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Fine microstructure and excellent weld shape can be obtained by choosing reasonable technology parameters and the mechanical properties of welding joint can also be promoted.
The increasing of Al in magnesium alloy is beneficial to thinning the grain and to improve the mechanical properties.
The Mechanical Properties of Welded Joints of Magnesium Alloy Wang et al [17] used CO2 laser welding system to weld AZ31 magnesium alloy and studied the microstructure and property of the welded joints.
This shows that using laser welding technology to weld AZ31 magnesium alloy can improve the mechanical properties of welded joints.
The pores may be reduced by adjusting the parameters, preheat and eliminating the factors of gas, but they can't be entirety avoided[21].

To accurately calculate the prestress of externally prestressed composite girder bridges, the six critical factors (the prestressing tendon withdrawal and anchor deformation, friction between prestressing tendon and deviator, prestressing tendon relaxation, concrete creep, concrete shrinkage and temperature changes) that cause the prestress loss of such type of the bridges are summarized and the corresponding simplified calculation methods are respectively derived on the basis of the existing researches.
The prestressing tendon’s ability has an important influence on the mechanical behavior of prestressed composite girder bridges, which is the key design parameters.
On the basis of existing research, this paper summarizes the key factors that lead to loss of prestress and derives the corresponding simplified calculation method for design reference.
During the design of prestressed concrete , due to factors affecting the construction , material properties , and environmental conditions, prestress in tendon will gradually decrease, the phenomenon is called prestress loss.
The temperature changes loss As the external tendon is outside the beam cross-section, due to the temperature difference between day and night, seasonal temperature and other environmental factors, the temperature in the use phase is higher than that of tension construction.

Factors of Adhesion between Asphalt and Mineral Aggregates Chuanfeng Zheng 1,a, Shi Zheng 2,b 1College of Construction Engineering, Jilin University, Changchun, Jilin Prov, P.R.
The interaction may be in the form of chemical bonding, mechanical connection, or both.
(1) Effects of the studied factors Preparation temperature of the mixture.
The significant differences among the properties and structures of the main components of the minerals influence the contact angle between the asphalt and mineral aggregate.
Compatibility of multi-factors and the calculation of the adhesion work The surface tension cannot be combined with the contact angle in a single analysis.

Key words: Single-slag Process, high-aluminum cold heading steel, composition control, property Abstract: Based on the actual process for smelting cold heading steel, this article adopts the single-slag process to smelt the low-carbon, low-silicon and high-alumina cold heading steel SWRCH6A, so as to study the effect of technological factors of the smelting process on the change of molten steel component in various working procedures and steel properties.
All the mechanical properties of cold heading steel exceed the ML08Al standard.
For mechanical properties of each item, see Table 3.
Table 3 Mechanical Properties of High-Aluminum cold heading Steel Smelting by Single-slag Process Batch No.
All the mechanical properties of the cold heading steel exceed the ML08Al standard.

Carrier mobility of the graphene thin film is one of the most crucial factors to achieve superior device performance.
Factors that influence the carrier mobility include film crystallinity, layer number, presence of contaminations, and effect of the substrate.
However, factors such as surface phonons [10], roughness [11], and trapped charges [12] restrict the carrier mobility.
The graphene thin-film is expected to possess superior electrical properties.
Young, Mechanical properties of graphene and graphene-based nanocomposites, Progress in Materials Science. 90 (2017) 75-127

This has led to a wide range of applications as structural materials especiallyin aircraft structures[2,3,4].Thermal residual stress, produced by the curing and cooling process, is one of the important factors which can affect the mechanical performances of composites.Many researchers have fully investigated thermal resudual stress in composites through numerical or experimental methods [5,6,7].
Matrix-fiber debonding affects the performance of fiber-reinforced composites.It was found that the mechanical properties of composites under transverse compression were mainly controlled by interface strength and the failure of composites was due to the interface debonding[9,10,11,12,13].
It is clearly shown that S23 are higher than S13 and S33 in the two models,so S23 is the dominant factor resulting in debonding.
Conclusion Since thermal residual stress is one of the important factors which can affect the mechanical performances of composites, we presented a three-dimensional finite element model to investigate the effects of nanoparticles on the interface strength of unidirectional fiber reinforced composites.The comparison between the results of two models show that the thermal residual stress in the model with nanoparticles is significantly reduced, while the shear stress in the model without nanoparticles is the dominant factor resulting in interface debonding.
Mittal, Effect of architecture on mechanical properties of carbon/carbon composites, Composite Structures. 83 (2008)131-142

Federici et al.[3]demonstrated that the thermal properties of reactor materials play a vital role in the overall thermal stability of micro-reactors.
To extend the operation range and to study the interplay of methane/moist air reactions in microchannel-reactors, this paper simulated the methane/moist air catalytic combustion with fluent software in mirochannels with different wall shapes and analyzed the impact of different surface shape factors on the methane/moist air catalytic combustion .
Numerical Model and Chemical Mechanical Physical Model.
This is because the groove in the microchannel increased wall roughness, thereby affecting the residence time of the combustion gas.
A single groove on the overall average mass fraction of each component is not affected.

It is used in a variety of micro structural conditions, depending on the properties desired.
Previous studies have suggested that the fatigue behavior and mechanical properties of α+β titanium alloys are greatly influenced by their microstructures.
Many of these researches have an overall view on microstructure affect on fatigue crack growth rate with no attention local view of microstructure affect on crack growth path.
The shape of this microstructure is shown in Fig.1; the composition of the material is given in table 1 and table 2 specifies mechanical properties of Ti-6Al-4V forged plates.
Room temperature material properties of Ti-6Al-4V forged plate Fractography.

In transportation industry such as aerospace environment, the material has to present damage tolerance corresponding at least to the standard 2024-T3 material properties.
It can be even so noticed that Krs in 6056-T78 is higher than in the both other materials; it is in accordance with the tensile properties.
The curves are even more comparable between the factors studied with CCT specimens.
Both heat treatments conditions as-welded and post-welded, applied to material 6056-T78, showed the comparable crack propagation, even if post-welded treatment is recommended in term of mechanical properties.
[7] Lafly A-L, Alléhaux D, Marie F, Dalle Donne C, Döker H: " Impact of Friction Stir Welding Techniaues on microstructure changes and mechanical properties", 58th Annual Assembly and International Conference of International Institute of Welding (IIW), Prague, 10-15 July 2005

At present, Mg-Gd-Y-Zn-Zr alloys with significant mechanical properties due to the existence of long period ordered phase (LPSO phase) in their microstructure have become the focus of rare earth magnesium alloys because of their remarkable mechanical properties [5-8].
It can be seen from the characteristics of the flow stress curve shown in Fig. 2 that the factors affecting the rheological behavior of the compression-torsion deformation are temperature, strain rate and strain.
Zhang, The intrinsic effect of long period stacking ordered phases on mechanical properties in Mg-RE based alloys, J.
Zhang, The intrinsic effect of long period stacking ordered phases on mechanical properties in Mg-RE based alloys, J.
Yuan, Microstructure development and tensile mechanical properties of Mg-Zn-RE-Zr magnesium alloy, Mater.