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Precipitation-hardenable 6xxx series aluminum alloys are incorporated in many structural components with due consideration of their good combination of properties including a relatively high strength, outstanding extrudability and excellent corrosion resistance.
In this respect, friction stir welding (FSW) presents a tremendous potential for assembly of aluminum structures for the transportation industry due to the low heat involved that can mitigate crack formation and, thus, translate into improved mechanical performance of the assembly.
Figure 5: Microstructure for double pass FSLW – Tool geometry C, 1750 rpm, 8 mm/s: (a) Weld nugget, (b) Thermo-mechanically affected zone and (c) Heat-affected zone.
Reynolds, Factors affecting the properties of friction stir welded aluminum lap joints, Welding Journal 80 (12) (2001) 281–7
Jahazi, Process optimisation and mechanical properties of friction stir lap welds of 7075-T6 stringers on 2024-T3 skin, Materials and Design 31 (2010) 3324–3330.

The simulation results show that shaft rotating speed, ball materials, axial preload and the initial contact angles to some extent impact the bearing stiffness while have little affects on system nature frequency and the rotor unbalance response which greatly affected by the system base stiffness.
After comparing experimentally the stiffness and damping properties of DDHPB with those of conventional rolling-element bearing [2], Prashad reports them better than those of the conventional bearings.
Establishment of Geometric and Mechanical Model of DDBB Mechanical Model.
The structure and detailed ball mechanical model of DDBB are depicted in Fig.1 and Fig. 2 respectively. 2gjM 2ojQ 2cjF ' 2ojα ' 2ijα 2 2 2 ij gj bM Dλ 2ijQ 1 1 1 oj gj bM Dλ 1gjM 1ojQ 1cjF ' 1ojα ' 1ijα 1 1 1 ij gj bM Dλ 1ijQ Fr aF 2 2 2 oj gj bM Dλ Fig. 1 Structure of DDBB Fig. 2 Ball mechanical model Structure of DDBB Fcjε, Mgjε, Qijε and Qojε respectively denote the jth ball centrifugal force, gyro moment of the εth series, ball-race contact forces at corresponding inner and outer race. λij1, λoj1, λij2 and λoj2 are introduced correction factors.
All of those correction factors equal 1 when DDBB rotates at low speed.

In this work, a mathematical model is developed to predict three-dimensional force components and axial torque of the rotating tool based on contact mechanic principle in relation to Al6061 temperature-dependent material properties.
The model shows the ability to be possibly adapted for different metallic material and physical properties.
To determine the effect of the welding parameters toward the success of defect free welding during the FSW process, a lot of interrelated parameters need to be accessed in order to have the most optimum process hence the controlling boundaries are to be recognized in form of measurable unit that affecting each other.
In addition, Fig. 2b shows the asymmetry properties of the process which favour to the direction of tool rotation.
Controlling boundaries are to be recognized in form of measurable unit that affecting FSW parameter.

The factors that contributed to the evolution of SiC particles distribution feather during plastic deformation were analyzed.
Introduction The attractive physical and mechanical properties of metal matrix composites(MMCs), such as high specific modulus, specific strength, wear resistance and low thermal expansion coefficient etc., have been documented extensively [1-5].
However, the subsequent cold and hot deformation are of great effects on the mechanical properties of the products[7].
As to the inhomogeneous distribution of SiCp of the as-deposited SiCp/7075Al in the deposition direction, there may be two main factors that affect the uniform distribution of SiCp.
(2) There may be two main factors, which result in the clustering distribution of SiCp during deformation.

Since no intermediate transmission links, mechanical friction is greatly reduced, so that the moving noise is decreased and the energy loss caused by friction and elastic deformation is greatly reduced too. 4 Key technology problems and solution countermeasures It can be said that the development and application of linear motors has promoted the development of modern machine tool technology, and may cause a revolutionary changes in the structure and properties of the machine tool.
(1) Efficiency and power factor Compares with the same capacity rotating motor, the efficiency and power factor is lower, especially at low speed.
Otherwise, if the heat dissipation is not good, it will restrict the intensity of electrical parameters (such as current), thereby constraining the size of the thrust and affecting the motor performance
(4) Servo control Although the linear motor feed system eliminates the elastic deformation of the intermediate transmission mechanism, the gap, friction and other factors which affect the system accuracy, all kinds of interferences (such as workpiece weight, changing of cutting force) are directly passed on to the linear motor without any intermediate links’ attenuation and increase the difficulty of servo control.
China Mechanical Engineering. 1997,8(4):85~88 (in Chinese)

Cellulose nano fibers (CNF) is a new type of filler which shows high efficiency in improving the physical and mechanical properties of starch-based biocomposite.
Other advantages are good mechanical properties, low density, low cost and abundant in earth.
This is indicated by the hydroxyl bond formation between cellulose and starch resulting in improvement of mechanical properties [11].
This factor affected in decreasing mechanical properties.
Zaritzky, Mechanical and thermal properties of yam starch films.

Transfer characteristics of austenite grain size, microstructures and key properties of high carbon rail during the process are also revealed.
The mechanical properties of flaky pearlite are closely related to the structure of pearlite [2-4].
The main factor affecting yield strength and fracture strength toughness of flaky pearlite is the spacing of flakes, and the relationship between them can be expressed by Hall-Petch formula.
The main factors affecting the plasticity of flake pearlite are the original austenite grain size and the lamellar spacing of pearlite.
Table 4 Tensile and impact properties corresponding to different heating processes No.

This study focuses on the effect of deposition time and heat treatment on Ni3Al coatings with respect to mechanical and microstructural properties of the material.
These complex alloy coatings validate significant structural properties such as low density, increase in yield strength with temperature, high strength in relation to the specific mass, oxidation resistance and excellent creep properties [8-12].
Both coated and heat treated samples were characterized for their structure, morphology and mechanical properties.
Suuthoff, Mechanical Properties of Intermetallics at High Temperatures, Vortrag ASM Materials Week, Indianapolis, (1989)
Natesan, Critical Factors Affecting the High-Temperature Corrosion performance of iron aluminides, Mater.

A change in the production route for manufacturing Ti6Al4V products, from the more traditional methods to an additive manufacturing route, requires an investigation of microstructure and mechanical properties because these are strongly influenced by the production route.
Structurally, good mechanical properties which are comparable to the bulk material were obtained.
One of the crucial factors was the β-transus temperature which defined the single β phase field and the α+β field.
Figure 2: SEM images of the top surface (perpendicular with building direction) Mechanical Properties As shown in table 1, the maximum load of the laser sintered parts is 46.29KN and the Young‘s Modulus is 112GPa for both specimen 1 and 2.
[5] Vrancken, B., Thijs, Lore,Kruth, Jean-Pierre,Van Humbeeck, Jan, Heat treatment of Ti6Al4V produced by Selective Laser Melting: Microstructure and Mechanical properties, in Journal of Alloys and Compounds2012.

This article is focused on changes in the properties of colored concrete due to frost.
Failure of the internal structure of concrete by frost, manifested by the formation of micro-cracks, is mainly caused by two factors.
Due to the fact that concrete is a heterogeneous material, its properties are affected by many factors.
Bulk density, water absorption and mechanical properties are summarized in table 1.
Results of measurement mechanical properties after freeze-thaw cycles were summarized in Table 2.