Search results

Main part A wide-spread approach for disaggregated materials analysis is represented by three-dimensional modeling of the properties and structure with solid spheres application.
Such aggregates and the very particles affect the properties of powders in a far different manner.
Both separate powders and their mixtures are characterized with the same solution rapidness and the time of saturation of solutions under given conditions. 667 m2/kg- 0% 667 m2/kg- 15% 667 m2/kg- 30% 667 m2/kg- 45% 667 m2/kg- 60% 667 m2/kg- 75% 667 m2/kg- 100% 667 m2/kg 753 m2/kg 847 m2/kg 892 m2/kg 919 m2/kg 987 m2/kg 1006 m2/kg a) b) Fig. 6 a) Kinetics of saturation of calcium hydrate sulfate powdery solutions with different degree of fineness b) Kinetics of saturation of solutions of bi-dispersive mixtures of powders of calcium hydrate sulfate with various percentages of more coarse powder With the purpose to study physical and mechanical properties the specimens have been moulded by way of semidry pressing on a lab hydraulic press.
Granularity regulation and hydrate gypsum fineness increase are the basic factors to manufacture high-performance gypsum rock and high quality of materials and products on its basis.
Geom., 41 (No. 2, 2009), 232-248; [2] Petropavlovskaya V.B.; Belov V.V et al.2008.Regulation properties unburned refractories was started gypsum materials, Building materials.

Béreš1,f 1 Federal University of Ceará - UFC Department of Materials and Metallurgical Engineering Campus do Pici, Bloco 714, CEP 60455-760, Fortaleza, CE, Brazil 2 Federal University of Fluminense - UFF Department of Mechanical Engineering, Rua Passo da Pátria 156, Bloco E, CEP 24210-240, Niterói, RJ, Brazil ahamilton@ufc.br, bwellisonst@yahoo.com.br, chmiranda@ufc.br, dmcindra@vm.uff.br, ehenrique_neto_ja@hotmail.com, fberesm@metalmat.ufc.br Keywords: welding, residual stress, toughness, martensitic transformation, low transformation temperature Abstract: Residual stresses in welded components are consequence of stress and/or thermal gradients and influenced by factors such as joint geometry, variation in strength of the material, preheat temperature, heat input, post-weld heat treatment and phase transformation strains.
Introduction Residual stresses in welding are results of stress and temperature gradients caused by factors such as joint geometry, heat input, post-welding heat treatment, preheat temperature and phase transformation.
In the heated affected zone (HAZ) tensile longitudinal residual stresses were identified.
Nakamura, Superior fatigue crack growth properties in newly developed weld metal, International Journal of Fatigue, (1999), 21, 113-118 [5] J.A.
Withers, On the evolution of local material properties and residual stress in a three-pass SA508 steel weld, Acta Materialia, (2012), 60, 3268-3278 [8] J.

Introduction Heat pipe is a type of high efficient heat transfer component which can transfer the heat out of the heat source rapidly by fully using the heat conduction principle and the refrigerating medium’s rapid heat transfer property.The heat pipe technology has been widely used in the fields of aerospace, military industry etc[1,2].
Some researchers have studied the using of heat pipe for cooling the mechanical processing zone [3-5].
During the grinding process, mechanical work is converted to heat through the plastic deformation involved in chip formation and through friction between the wheel and the work-piece.
The heat transfer capacity of the heat pipe mainly depends on two factors, the state of the liquid membrane and the speed of the heat circle.
The processing parameters such as the rotating speed and the liquid filling rate are all greatly affect the heat transfer performance of the heat pipe in the heat-pipe grinding wheel.

Therefore, the factors that affect product quality were more complex, and the machining accuracy requirement increased day by day.
For the mechanical equipment, the failure rate(), mean time between failures(MTBF), availability(A) and others
For the mechanical equipment, the maintain rate, the average maintenance interval and others
(4) Security (Y4): It referred to an ability of the equipment to reflect the casualties and the property loss, which was led by poor product quality in the storage stage, or distribution stage, or use stage
References [1] Chenxian Yang et al, Theory and Technique of Quality Control in the Production Process of Mechanical Equipment, National Defense Science and Technology Press, Beijing ,2007

One of the ways to improve the thermal performance of heat pipes is to change the fluid transport properties and flow features of working fluids using nanofluids.
The fluid charging ratio also affected the heat pipe thermal resistance, where the smallest thermal resistance was found when the fluid charging ratio was 60%.
Do et. al [10, 19] presented that the key effect of heat performance improvement of a heat pipe is not only on their thermophysical properties of nanofluids but the larger is the thin porous coating layer formed by the nanoparticles on the surface of nanofluids in heat pipe wick.
However, this was predicted as a other factor for enhancement of sintered wick heat pipe performance charge with nanofluid.
The increased concentrations of nanofluid affected the reduction of the thermal resistance of heat pipe.

The analysis of motion and mechanics property was carried out on the five hinged incline arranged and double elbowed force increasing mechanism of injection machine.
A few changes of the design parameters may increasingly affect the unitary performance of products.
But the limitation of injection power and other factors should be involved.
motion and mechanics property of force increasing mechanism greatly.
Consequently, motion and mechanics property of force increasing mechanism of injection machine is improved, which allows to use lower power to obtain higher efficiency.

Introduction The phenomenon of arthritis is a degenerative joint disease believed to result from a combination of mechanical loading factors and biological weakening of the cartilage matrix.
Knowledge of the mechanical properties of the interface is essential in understanding the mechanism leading to failure and are still far from being well-documented.
In a subsequent study, Nuño and Avanzolini [3] have shown using a numerical model that inclusion of the residual stresses due to cement curing affects the cement stress distribution at the stem-cement interface.

Servo aimable warhead is that use of the mechanical structure of the warhead with the implementation of automatic control.
This warhead fast response, and can play a role in orientation, but there are still a lot of shortcomings[2] the secondary explosions hard not affect the main charge, security, and accuracy is not high.
Servo System Control Algorithm Research Status Performance servo system is a major factor in determining the effect of the warhead damage, and the control algorithm determines the performance of servo systems.
[4] Robust Control, the so-called "robustness" means a control system (structure, size) of the perturbation parameter, maintaining the characteristics of certain properties.
Journal of Mechanical Science and Technology, 2012, 26(4): 1146-1159.

Comparison between Nitrogen- Oil- Mist and Air-Oil- Mist Condition when Turning of Hardened Tool Stainless Steel Mohamed Handawi1,a, Amad Elddein Elshwain1,b, NoordinMohdYusof*1,c, Norizah Redzuan1,d, Denni Kurniawan1,e 1Faculty of Mechanical Engineering, University Teknologi Malaysia, Skudai, Malaysia aelmunafi@gmail.com,belshwion@gmail.com, cnoordin@fkm.utm.my,dnorizah@mail.fkm.utm.my, edenni@utm.my Keywords: Nitrogen gas, MQL, Stainless Tool Steel, Surface Roughness, and Tool Life Abstract.Minimum quantity lubrication (MQL) is a technique which sprays a small amount of lubricant to the cutting zone with the aid of compressed air.
The normal chemical composition and mechanical properties of stainless tool steel (STAVAAX ESR) are (C 0.38%, Si .9 %, Mn 0.5%,V 0.3%, and Fe Balance), Hardness 48 HRC and yields strength 1280Mpa respectively.
In Fig. 5 crater wear area for nitrogen-oil-mist condition was less than air-oil-mist condition, whereas air-oil mist condition, the crater wear area was burned which means the nitrogen gas played significant factor to reduce the temperature at cutting zone.
iii) Nitrogen gas playsa significant factor to reduce the temperature at cutting zone.
iv) Surface roughness could be significantly affected by nitrogen-oil-mist especially at high speed than air-oil-mist condition.

This determines the final microstructure and thereby the mechanical properties of the material.
The energy of the interfaces depends, among other factors, on the difference in crystallographic orientation between neighbouring grains and on the inclination angle of the interface between the two crystals.
Unfortunately, duplex stainless steels also contain carbon, which tends to form carbides with the chromium present at austenite grain boundaries, which may affect the nucleation of the ferrite phase.
The samples were prepared for the EBSD measurements by mechanical (down to 1µm) and electrolytic polishing (electrolyte A2 (Struers), flow rate 13, 25 s, 35 V).