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The barriers include the dispersion of nanoparticle, the effect of nanoparticle concentration and interface on the overall properties of materials.
The results also showed that crystallization was enhanced because of existence of nanoparticles, which should have increased the mechanical properties of the composite and decreased its resistivity because of the interfacial action between CB particles and polymer matrix.
From the view of industrial application of the materials, it is a crucial to control the properties of parts through adjusting processing parameters.
But it is not clear whether the change-like affects the conductivity of composites and how it does.
The objective of this study was to systematically investigate the relation between microstructure and conductivity of the parts to improve the application of injection molding process, and find out the factors to increase the conductivity of the composites through controlling the processing techniques.

Some of them focused on material properties [3, 4].
Therefore, the dies will undergo a complex thermo-mechanical load during the forming process.
The high temperature or the uneven temperature distribution on dies will result in decrease of dies mechanical properties and reduce the die lifetime greatly, and even cause the part quenched incompletely.
One is to control the maximum temperature to maintain a relatively low level, in order to ensure the quenching effect and die’s mechanical properties.
In hot stamping process, the change of the die temperature is mainly affected by two factors: One is the heat flux from high temperature blank to die; another is that from dies to cooling systems.

Taheri3, c 1Department of Mechanical Engineering, Ayatollah Amoli Branch, Islamic Azad University, Amol, Iran 2Faculty of Mechanical Engineering, Sama Technical and Vocational Training College, , Islamic Azad University, Ayatollah Amoli Branch, Amol, Iran 3Department of Industrial Engineering, Mazandaran University of Science and Technology, babol, Iran am_hoseinzadeh59@yahoo.com, bSali86_mk@yahoo.com, calitasana@yahoo.com Keywords: Sheet Hydroforming, Optimization, Taguchi Method.
Fig. 3 Photograph of the manufactured die set mounted on the test machine The applied material is St14 steel sheet with 1mm thickness and its properties that were obtained by tensile test are shown in Table 1.
Table 1: Mechanical properties of St14 Density,ρ [Kg/m3] Poisson’s ratio Yield stress, σ [Mpa] Strength coefficie, K [Mpa] Strain hardening exponent, n Young’s modulu, E [Gpa] 7800 0.3 201 610 0.24 210 To applying Taguchi Method, three pressure paths were used.
Table 5: Optimum condition Factor Level description Level PU thickness 10 1 Pressure path P3 3 PU hole diameter 55 2 PU hardness 80 2 Conclusions The process parameters that affect the sheet hydroforming with the new die-set process have been studied using Taguchi technique.
The variables affecting the forming pressure according to their relative significance are the forming pressure path, the polyurethane hardness, the polyurethane hole diameter and the polyurethane thickness, respectively.

Depending on the number of elements, their properties, and regularities of their interaction in the grinding systems, transformation of the shape occurs under dynamic or static stress of the system.
The speed of elastic tightness on the system depends on the value 0t , the properties of the work piece, and the tool.
It is due to the fact that performance factors, affecting accuracy of the grinding systems, are elastic and thermoelastic deformations in the system.
Journal of Mechanical Engineering.
Assoc Mechanical Engineers Technicians Slovenia, Vol. 51, No 2, 2005), p. 95-102 [2] V.

The BI component, however, contributed an additional amount of resistance that depended in part on the angle value imposed between wire and bracket but also on the elastic properties of the wires (elastic modulus).
In this case, the elastic property (elastic modulus) became an important factor for the level of resistance of sliding.
Summary Shape memory alloys such as NiTi alloys display great interest in dentistry because of their peculiar elastic properties.
Our results showed that the archwire mechanical properties (especially elastic properties) appeared to be a factor that can significantly influence the friction, which depends both on surface and mechanical properties.
Then, coefficient of friction and orthodontic wire stiffness are the two critical factors influenced the friction generated when an orthodontic wire slides through non-aligned brackets.

Attributed to different elastic properties of the grain orientations, different slopes in the elastic region are observed.
Nevertheless, it is generally accepted that at low strains, the twinning behaviour can be explained by the shear stress criterion (Schmid factor).
The formation of twinning also requires multiple slip preceding the formation of twins [6] and mechanical twins were observed in γ-<111>//L at both low and high strains [5,6,8].
On the other hand, the same authors did not find twins in the γ-<200>//L orientation at low or high degree of plastic deformation, which was explained by its low Schmid factor for twinning but high Schmid factor for slip.
Mechanical twins have been proposed to affect the plastic behaviour through “grain refinement effect” or dispersion strengthening.

Current analytical techniques for simulating the generation of residual stresses within welded structures make approximations and simplifications relating to the mechanical properties of the weld metal.
Anisotropy becomes an important factor when the thickness of the plates increases.
Designers usually make approximations about weld metal properties such as the elastic modulus.
We have tried to investigate the anisotropic properties of the weld metal by subjecting the weld specimen to in-situ tensile loading in the neutron beam.
A 50kN Instron hydraulic stress rig available on ENGIN-X for in situ mechanical loading was used for this experiment.

Chemical compositions of Grade 91 steel C Mn P S Si Cu Ni Cr Mo Al Fe V N 0.116 0.35 0.01 0.001 0.224 0.11 0.15 8.87 0.92 0.21 Bal 0.18 0.05 Grade 91 steel has excellent thermal properties with low thermal expansion coefficient and high thermal conductivity while it has high design stress intensity as shown in Fig. 1[7].
However, concerns of a cracking in a heat-affected zone and a subsequent failure, commonly known as a Type IV cracking, may exist at the welded joints for long term services. 0 5 10 15 20 Grade 91 Alloy 800H 316SS 304SS 2.25Cr-1Mo 12Cr Thermal exp. coeff.(1e-6) Thermal conductivity(Btu/hr ft F) 0 100 200 300 400 500 Grade 91 Alloy 800H 316SS 304SS 2.25Cr1Mo 12Cr Su Sy Sm Stress (MPa) 0 100 200 300 400 500 Grade 91 Alloy 800H 316SS 304SS 2.25Cr1Mo 12Cr Su Sy Sm Stress (MPa) Fig. 1 Thermal and mechanical properties of Grade 91 steel Finite Element Modeling.
Load (KN) time (min) Pre-cracking C-F loading (I) C-F loading (II) Beach-marking Hold time (1hr) p1 p2 P P Fig. 3 Mechanical loading conditions and specimens under mechanical loading A 3D quarter symmetric finite element model was used and the stress contours for the uncracked body and cracked body under mechanical loading of 10 tons and thermal loading are shown in Fig. 4.
As for the FCG for the Grade 91 steel base metal of the CT (1 inch thickness) specimen, the mathematical model for base metal of Eq. 1 at 550°C [3] was used. 1.83 7 d 9.3 10 d eff a K � −   = × ∆  (1) where effK∆ is an effective stress intensity factor range.
Mechanical Sci. and Technology, Vol. 20(12) (2006), p.2076

Almost 50 % of the inner surface is affected.
Comparison of the results obtained from different layers of concrete is another from the factors which is in a term of assessment highly-valued.
The physico-mechanical properties of concrete due to the reactions under way during the second stage of carbonatation do not decrease yet.
Decomposition of the cement matrix has been already showed by a drop of strength properties (especially cohesion) in surface layers of concrete.
One of the factors which take a part in massive failure development in this case is quite a high porosity of concrete (proved by high values of surface saturation).

The development of biomaterials may potentially mimic extracellular matrix (ECM) structure, chemical composition, and mechanical properties, which are involved in survival, spread, and proliferation of the cells.
However, the weak mechanical and swelling properties of the pure fibroin also limit its application in biomaterials.
Plasma treatment have been regarded as a green and effective one for modifying the surface properties or introducing desired chemical groups at the surface of a material without affecting its bulk properties [12].
PEOT/PBT is selected as the substrate material because it is an elastomeric one which has the good properties on swelling, degradability and mechanical strength.
As the outermost surface of biomaterials directly interfaces with the tissue or cells, the surface modification to PEOT/PBT will change its surface properties, thereafter affecting the biocompatibility between the cells (or tissue) and the material, which could be evaluated by some tests including HSG cells morphology, attachment, proliferation and viability in vitro. 2.