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In the present work we report on the effect of pre-deformation followed by/together with artificial aging on the mechanical properties as strength, ductility and work hardening of an Al-Mg-Si alloy (AA6060).
The aging behaviour and mechanical properties have been characterized in terms of Vickers hardness and tensile testing.
It is found that small, even very small, pre-deformations strongly affect the aging behaviour and associated tensile properties.
The main hardening precipitates are expected to be β’’, which contribute significantly to the final mechanical properties due to their small size and homogeneous distribution.
However, this is counterbalanced by the strain hardening contribution from pre-deformation to the final mechanical properties.

The prepared nano high polymer resin and carbon cloth were made into nano-prepreg by using ultrasonic impregnation method, and a nano-prepreg composite material was prepared by using hot compacting and cut to test pieces to measure its mechanical properties and surface conductivity as well as the influence of temperature-humidity environment (85˚C/168hr and 85˚C/85%RH/168hr) on mechanical properties.
Current studies on carbon aerogels mostly focused on the thermal properties and adsorbability.
Therefore, this study aimed to examine the synergistic effect of making carbon aerogels of different proportions (0, 0.025, 0.1, 0.25 phr) and PEO (0.5 phr) modified phenolic resin and carbon cloth into nano-composite, especially the influence on mechanical properties after the surface conductivity and mechanical properties are affected by temperature-humidity environment.
When the phenolic resin is immersed in a supersaturated moisture environment, the adhesive force of resin would decrease, and shrinkage occurs in the vertical direction of pressure that results in microcracks, all the above factors would reduce the tensile strength of material rapidly.
PEO modifying agent forms netty crystals in phenolic resin, although it can improve the mechanical properties of phenolic resin, in such a long-term high temperature and supersaturated moisture environment, the hydrogen bond and oxygen are combined into long chain -OH- radical that reduces the mechanical properties greatly.

The refined α grains and Ca-containing Mg12RE with higher thermal stability are considered to be responsible for the improved mechanical properties at room and elevated temperatures for the EZ43-Ca alloys.
Consequently, leading challenges to widespread use of the Mg alloys have focused on the improvement of their mechanical properties at elevated temperatures [2-4].
Taking these previous results into account, it is reasonable to expect that Ca may play a beneficial role in improvement of mechanical properties at room and elevated temperatures in case of Mg-RE based alloys.
Lee et al. [8] reported that solute elements such as Zr, Ca and Si possess higher growth restriction factors on Mg due to their strong segregating power.
Summary The microstructures and mechanical properties at ambient and elevated temperatures up to 300 o C have been investigated for EZ43(Mg-4%RE-3%Zn)-(0~1.2)%Ca casting alloys.

The low carbon steels were smelted with special oxide introduction technique and the HAZ properties has been studied with thermal simulation.
The optical microscope, SEM and TEM were used to analyze the composition, size and distribution of the inclusions, and the mechanical properties after thermal simulation were also investigated.
These two factors are the main causes to improve the toughness of heat affected zone for steels produced by oxide metallurgy technique.
However, after welding (especially the large heat input welding), the weld heat affected zone (HAZ) has undergone high-temperature reheating process, and the parent material’s fine-grained microstructure has been broken as the austenite grain in this region grow up seriously.
The HAZ properties had been studied with thermal simulation.

Some key indexes that affect the properties of segment were tested, such as impermeability, volume stability, mechanical property, etc.
Furthermore, the mechanical properties of concrete cover and concrete structure layer met the project requirement perfectly, ensuring the higher durability and longer service-life of HCCS effectively.
Comparing to industry and civilian construction under the open air, the factors affecting structural durability are more complex in tunnel construction, which is often exposed to all kinds of environmental effects resulted from not only the internal air but also the external soil and groundwater [2].
Furthermore, this investigation tested some key indexes such as impermeability, volume stability and mechanical property, which usually affect the properties of concrete segment, appraising the service life and properties of HCCS based on the data analysis in a series of experimental studies.
Test and results of mechanical properties.

The most common causes of failure of the timber structural systems are inadequacy of configuration in relation to the actions, static and dynamic loading, besides slenderness, instability, defects of the wood, severe biotic damages, and accidental factors [1].
A complete set of information regarding wooden member properties and state allows selection of the most suitable conservation procedure.
Results and discussion Mechanical properties of timber are highly related to its chemical composition.
The hydrogen bonds affect in consequence several physical/mechanical properties of wood on the macro scale.
The contribution of hemicelluloses on the overall mechanical properties of wood is rather not significant due to its limited content, but on the other hand the hemicelluloses might be affected by deformations of cellulose chains and lignin zones as resulted to mechanical stresses.

Simultaneously, it improves the combustion properties of biomass fuels, and increases the efficiency in the use of biomass resources.
In this article, by researching the characteristics of the compressed rice straw fiber, biomass formation mechanism and its influence on shaping factors, the better conditions in processing of rice straw compression molding are concluded.
While it improves the combustion properties of biomass fuels, and increases the efficiency in the use of biomass resources.
The main factors of biomass compression and molding are: material type, moisture content, particle size, forming pressure and the shape of the die size and the temperature.
The mechanical structure diagram is shown in Figure 9.

The change of steel mechanical properties is because of steel corrosion seriously.
Introduction Steel corrosion seriously affects its mechanical performance.
It is important to study the mechanical properties time-varying law of the corroded steel for the nondestructive testing and evaluation of the actual structures.
To sum up, few research has been studied the corroded steel mechanical properties changes.
[7] Shi Bin, in: Degraded relations study on corrosion of steel surface characteristics and mechanical properties.

Based on this, the sensitivity analysis of the factors affecting the pressure carrying capacity of the pipeline, such as the internal pressure, the confinement state and the material performance, was carried out.
In this paper, the pressure carrying capacity of X80 pipe with plain dents and its influence factors such as internal pressure and material properties will be studied through FEA method, which can provide the basis for safety assessment of the dent pipelines.
The constitutive curve of material properties is shown in Fig. 2.
Fig. 2 Constitutive curve of material properties Simulation Result Effect of the Internal Pressure.
Conclusion The sensitivity analysis of the factors affecting the pressure carrying capacity of the dent pipe has been carried out, and the following conclusions can be obtained

Investigation on Delamination Factor in Drilling Medium Density Fiberboards with Variable Feed Pressure using Multi-Spindle Drill Kun Wang1, a, Cheng Wang1, b and Meng Gao1, c 1College of Mechanical Engineering, Tongji University, 200092, Shanghai, China akunwang@tongji.edu.cn, btjchengtj@126.com, cmenggaotj@126.com Keywords: drilling, medium density fiberboard (MDF), delamination factor, response surface methodology, analysis of variance (ANOVA) Abstract．Drilling quality in manufacturing medium density fiberboards (MDF) is greatly affected by delamination.
Literature survey reveals that no systematic study has been reported to analyze the main and interaction effects of drilling process by a multi-spindle drill on delamination factors.
The important properties of the tested medium density fiberboard (MDF) are given in Table 2 [5].
Experimental factors and levels Factor Notation Unit Factor levels Low High Feed pressure P [MPa] 4.5 6.5 Drill diameter D [mm] 6 10 Drill hardness H [HRC] 60 90 Table 2 Mechanical and physical properties of MDF tested Tensile strength [N/mm2] Modulus of rupture [N/mm2] Elasticity modulus [N/mm2] Humidity % Density [Kg/m3] 0.8 28 2800 5-8 600-900 The delamination factor (Fd) is determined by the ratio of the maximum diameter (Dmax) of the delamination zone to the diameter of the hole [7].
The P value of last column indicates which item significantly affects the model.