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The plasma nitriding process is one of the basic chemical-heat treatment processes used to improve the mechanical properties of structural steels.
However, there is rarely a direct relationship between salt spray resistance and corrosion resistance in other environments, because individual factors affecting corrosion, e.g. the formation of protective layers vary considerably in specific conditions.
Evaluating and judging the appearance of samples depends on subjective factors.
Plasma nitrided structural materials of higher classes show better anti-corrosion properties compared to lower classes of steels such as material 11 373.
[8] Dong-Cherng Wen, Plasma nitriding of plastic mold steel to increase wear and corrosion properties.

As the portable exoskeleton system functions as an assistant device for human body weight-bearing exercises, human factors must be taken into account in designing of the mechanism, which are design constraints brought about by the upper limit of human body weight-bearing capacity and human body size.
As the most important parameter that affecting the particle speed renewal, the inertial weight ω directly performs control over speed and direction.
To set the appropriate material properties in ANSYS, select the SOLID92 units, and assign the corresponding element attributes for each component in the mechanical structure of portable exoskeleton, the finite element model can be obtained, as shown in Fig. 2.
Mechanical Science And Technology. 2007,26(8):1063-70
Beijing: Mechanical Industry Press;2008.

In terms of quality product it is considered any deviation (of dimensions, shape compactness, weight, appearance, macro and microstructure, mechanical parameters and other variables) from properties prescribed by technical standards, specifications or agreed conditions.
Fig. 12 SeparatedparticlesAl2O3 Fig. 13Grouping of particles Al2O3 The effect of particles Al2O3to reduce the mechanical properties is greater than the effect of bubbles.
The oxidation can also occur by using the moist, imperfectly dried molds when there is the emergence of oxygen capable of the metal oxidizing.During mere casting it should be proceeded to avoid the large metal turbulence and its secondary oxidation.[3, 5] Chemical Composition Defects, Incorrect Physical or Mechanical Properties Incorrect chemical composition, properties deviations, non-observance of mechanical values from the agreed specifications or standards.
These factors represent a set of mutual ties that are interacting.
References [1] Gašpár, Š. - Paško, J.: Influence of technological factors of die casting on mechanical properties of castings from silumin, Lecture Notes in Electrical Engineering, Vol. 240, 2013, p. 713-722 [2] Gašpár, Š. - Paško, J.: Metal flow velocity in an intake port in the process of die casting, Advanced Materials research, Vol. 705, 2013, p. 177-180 [3] Paško, J. - Gašpár, Š.

Abstract The process of implementing a damage identification strategy for aerospace, civil and mechanical engineering infrastructure is referred to as structural health monitoring.
The process of implementing a damage identification strategy for civil and mechanical engineering infrastructure is referred to as structural health monitoring.
The American federal emergency management agency carried out a range of research in welded steel frame structure in Lomaprieta earthquake in 1989, in Northridge earthquake in 1994 and Hyogo-kenNanbu earthquake in 1995, they released the report of the buildings safety and earthquake resistances. 3.The projects and contents of steel structures monitoring 1) material performance It needs test the current situation of steel material performance, including [5]: (a) the mechanical properties of steel structures material;(b) the chemical composition of steel structures material;(c)the metallographic of steel structures material;(d) the physical properties of steel structures material; (e) the surface quality of steel structures material;(f) the welding materials of steel structures; (g) the protective materials of steel structures. 2) the corrosion parts of steel structures (a) the near site underground; (b) the site might be watered;(c) the site lies in wet and dry seasons environment
(4)Genetic algorithm Genetic algorithm can quickly decide the location and degree of structural damage under few information, even if the parts of modal information lose, the optimal capacity can’t be affected.
At the same time, the testing and monitoring of steel structures are important decision of disaster prevention and alleviation in China, it can define insufficient bearing capacity or unsafe structures from the source, we can strengthen them as soon as possible, so it can reduce the damage of human factors and nature, and minimize people's life and property loss and safeguard social stability.

They produce a large number of wear particles which resulting in aseptic loosening and affecting the life of joint [3].
Friction factor.
The friction test was done in the ring-block friction and wear test machine, MHK-500, with the 40# lubrication, The friction factor was measured by LPDZ3 dynamic testing instrument and calibrated by the mechanical lever force-measuring device.
This experiment shows that the friction factor of nano-ZrO2 ceramic test block against GCr15 steel test ring, whose fiction factor is 0.084, is less 37.3% than that of 45 # steel block against GCr15 steel ring, whose fiction factor is 0.134, which indicates that the nano-ZrO2 ceramic has better tribological properties than 45 # steel.
Wear property.

The welding speed does not present a significant effect on the joint mechanical behaviour using the optimized parameters.
The relationship welding parameters, micro hardness, micro structure and tensile properties are investigated to evaluate the quality of the joint.
Two factors are important to get a relatively higher tensile strength.The presence of fine, prefect, without any defect in microstrucure are essential to enhace the strength of the weld Zone. 4.
Roberto Frias, s/n 4200-465 Porto, Portugal [6] Yong Zhao ⇑, Lilong Zhou, Qingzhao Wang, Keng Yan, Jiasheng Zou, 2013, Defects and tensile properties of 6013 aluminum alloy T-joints by friction stir welding, Provincial Key Lab of Advanced Welding Technology, Jiangsu University of Science and Technology, No. 2 Mengxi Road, Zhenjiang 212003, Jiangsu, China
[7] Lei Cui, Xinqi Yang∗, Guang Zhou, Xiaodong Xu, Zhikang Shen, 2012, Characteristics of defects and tensile behaviors on friction stir welded AA6061-T4 T-joints, Tianjin Key Laboratory of Advanced Joining Technology, School of Material Science and Engineering, Tianjin University, Tianjin 300072, People’s Republic of China [8] Xiaopeng Hou, Xinqi Yang ⇑, Lei Cui, Guang Zhou,2013, Influences of joint geometry on defects and mechanical properties of friction stir welded AA6061-T4 T-joints, Tianjin Key Laboratory of Advanced Joining Technology, School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China

However, the relationship between scan speed, thermal behavior, and resulting material properties is complex and requires careful consideration.
Oxygen is a highly alphagen element, so contamination with oxygen and nitrogen can alter the solidification behaviour and phase transformations of Ti64, leading to undesirable microstructures and potentially compromised mechanical properties [6].
Powder physical properties analysis results.
The combined effects of porosity and microstructural variations can negatively impact tensile strength, ductility, fatigue life, and other critical mechanical properties [3].
It is crucial to understand how these treatments affect the microstructure and mechanical properties of Ti-6Al-4V processed by PBF-L/M.

Introduction As a good mechanical properties of the metal Titanium alloy has been applied in many fields.
To analyze the major factors that affect temperature field during the laser cladding, the paper builds a finite element model of temperature field of titanium alloys laser cladding in consideration of heat source model, material thermal physical property and meshing situation.
Material thermo-physical properties: The experimental substrate is TC4 titanium alloy, which nominal thermo-physical properties is shown in Tab.1,and the cladding layer powder material is mixtures of Cr3C2 powder and pure Ti powder.
The thermo-physical properties of Cr3C2 and Ti powder are shown in Tab.2 and Tab.3.
As the thermo-physical properties of material are of great influence on calculating temperature field ,which directly affect the shape and size of the laser cladding temperature field, it is necessary to take into account temperature dependency of the thermal properties of the material Table 1 Thermo-physical properties of TC4 titanium alloy melting points[℃]：1540~1650 density[kg/m3]：4440 T[℃] 20 100 200 300 400 500 600 800 1000 1400 1600 heat conductivity[W/(m•℃)] 6.8 7.4 8.7 9.8 10.3 11.8 12.4 14.4 15.8 24.3 22.2 Specific heat[J/(kg•℃)] 611 624 653 674 691 703 708 727 751 783 898 Coefficient of linear expansion[10-6/K] 9.0 9.0 9.0 9.0 9.0 9.4 9.4 9.7 9.7 9.7 9.7 Table 2 Thermo-physical properties of Cr3C2 specific heat [kj/kg·K] coefficient of linear expansion[10-6/K] elastic modulus[Pa] density [kg/m3] Melting points [˚C] heat conductivity [W/m·K] 0.3 6.74 0.355E11 6900 3530 19 Table 3 Thermo-physical properties of titanium melting points[℃]：1668±4 density:[kg

The performance of solid expandable tubular threaded joint is affected by complicated factors such as material property change, large deformation of geometric dimension and residual stress.
The working characteristics of the solid expandable tubular threaded joint are extraordinarily complicated, involving geometric three-dimensional nonlinear deformation, nonlinear change of material property, contact nonlinearity, and high residual stress level on the connecting part after deformation.
In this paper, by taking the structure of expandable threaded joint designed by the author as an example and focusing on the working characteristics of the solid expandable tubular threaded joint during expansion, working characteristics of the solid expandable tubular threaded joint under the effect of multiple factors such as geometric three-dimensional nonlinear deformation, nonlinear change of material property, contact nonlinearity and residual stress are explored to lay a foundation for the design and development of the solid expandable tubular threaded joint.
These factors inevitably have effect on the joint strength of joints for the existence of hardening and residual stress.
With the comprehensive effect of these factors, the joint strength of joints after expansion falls slightly.

The micro- structure, mechanical properties and wear resistance of the gradient composites were investigated.
And the microstructure, mechanical properties and wear resistance of the gradient composites with different WCP volume fraction are investigated in the paper.
The specimens of the composites for metallographic, wear and properties tests were cut off by line cutting method.
The mechanical properties were measured by an impact tester, a hardness tester and a universal tensile test machine.
Table1 Mechanical properties of the gradient composites Testing materials Tensile strength (MPa) Impact toughness (J cm -2) Hardness (HRA) Composites (70 vol.% WCP) Composites (54 vol.% WCP) High speed steel 345 460 535 4.6 6.2 3.5 81.0 78.2 83.5 μ 150μm μ 150μm Fig.1.