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Silberschmidt1d 1Loughborough University, Wolfson School of Mechanical and Manufacturing Engineering Loughborough University, Leicestershire, LE11 3TU, UK 2 Department of Mechanical Engineering, Taibah University, Saudi Arabia aR.Muhammad@lboro.ac.uk, bDr.N.Ahmed@hotmail.com cyshariff@taibahu.edu.sa, dV.Silberschmidt@lboro.ac.uk Keywords: Conventional drilling, hot drilling, Ti alloy, finite element, thrust force, torque.
Abstract Demand for high-strength alloys in aerospace, marine and off-shore industries has grown significantly over the last decades, primarily thanks to their high strength, light weight as well as good fatigue and corrosion-resistance properties.
Fig. 3: Material model for Ti-6Al-4V [10] The material properties of Ti-6Al-4V are ν = 0.3, ρ = 4430 kg/m3, where ν and ρ are the Poisson's ratio and density of the material, respectively.
The model incorporates a shear friction factor: μ=τfks, (1) where ks is a shear flow stress of the workpiece material at the tool-chip interface and τf is frictional shear stress [15,16].
The torque during drilling process is also affected by the amount of external heat supplied to the workpiece in HD.

Since structural damage affects the stiffness distribution, the presence of the fault will change the dynamic properties of the structure under analysis, i.e., natural frequencies and mode shapes.
Most of the mode shapes-based methods that have been discussed above can also use other structural dynamic properties as input data.
The normalization factor is given by (8) The constraints in Eq. (6) guarantee this normalization factor to be non-zero.
When the remainder of the Taylor expansion is divided by the scaling factor , a high order of convergence is achieved in the smooth regions.
Violaris, Numerical investigation of a new damage detection method based on proper orthogonal decomposition, Mechanical Systems and Signal Processing 21 (2007) 1346–1361

Optimal grain refinement thus appears to be a compromise between several competing factors: large strains at relatively low temperatures for high dislocation density, higher temperatures to enable sufficient dynamic recovery, and low grain boundary mobility that is aided by low temperatures and/or pinning by solute atoms or second phase particles.
The reasons for the growing interest in such materials lie in an interesting combination of desirable engineering properties, such as combined high strength and ductility [1], superplasticity at moderate temperatures and high strain rates, and improved recyclability owing to the lessened need for heavy alloying.
Much of the emphasis thus far has been on the characterisation of mechanical properties and qualitative microstructural observations of UFG materials [7,8].
Indeed, SPD-induced HAB have been reported to be in "non-equilibrium" configurations, possessing defect structures that are thought to be responsible for several of the remarkable properties of UFG materials cited earlier (cf.
Thus, the conditions for optimal grain refinement appear to be a compromise between several competing factors: low temperatures for high dislocation density and low grain boundary mobility, and high temperatures for large strains and dynamic recovery.

Review of the Development of Dry Coal Preparation Theory and Equipment Hai Lin Dong1, Chu Sheng Liu1,3, Yue Min Zhao2,3, La La Zhao1,3,* 1School of Mechanical and Electrical Engineering, China University of Mining & Technology, China 2School of Chemical Engineering and Technology, China University of Mining & Technology, China 3Key Laboratory of Coal Processing and High Efficient Cleaning & Utilization of Ministry of Education, China zll_xz@163.com Keywords: dry coal preparation; screening theory; screening equipment; flip-flow screen Abstract.
The results show that the moist fine materials have complex physical properties and the theory of dry deep screening needs further improved.
According to the reaction mechanism between particles and water, Hollinderbaumer and Hoberg[5] proposed ways of heating screen surface and adding water absorption to overcome hole plugging, which was evaluated to be a high production cost, a unsatisfied screening effect and low mechanical reliability.
The researchers firstly studied damp granule of coal on the adhesion mechanism, pointed out that the external water is a screening process of fine grained primary factors of coal adhesion, and set up wet adhesion model for fine-grained materials[9].
The liquid bridge force between wet particles can cause the material reunion phenomenon, which is the main factors affect particles activity, and widely attracted the domestic and foreign researchers’ attention.

In rheo forming process, slurry making is very important factor because the microstructure of slurry affects the quality of final products.
Finally, to find out mechanical properties of grain controlled aluminum part by rheo die casting, tensile tests were carried out to the T6 heat treatment.
It is reported that semi-solid forming process has many advantages like longer die life, good mechanical properties and energy saving compared to the conventional forming process [1-2].
Also, mechanical properties were investigated according to the experimental conditions.
properties were investigated through tensile tests.

Experiments on NH3/H2O falling film absorption with external magnetic fields were studied by Niu etc[2,3], and proved the change of properties in solution by magnetic field.
For seeking for the effect mechanism of magnetic field on ammonia bubble absorption, the relevant experiments in external magnetic field were conducted and the magnetic field intensity and ammonia concentration were considered as the key influencing factors.
Ammonia bubble absorption is a process of mass and heat transfer, which has a great relationship with the solution properties.
According to the relevant research [5], magnetic fields have an impact on properties of ammonia solution.
The physical properties of ammonia can be affected by the magnetic field which can decrease the ammonia surface tension and the viscosity.

This, among others, results from a number of factors that influence the process and their mutual relations.
The properties of the composite coatings are determined by the type and structure of the metallic matrix as well as the type and size of the built-in particles.
As a result of the interaction of the matrix with the components, a set of properties different from the properties of the starting materials is formed.
This review also deals with the phenomena related to the electrochemical properties of the composite electrocatalysts towards hydrogen/oxygen evolution.
This process determines the properties of the obtained materials.

Introduction Titanium alloys are used widely in aerospace industry due to their good properties, such as light-weight, high-strength, little galvanic corrosion, etc [1].
Machlin [4], in 1959, concluded that electricity affected flow stress, ductility, and yield strength of a NaCl salts significantly.
Karunasena [8] indicated that the current density, environmental temperature, wind velocity, cross-sectional area and length of the sheet are the key factors for the sheet heating velocity.
Mechanical property change.
To investigate the effect of the above process conditions to the mechanical property of the Ti-6Al-4V, the uniaxial tensile tests were conducted.

During excavation of underground caverns and slopes, property and strength of rock masses changes and excavation disturbed zone (EDZ) forms with the combined effects of rock mass unloading and blasting vibration etc.
EDZ is an important factor to the deformation and stability of underground caverns and slopes.
Moreover, affected by geological structure of this region, Valley development history and geo-stress, deep cracks are well developed between EL. 1700 m and 1900 m [2-4].
Rational selection of mechanical parameters of rock masses and discontinuities is critical for the numerical simulation by finite element method.
According to mechanical parameters suggested by Hydrochina Chengdu Engineering Corporation [1], mechanical parameters of rock masses and discontinuities used here are shown in Table 1.

There are significant efforts dedicated to the research and development the PTFE braided composite using different fibers and fillers possessing high mechanical properties and temperature stability and also maintaining low coefficient of friction [3].
Thermal stability in the friction and wear properties are the main causes, and the tribology performance and service life is mainly affected by the friction temperature, especially in the working conditions of the high apply loads and high swinging frequency[6,7].
This result can reduce the anti-wear properties of the composite material.
Effects of friction heat on the tribological properties of the woven self-lubricating liner [J].
Tribological properties of transfer films of PTFE-based composites[J].Wear, 2006,261 (11-12): 1359-1366