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Study on Computer-aided Optimizing Milling Parameters of Numerical Control Machine Zhao Yu-xia1, a , Xu Hong-hai 2, b , Gao De-wen 3,c 1,2College of Mechanical and Electrical Engineering, North China University of Technology, China 3 No.5 Jinyuanzhuang Road, Shijingshan District, Beijing, P.R.
Introduction Selection of milling parameters is one of the key factors that affect the product quality and productive efficiency during NC machining process.
Milling parameters, such as spindle rotation speed, cutting depth and width, are more important active factor in NC milling process and different combination of them would have different outcome.
Due to the uncertain or random factors such as change of the material properties, abrasion of the tools, heating deformation, etc, would affect the working conditions, subsequently would affect the optimization results.

Yet, they have limitations like high friction coefficients and low wear resistance, affecting energy efficiency and the lifespan of advanced machinery.
In this study, micro-grooves in a grid array were textured onto Ti6Al4V surfaces to improve their tribological properties.
Summary This study demonstrates that laser texturing significantly improves the wear properties of Ti6Al4V alloy.
Hu, “Study on the surface properties and biocompatibility of nanosecond laser patterned titanium alloy,” Opt.
Kusý, “The Influence of the Tool Surface Texture on Friction and the Surface Layers Properties of Formed Component,” Adv.

In recent years, much effort has been spent by several research groups worldwide to provide a deeper understanding of process effects on mechanical properties, microstructure, and residual stress induced by the process [3-8].
The following step is to realize a crack propagation analysis, with the stress intensity factors (SIFs) and crack growth rates calculated by DBEM, based on the chosen crack propagation law (Eq. 2).
Nogi, Tensile properties and fracture locations of friction-stir-welded joints of 2017-T351 aluminum alloy, J.
Withers, Microstructure, mechanical properties and residual stress as a function of welding speed in aluminium AA5083 friction stir welds, Acta Mater. 51 (2003), 4791-4801
Palazzo, Influence of Process Parameters on Microstructure and Mechanical Properties in AA2024-T3 Friction Stir Welding, submitted to J.

The samples of carbon steel with lower maximum depth of valleys (Rv) showed the best protection properties compared to other samples.
HSLA steels exhibit unique properties: high strength, high forming property, good weldability and very positive low-temperature impact strength, which is higher than for steels with high yield strength.
Beyond these properties, for several applications a correct surface treatment is important to increase resistance against aggressive environments [1, 2, 3, 4, 5].
These factors cause reduction in load carrying capacities of steel members and thereby causing subsequent failures [8].
Northwood: International Mechanical Engineering Congress and Exposition ASME.

The accuracy of the theoretical prediction of the fatigue life is dependent on both the correct simulation of the stress-strain response, and also depends on the reasonable use of the damage model; the fatigue life is also related to a variety of factors such as load, temperature, surface roughness and residual stress.
The analysis of the fatigue life is determined by the load history based on the fatigue properties of the material, control structure, according to the analysis model to determine the fatigue life of the structure.
Conclusion The gear fatigue is a complex process, affected by a variety of factors, the ability can accurately predict the fatigue life of the gear, and you need to select the appropriate model.
Currently, the gear fatigue life problems and trends are as follows: Due to the fatigue problem involving many factors considered in the course of the study, only one or two kinds of main factors, simplified and model made larger, resulting in large deviation calculation results with the actual life.
As much as possible the impact of factors into how to gear fatigue life model, the problem of a long stage.

Studies on Mechanical Properties, Fracture morphology and Corrosion behavior of Pulsed MIG welded AZ31B Magnesium Alloy sheets Gurusamy Viswanathan 1,a *, Pitchandi Kasiviswanathan 2,b, Muthukrishnan Nambi 3,c 1Welding Research Cell (WRC), Department of Marine Engineering 2,3 Department of Mechanical Engineering, Sri Venkateswara College of Engineering, Pennalur, Irungattukottai(PO), Sriperumbudur Taulk, Tamil Nadu, India-602117.
Introduction Magnesium and its alloys are prospective candidates to substitute steel and aluminium alloys in many structural and mechanical applications, owing to some of their unique properties like low density, high specific strength and stiffness, high damping capacity, good castability and recyclability.
A crucial factor in MIG welding of magnesium alloy is the energy input into the filler wire.
The macro structure, mechanical properties and corrosion property of AC p-MIGW of AZ31B magnesium alloys plates are investigated.
(3) (3a) (3b) (3c) Fig-3 Macro analysis and Micro hardness test specimen, Fig-3a Microphotography Welded Mg alloy for 140 A, Fig-3b Microphotography Welded Mg alloy for 150 A, Fig-3c Microphotography Welded Mg alloy for 160 A Mechanical Properties of the joints Micro hardness test The micro hardness test was taken at every 1mm on the weld area both in longitudinal and transverse direction.

The performance of the synchronizing ring directly affects the reliability and safety of the transmission system[1].
The theoretical foundation for the rigid visco-plastic property finite element is the Markov variational principle.
The shear model is used to act as the friction boundary condition, namely, (14) In the formula: is the shear friction factor and is supposed 0.3; k is the shear yield strength.
However, precision forging process of synchronizer ring is high temperature and large deformation, there is heat transfer on billet-die interface, simultaneously plastic work and frictional work turn to heat, all these factors make temperature filed of billet continually change, the change of temperature field will affect deformation behavior of billet, furthermore affect the mechanical capability and microstructure of synchronizer ring.
Hu: China Mechanical Engineering.

The main characteristics of these materials lie in the graphite particles inclusions whose morphology and count greatly influence the mechanical properties and more specifically the fatigue crack initiation and propagation behaviour of the SGI components.
These unique properties of SGI are attributed to the nodular graphite form, which helps to minimize the stress intensification effect around the graphite nodules and improves the mechanical and fatigue properties of the material [1, 2].
With superior mechanical and fatigue properties, SGIs are undoubtedly better when considering fracture and fatigue.
The sample material was cast in the form of a 50 mm thick cast plate, and had the mechanical properties of Young’s modulus E = 170 GPa, yield stress σy = 410 MPa, ultimate tensile strength UTS = 510 MPa and elongation = 17 %.
It seemed that the interface strength was not affected during the initial 16 thermal cycles.

Physical and mechanical properties of LDPEs.
Concentration and processing time are factors that influence fiber quality.
IV Conclusion The mechanical properties of composite materials determine their field of application.
A thorough understanding of these mechanical properties is essential.
Tajvidi, « Mechanical properties of composites from sawdust and recycled plastics », J.

The fracture-mechanical parameter values of concrete, a quasi-brittle composite material, are determined via evaluation of records of experiments on specimens with stress concentrators.
This model combines the concept of cohesive forces acting on the effective crack increment with a criterion based on the stress intensity factor.
Even relatively small volume quantities of these fibres in concrete mixture can affect the resistance of the composite to crack propagation.
Results The relative mean values of selected material properties (compressive strength fc, modulus of elasticity E, effective crack elongation ac – a0, unstable fracture toughness KIcun, and ratio KIcini/KIcun) are introduces in Table 1 (normal weight concrete) and Table 2 (lightweight concrete): the 100% value for each material parameter represents the values of those parameters for the reference concrete without fibres OB_REF respectively LB_REF.
In Table 3 the same parameters are introduced, but the 100% value represents the value of material properties for normal weight concrete.