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The microstructure evolution during the extrusion process of AA6XXX aluminum alloys is getting a significant interest from extruders and researchers because of the effect of the grain structure on the extruded component properties.
Because there are so many affecting elements, it is extremely challenging to forecast the microstructure evolution and, as a result, research activities are still required to understand and control the aluminum alloy recrystallization behaviour.
The microstructure of these profiles, defined as the arrangement of crystals, grains, and phases at the microscopic level, plays a lead role in determining their mechanical properties, formability, corrosion resistance, and overall quality [5-7].
Material Properties AA6063 Density [Kg/m3] 2690 Specific heat [J/kg K] 900 Thermal conductivity [W/m K] 200 Thermal expansivity [m/K] 2.34*10-5 Young’s modulus [GPa] 68.9 Poisson’s ratio 0.33 Fig. 2.
Given the substantial influence of numerous process and metallurgical factors on the final grain size, as well as the complexity of the extruded geometries and the limitations associated with the chosen measurement methodology [10] for experimental grain dimension analysis, the ± 25% error range, which was similarly adopted by Donati L. et al. in [10], is regarded as indicative of good prediction accuracy.

A reduction in the tensile properties and fatigue life of aluminium alloy castings has been observed on account of material porosity[3, 4].Casting defects lead to not only reduced values of mechanical properties but also high scatter of these properties [2].
Aging temperature has been found to be an important parameter with respect to the mechanical properties obtained after heat treatment.
Table 1: Mechanical properties for two-step aged Hipped and non-Hipped samples of 354 S.No.
Table 2: Mechanical properties for modified aging treatment of Hipped and non-Hipped samples of 354 S.No.
It appears that in this case the scatter has also been influenced by other factors.

Consequently, the efficiency of FEA during the ship assembly is highly affected.
The advantage of the quad-morphing algorithm is the property of robustness.
It will ensure the property of boundary sensitivity.
Furthermore, mesh generation is a significant link affecting the accuracy and efficiency of FEM.
It combines the property of boundary sensitivity and robustness.

The use of the homologous temperature T/Tm makes it possible to compare under corresponding conditions a number of the physical properties of crystalline materials determined by, for example, the self-diffusion phenomenon, but not the mechanical properties of crystals with different types of interatomic bonding and different crystalline structures.
Ivashshenko, et al., Structure, Texture, and Mechanical Properties of Deformed Molybdenum Alloys [in Russian], Naukova Dumka, Kiev (1983)
Goncharuk, et al., "Effect of temperature on the failure mechanisms and mechanical properties of semiconductor compounds of the type AII B VI ," Fiz.
Gridneva, "Mechanical properties of covalent crystals," Izv.
The structure and properties of sintered materials.

As the machine works at high speed, the real time changes of cutting force and other factors such as the external environment make the machine vibrate, which severely reduces the machining accuracy and surface quality of workpieces; while vibration also reduces the processing efficiency and accelerates the wear of tools, further affects the stability of the whole cutting movement[1-2].
Therefore, a key factor to improve the machining center performance and processing accuracy is to grasp the dynamic characteristics of the machining center[3-5]。
The vibration characteristics of machine can be expressed as a superposition of each order natural vibration modes, which lower-order modes have a greater impact on the dynamic properties of the entire organization.
Fig.3 The X-Direction Amplitude Frequency Response Curve Fig.4The Y-Direction Amplitude Frequency Response Curve Fig.5The Z-Direction Amplitude Frequency Response Curve Summary (1) By modal analysis, acquire its first six natural frequencies and mode shapes variations to determine the key of affecting the whole dynamic performance and the weak links of structures, and propose ways to improve.
Jixie Gongcheng Xuebao(Chinese Journal of Mechanical Engineering), 2010, 46(21): 54-60

They also displayed better mechanical, barrier, morphological and structural properties when the researchers analysed the impact of the electron beam irradiation on the nanomaterials.
For instance, a reinforcement of the pristine PLA material with the nanoparticles could significantly improve the mechanical and barrier properties of the material [7].
It was also noted that the PLA properties were affected by the clay addition and an ebeam irradiation treatment.
Domenek, Influence of chemical surface modification of cellulose nanowhiskers on thermal, mechanical, and barrier properties of poly (lactide) based bionanocomposites.
Rhim, Effect of clay contents on mechanical and water vapor barrier properties of agar-based nanocomposite films.

The coarse aggregate was made of abandoned concrete members by manual breaking to pieces and machine cyclic crushing, and sieved as continuous grading with 5mm~26.5mm grains, the basic properties are listed in Table 1.
Table 1 Basic properties of recycled coarse aggregate Grain size (mm) Compactness bulk density (kg/m3) Apparent density (kg/m3) 1h water absorption (%) Crush index (%) (ratio: 4/3/3) 5-10 10-20 20-26.5 1460 2651 4.55 24.8 The longitudinal tensile steel bars were HRB335 with test yield and ultimate strengths as list in Table 2.
Table 2 Mechanical properties of steel bars Steel bar 12 18 22 25 Yield strength fy（MPa） 420 390 390 375 Ultimate strength fsu（MPa） 625 580 595 575 Table 3 Mix proportion of recycled concrete Design strength Raw material dosage (kg/m3) W/C Sand ratio Slump (mm) cement Machine-made sand Recycled coarse aggregate Water Adsorption water Water reducer C30 300.0 864.2 1081.1 165 51. 9 1.49 0.55 0.44 65 C40 366.7 820.7 1086.2 165 51.5 1.83 0.45 0.42 102 C50 458.3 657.4 1148.8 165 52.5 2.28 0.36 0.36 105 Seven beams were designed different recycled concrete strength and reinforcement ratio, the length was 3.5m, the span was 3.2m.
Influencing Factors on Flexural Resistance of Beam.
Obviously, the reinforcement ratio was the main factor influencing the flexural resistance of reinforced recycled-concrete beams.

Recent researches [5] have pointed out that the fracture toughness is also depended on microstructure factors.
Mechanical property.
The mechanical properties of the drill pipe steel were summarized in Table 3, Figure 2 and 3 respectively.
To sum up, the result indicated that the new steel could reach 150ksi grade at 625℃ and gained the excellent matching properties of strength and toughness.
However, the coarse M3C carbide is an important factor affecting toughness.

From this study, it was found that different types of lubricant affect the wear progression and friction coefficient during a sliding movement.
Lubrication can be used in an engineering system without replenishment and is an important factor in increasing the lifetime of mechanical components.
Material and Method The pin-on-disk machine is a laboratory apparatus used for measuring friction and wear properties (ASTM G99).
This is one of the reasons why increasing normal pressure is a major factor contributing to the wear rate.
Coefficients of friction are further factors that contribute to the wear progression of the pin.

Introduction As reported already, graphene exhibits a huge number of remarkable electronic and mechanical properties, such as unconventional integer quantum Hall effect[2]-[3], ultrahigh electron mobility[4]-[5], which is possible to arrive at 2 million cm2/Vs even at room temperature, structure of hexagonal symmetry lead to electron-hole symmetry[6]-[7] and ultrahigh thermal conductivity at about 3000~5000W/mK which is as well as CNT[8].
Some exotic properties, like absorbing hydrogen at low temperature[9], di-pole semiconductor feature displayed in experiment[10], Ballistic transport in room temperature[11], et al.
There are two main factors which influent the quality of graphene deposited on thin nickel layers, one is the sort of metal which graphene grown on, and the second is the rate of cooling after heating CH4 where carbon atoms original from.
The quality of SiC played a magnitude role in affect the surface morphology of graphene[17,18,19].
Less foreign matter adhered on the surface may be the most significant advantage in pyrolysising to grow graphene, as shown in Fig.1 (c) Applications The potential application of graphene must be no doubt to be the substitute of SiO2 used in transistor as channel, for the superior electronic and thermal properties.