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Fractal Characteristics of Primary Phase Morphology in Semisolid A356 Alloy Zheng Liua, Xiaomei Liub Faculty of Mechanical and Electronic Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China a liukk66@163.com, b liuxm66@163.com Keywords：semisolid, primary phase morphology, fractal, A356 alloy Abstract: Semisolid A356 alloy was prepared by low superheat pouring and slightly electro- magnetic stirring(LSPSES).
Introduction The research has indicated that one of the microstructural characteristics in semisolid alloy with good forming properties has certain amount of non-dendritic primary phase in the alloy [1].
Discussion During formation and growth of the primary phase in the semisolid alloy, because of affecting by preparing condition and external physical field (for example pouring temperature, stirring power, stirring time, isothermal holding, ultrasonic or mechanical disturbance and so on), there will be change on the morphology and size for primary phase, at the same time, there is other change, included growth and migration of primary phase, even fuse and separation of primary phase to make primary phase morphology change.
There are the numerous complicated factors affecting the morphology during evolution of primary phase morphology in semisolid A356 alloy, in which they are nonlinear in essence.

The air-gap significantly affects the magnitude of heat transfer.
A numerical model has been developed to predict the size of the air-gap and the temperature distribution along the metal-mould interface given an initial Interfacial Heat Transfer Coefficient (IHTC), dependent on the mould surface roughness, and sufficient knowledge of the radiative and thermomechanical properties of the casting and mould materials.
Many factors can influence the IHTC including chill/mould material [3], alloy composition [4], alloy superheat [5,6], surface roughness [5], surface coatings [7,8], applied pressure [9], casting surface orientation [10], and the magnitude of the air-gap, which is known to rapidly decrease the IHTC [11,12].
Once the mechanical strength of the skin can withstand the pressure from the melt above, the shape of the ingot is retained.
The radiative heat transfer is un-affected by the air-gap size, so this leads to an increase in the qr/qc ratio.

Multi-linear regression models describing the relationship between mechanical properties and ultrasonic parameters were proposed and found to be a reliable method for predicting the mechanical properties of fruits.
The hardness (mechanical properties) of fruit is an essential factor affecting the physical property related to storage, processing, and quality control.
Ultrasonic technique is very useful for nondestructive measurement of the mechanical properties of materials.
The relationships between ultrasonic parameters and mechanical properties of fruit samples were analyzed.
It can be concluded that ultrasonic parameters can be used for estimating the mechanical properties of fruits.

The electrical properties of the probe under different loading frequencies Qing Yuan , Lei Han*, and Chunliang Liu State Key Laboratory of High Performance Complex Manufacturing and School of Mechanical and Electronical Engineering, Central South University, Changsha, 410083, China *Corresponding author.
Tel.: +8673 18975100970; E-mail address: yuanqingcsu@163.com Keywords: Probe; Frequency; Phase; Oscilloscope Abstract: A testing circuit of probe is designed to research the electrical properties of the probe under different loading frequencies.
Probe electrical properties will change due to continuous compression and extension of the probe in the test.
We believe that electrical properties of the probe will vary with loading frequency.
Based on experimental data, we can conclude probe electrical properties varies with loading frequency in probe testing.

There are many factors that affect the fretting performance of contact pairs, including metal material, fretting frequency (velocity), amplitude, normal force, use environment and so on.
Total 200,000 resistance is collected for a contact pair during fretting, they were processed to characterize fretting contact properties.
Among the three affecting factors, normal force is the most important one. 4μmSn-Au and 0.76μmAu-Sn behave bad fretting contact performance at 50gf normal force.
The fretting performance and influencing factors of printed circuit board (PCB) contacts.
Summary of fretting contact properties of common connector coatings.

Weld quality characteristics like micro structure, hardness and tensile properties are investigated and it is found that the usage of pulsed current leads to better weld quality characteristics when compared to continuous current mode. 1 Introduction AISI 304 L is a austenitic stainless steel with excellent strength and good ductility at high temperature.
By contrast, in constant current welding, the heat required to melt the base material is supplied only during the peak current pulses allowing the heat to dissipate into the base material leading to narrower Heat Affected Zone (HAZ).
Fig.5 Variation of hardness along the welded joint 1 2 3 4 5 6 7 8 9 7 8 9 Heat Affected Zone Fusion Zone Fig.6 Location of hardness along the weld joint The hardness values obtained using pulsed current mode are higher than contineous current mode.
The hardness and tensile properties of pulsed current mode welding are better than continuous current mode.
[6] G.Padmanaban, V.Balasubramanian, Influences of pulsed current parameters on Mechanical and metallurgical properties of gas tungsten arc welded AZ31B Magnesium alloy, Metals & Materials International, 17 (2011) 679-687

Siddhartha Inst. of Technology, Vijayawada-520 007, India 3 Mechanical Engg Department, J.
Plan of Experiment Surface roughness of machined fiber reinforced composites depends on many factors like machining parameters (cutting speed, feed rate etc), cutting tool properties, work piece properties, machine tool vibrations etc.
Here, for this experimental purpose the predominant factors which affect the surface finish (cutting speed, and feed rate) were considered.
Remaining all other controllable factors was kept constant.
Assessment of some factors influencing tool wear on the machining of glass fibre-reinforced plastics by coated cemented carbide tools.

The purpose of carrying out two-dimensional numerical simulation includes: ①{TTP}9312 deformation of the initial and secondary support caused by the extraction in different depth. ②{TTP}9313 distribution and value of stress of the initial and secondary support caused by the extraction in different depth. ③{TTP}9314 analyze the security of tunnel structure in operation and clarify whether to allow further mining below the tunnel. ④{TTP}9315 put out the treatment play on the basis of mechanical properties.
The displacement and stress of the marble rock and silicalite rock sections far away from the coal seam is almost not affected by the extraction.
Only those sections (carbonaceous shale rock and siliceous shale rock) near the coal seam are obviously affected by the extraction.
If the radial construction joints of the structure are reinforced through adding steel bar, the scope of the area affected by the gob will be enlarged, and the uneven settlement decrease.
Considering the various factors, scheme of intermittent reinforcement at radial construction joints, small-scale and high intensity reinforcement is designed for Wusongshan Tunnel, with a 50cm raise of the roof of tunnel.

Previous research found that SMD is affected by physical properties such as viscosity, surface tension and injection pressure [13-16].
The parameters that affect spray cone angle are atomizer design (dimension of the discharge orifice), liquid properties (viscosity and surface tension) and injection pressure [10, 17-20].
Three properties of palm olein blends that affect the characteristics of the spray were measured: kinematic viscosity, density and surface tension.
Table 2 shows the result of physical properties measurement.
Rollbuhler, Factors Influencing the Effective Spray Cone Angle of Pressure-Swirl Atomizers.

This is somewhat difficult, since actually the material property values of a specific structure are not exact as those nominal values, they are influenced by several factors, such as manufacture process, temperature and others, inducing uncertainties to wave velocity.
In this study, a genetic algorithm (GA)-based approach is proposed for damage localization using measured ToF of the scattered Lamb wave without knowing the material properties and the theoretical wave velocity a priori.
Due to the dispersive nature of Lamb wave, the waveform of the scattered wave is always distorted, affecting the accuracy of measurement of ToF in time domain.
It is expected that when the minimization of J is achieved, the best estimation of the location of the damage and the wave velocity is obtained, thus the properties of the structure are not needed beforehand.
With the wave velocity of the scattered Lamb wave as a parameter to be identified, the material properties are not needed a priori.