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Quasi-close Loop Control of NC Machine Tools Qianqian Wanga, Yihui Fengb , Yulin Wangc School of Mechanical & Automotive Engineering, Hefei University of Technology No. 193, Tunxi Road, Hefei, Anhui 230009, P.
The main factors affecting the control accuracy of open loop NC systems are as follows.
One is the mechanical transmission error, the other is the step losing error of stepping motor.
The fixed compensation methods used by open loop control system are not very effectual for overcoming the elastic deformation and clearance of mechanical transmission system.
This property is very ideal for economical NC lathe.

Fig. 1 Device of ultrasonic polishing without abrasives Fig. 2 Mechanical model of processing systems Analysis of the Working Conditions of Tool Head The mechanical model of processing system in the process of ultrasonic polishing without abrasives may be simplified as Fig. 2 when the influence of stiffness of machine tool may be ignored.
While when the resonance caused by various kinds of interference factors in the work piece system and tool system occurs, the tool head will separate from the work piece, and chatter will occur in the surface of the work piece, surface quality will worsen, and the machining process will be unstable
Preload is a constant, while dynamic positive pressure is decided by ultrasonic vibration of tool head and a variety of random factors including random vibration of processing system, fluctuation of surface micro geometry morphology and uneven work piece material, etc.
The processing parameters in the process of ultrasonic polishing without abrasives will affect the surface quality and manufacturing efficiency directly, and leads to the change of metal deformation, friction properties and others, so as to lead to the wear of the tool head.
Acknowledgments Financial supports from Mechanical Engineering First Class Key Discipline of Henan Province, P.

Introduction Composite coatings has attracted extensive attention in the surface engineering, because it can bring matrix material with new performance such as abrasion, heat resistant and good anticorrosion properties[1-5].
Generally, by adding one or a few types of insoluble ceramic particles(mainly oxides and carbides powders) into electrolyte during electrodepositing, the particles added can co-deposite with matrix metal and the amount of particles incorporation affects the microstructure and properties of electrodeposited coating[1].
Generally, Al2O3 powder is among the particles with many advantageous properties, which is often used as a second phase to strengthen composite materials [3].
Consequently, jet electrodeposition is advantageous comparing to other electrodeposition methods based on the following factors.
Based on above analysis, these factors eventually lead to consolidated compactness of composite coating microstructure.

The properties of the coolant in MCHS are important to the heat transfer performance.
The effective thermophysical properties of the nanofluid are calculated using the following equations: Density (5) Heat capacity (6) where the subscripts ‘eff’, ‘p’ and ‘f’ refer to the nanofluid, particle and fluid respectively.
Full properties of the nanofluids are tabulated in Table 1.
Table 1 Thermophysical properties of nanofluids and particle volume concentration at pumping power of 0.05 W Nanofluid ρ [kg m-3] Cp [ J kg-1 °C-1] k [W m-1 °C-1] µ [kg m-1 s-1] ϕ=1% Al2O3-water 1027 4046 1.1567 0.000919 CuO-water 1050 3927 1.1333 0.000996 TiO2-water 1029 4038 1.1167 0.001060 ϕ=2% Al2O3-water 1056 3921 1.6525 0.001004 CuO-water 1103 3700 1.5790 0.001142 TiO2-water 1060 3906 1.4937 0.001394 ϕ=5% Al2O3-water 1146 3586 2.7569 0.001490 CuO-water 1263 3134 2.4147 0.001991 TiO2-water 1155 3554 1.8961 0.004485 Results and discussion Based on the governing equations, the main factors affecting the cooling performance of MCHS are thermal conductivity, dynamic viscosity and thermal capacity of the nanofluids.
Wu, Heat transfer properties of nanoparticle-in-fluid dispersions (nanofluids) in laminar flow, Int.

Friction has a relationship with the rolling force and its distribution, it affects the roll gap and roll wear significantly.
The mechanical properties of oxide scale are attributed to temperature [7-8].
The deformation or fractures of oxide scale affect the roll-strip interface behavior significantly [6].
A number of factors, including porosity, oxide scales present in the layer, and the chemical composition of the steel influence the formation of wustite [11], determine the strength of the oxides scales and therefore the coefficient of friction.
Short time oxidation tests were conducted on Gleeble 3500 thermo-mechanical simulator.

It is the guarantee of obtaining high-quality prints to maintain the stability,uniform and appropriate of the ink transmission and merastasis.As a key technology that ink transfer affecting print quality will attract people's attention increasingly.
There are many factors what can affect the ink transfer, such as printing substrates, printing pressure,printing pressure and so on.
As a matter of fact, the ink performance is also an important factor, however, there are no so many researches about it.
With the influence of different factors, the ink-transferring ratio will decrease when the proportion of viscosity reducer is more than 6%.
Feng: Journal of Henan Mechanical and Electrical Higher Professional School, (2008)No. 6

Bearing system’s multi-flexible rigid-flexible coupling modeling 3.1 Modeling method for flexible body in ADAMS There are mainly two methods for building flexible body in ADAMS: 1) Discrete Method, i.e. to divide the ADAMS rigid model that has certain geometric entity into several entities block, and define each one’s mechanical properties, use flexible beam joint to build ADAMS flexible body between the separated small rigid members; 2) Import Modal Neutral File Method, i.e.
Define material properties and boundary conditions According to the characteristics of bearing outer ring to fix the contact surface between the bearing outer ring and the bearing pedestal, and impose torque in the bearing inner ring.
Coal mine mechanical and electrical, 2009, (2): 7 - 9
Mechanical Dynamics Inc. 2000
Mechanical science and technology, 2002, 21(6): 892 - 895

Among the Sn-Ag-Cu solder alloy family, SAC305 solder powder has been accepted as the most promising and used instead of tin-lead solder alloy due to its relative low melting point, excellent mechanical properties and solderabilities [3].
For centrifugal atomization method, many processing parameters affect the liquid droplets.
One of the most crucial factors for energy transfer is wettability between the disk and the melt.
The results show that oxygen content in the chamber directly affected the amount of oxygen on the powder surface.
Suganuma, Effect of intermetallic compounds on properties of Sn-Ag-Cu lead-free soldered joint, J.

The chemical-mechanical polishing, electro-rheological fluid polishing, and magneto-rheological fluid polishing methods can be satisfied those demands for the high polishing accuracy and surface roughness.
Advantages of ERF and MRF Chemical-mechanical polishing (CMP), a process involving more chemical reactions than the conventional process, has been applied for a wafer planarization in IC fabrication.
Although the viscosity of ER fluid depends on a number of conditions and properties, it can be simply modeled as Bingham fluid with the assumption that it satisfies the equation (1) in laminar flow. )(Ey���� += & , (1) where � is shear stress, �& is shear rate, � is viscosity, and )(Ey� is yield shear stress of ER fluid.
One of major influencing factors in determining polishing characteristics is the intensity of electric field, because it seriously affects the shear rate.
Lee: Proceedings of Korean Society for Mechanical Engineering, Vol. 1 (2000), p. 597

Different laser parameters and the resultant can affect the barcode grade profoundly.
He found that contrast and print growth factors limited the laser mark achieving a higher grade.
It can get the deeply understanding and knowledge about the connection among laser parameters and substrate properties with barcode quality.
Conclusions The experiment results and analyses show that the microstructure and micro-components of formations that created by the interaction can affect the barcodes grade level significantly and determine the barcodes grade level
Li: Metal Metallographic Map (Mechanical Industry Press, Beijing 2006)