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In this study, it was demonstrated how second phases with small amount, which are hardly detected by XRD analysis, affect grain boundary dissolution and related mechanical properties of HA.
Following certain period of exposure to the distilled water, the surface dissolution initiated at grain boundaries and particle loosening, subsequently resulting in decrease in mechanical properties of HA.
However, the mechanical properties like fracture toughness of HA ceramics can be drastically decreased by body fluid causing particle loosening and microstructural degradation of materials when implanted in body [3,6-8].
It has been known that there are factors controlling the biological behavior of calcium phosphate materials such as the physical characteristics, chemical composition and crystal structures [9,10].
Conclusions This study has focused on the dissolution behavior of hydroxyapatite affected by grain boundary structure and crystal orientation.

The recent development in thermo-mechanical modelling of FSW process is described with particular reference to two major factors that influence the performance of FSW joints: material flow and temperature distribution.
Consequently, the properties of FSW have been the subject of a considerable amount of experimental and numerical studies [4-10].
Temperature dependent properties of the weld-material have been used for the numerical modelling.
The results also indicated that weld speed could be the main input parameter that had the highest statistical influence on mechanical properties.
In this paper, the recent development in thermo-mechanical modelling of FSW process is described with particular reference to two major factors that influence the performance of FSW joints: material flow and temperature distribution.

The uniform zonal disintegration of surrounding rock is the peculiar phenomena of deep and high stress field, researching the inner mechanism and affecting factors has important meaning for guaranteeing the safety of deep engineering.
On the one hand, the unloading of surrounding rock make the stress field Change, On the other hand, the change of pore water pressure also change the effective stress of surrounding rock, which affecting the surrounding rock deform and crack evolution.
a) Destroy pattern of test[12] b) The shear plastic strain c) The plastic zone Fig2.The contrast between test and simulation(Step=20000,P=60MPa） Pore Water Pressure Affecting the Surrounding Rock Destroy Pattern.
a) pw=1MPa b) pw=4MPa c) pw=7MPa Fig.3 The rock destroy pattern by different pore water pressure(p=30MPa,step=2000) Other Factors Affecting Crack Pattern Simulation Calculation Scope.
Fig.5 is how the calculation scope affects the simulation results.

Thermal degradation properties were studied by thermogravimetry (TG).
In starch-based composite systems, one of important factors affecting mechanical properties is the interfacial affinity with the matrix polymer.
The mechanical properties including tensile strength and flexural strength were measured using a CMT-4104 comprehensive test instrument.
But the broad band in the range of 3760–3010 cm-1 does not visibly changed, so it means that only a small part starch reacted with maleic anhydride during the processing. 3.2 Mechanical properties The mechanical properties of pure PLA and the composites with different grafted starch content are shown in Table 1.
The properties of the composites are affected obviously by the grafted starch content.

The thermal stability of fine recrystallized grains in the nugget zone depends on process parameters and post-welding heat treatment and it has unusual consequences on mechanical properties.
The occurrence of this phenomenon may be a problem if it leads to a decay of mechanical properties of the weld.
The effects on tensile properties are considered too.
The factors that can affect the onset of AGG are as follows: anisotropy in grain boundary energy and mobility, reduction in pinning forces due to coarsening and/or dissolution of particles, and thermodynamic driving forces due to grain size distribution.
The AGG phenomenon seems to be a valuable mechanism for improving mechanical properties of these FSW joints.

The final mechanical properties of hot stamped components are affected by many process and material parameters due to the multidisciplinary nature of this thermal-mechanical-metallurgical process.
The phase transformation, which depends on the temperature field and history, determines the final microstructure and consequently the final mechanical properties.
The thermo-mechanical properties of the tool material AISI H11 are reported in Table 1.
The thermo-mechanical properties of the tool material AISI H11 [4].
Therefore, the oxidation levels of the blank, the part positioning, air velocity and the ambient temperature become important factors in the real production process.

In these applications, a full characterization of their mechanical properties including compressive strength and elastic modulus, at a wide range of strain rates is needed.
However, the most important factor affecting the compressive strength is its inhomogeneity, particularly the number and size of the non-uniform cells which result in local density lower than the average valued measured for the whole specimen.
A previous study suggested that, to evaluate effectively the mechanical properties of foam materials, the length of a specimen should be firstly determined.
Two factors may contribute to such phenomenon: friction effect between the specimen and bars and existence of weak deformation bands.
Two factors, which may contribute to such behavior, were presented.

The method of stabilisation and reduction has been based on active synthesis, which makes it possible to obtain the desired mechanical effect through the proper selection of dynamic properties of the system, including the calculation of the active force as a function of the system force feedback.
The method of reduction has been based on active synthesis [4 - 7], which makes it possible to obtain the desired mechanical effect through the proper selection of dynamic properties of the system, including the calculation of the active force as a function of the system force feedback.
These requirements apply to obtaining the set dynamic properties of systems with control as characteristic functions (impedance, mobility).
Therefore, if we take a frequency string in the form of: poles: , , ; zeros: , , then the function describing dynamic properties of the vibrating discrete system can be represented in the form of dynamic flexibility: , (1) or immobility (mechanical impedance): , (2) where: , - any positive real number.
Dynamic characteristics of a system subjected to active synthesis - reduction of the first resonant frequency of the system The value of amplification factors of the control system is determined by comparing the characteristics (3) with the characteristic of dynamic flexibility of the control system in the feedback loop in the form: , (5) where: – are transfer functions between the j-th input and first input of the analysed system in Fig.1; - are transfer function of the controller in the force feedback loop from the i-th movement.

A strategy is proposed to cope with combined thermal fatigue and hot corrosion resistance affecting industrial coatings.
It uses a thermo-mechanical model combining the heat transfer conditions, thermal and mechanical properties of the materials and the system geometry.
Other factors may lower the capacity of these layers to protect the substrate against corrosion [17].
As in T2 cycles, the layer reduces the overall fN , the superficial mechanical properties are necessarily less favourable than the steel ones.
The Ti and oxide layers mechanical properties are not taken into account as their properties are not well documented enough.

Meanwhile similar material matching program with 5 factors and 6 levels was designed by using Uniform Design Method.
And the physical and mechanical properties of the similar material compressive strength was measured under different proportions circumstances.
According to the requirement of the similar material, choose the basis of similar material: (1) The main mechanical properties of model is similar to simulative coal body, (2) In the process of experiment material mechanical performance is stable, not easily affected by environmental conditions, (3) Change the ratio of material to adjust some properties of the material to adapt the requirements for similar conditions, (4) Manufacture is convenient, solidification time is short, (5) The cost is low, abundant sources.
The main properties of raw materials are shown in Table 1.
And similar material matching program with 5 factors and 6 levels was designed by using Uniform Design Method; (2) The physical and mechanical properties of the similar material compressive strength was measured under different proportions circumstances.