ◽  
Guang Yong Wu
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Tool Material ◽  
Ceramic Tool ◽  
Ceramic Tool Material ◽  
Composite Self ◽  
Microstructure And Mechanical Property ◽  
Grain Refinement Strengthening

A new nanomicro composite self-lubricating ceramic tool material was prepared with vacuum hot pressing technique. The effect of nanoAl2O3 powders on the microstructure and mechanical properties of nanomicro composite self-lubricating ceramic tool material was investigated. With the increase of nanoAl2O3 content, the hardness and fracture toughness first up then down. When the nanoAl2O3 content is 4 vol.%, the flexural strength, hardness and fracture toughness reaches 562 MPa, 8.46 MPa·m1/2 and 18.95 GPa, respectively. The microstructure and mechanical property of nanomicro composite self-lubricating ceramic tool material can be improved by the grain refinement strengthening of nanoAl2O3.

Effect of Quaternary Ammonium-Modified Montmorillonites on Mechanical Properties of Polypropylene

1998 ◽  
Vol 520 ◽  
Author(s):  
Y. H. Zhang ◽  
K. C. Gong
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Tensile Strength ◽  
Impact Strength ◽  
Quaternary Ammonium ◽  
Small Addition ◽  
Pp Composites ◽  
Addition Amount

ABSTRACTHybrids of quaternary ammonium-modified montmorillonites and polypropylene were prepared by melting intercalation. Results of mechanical property measurements show that, tensile strength, modulus and impact strength of PP composites are greatly enhanced simultaneously by a small addition amount of modified montmorillonites.

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