bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Device for the Measurement of Functional Finger Pinch Movement Discrimination
Authors: Han Jia , Waddington Gordon , Anson Judith , Adams Roger
Published: July 2011

Proprioception provides feedback that is vitally important for motor control. A deficiency in joint proprioception is thought to be associated with various upper limb rheumatological disorders. Currently, there is a lack of a portable device that could be used for measuring functional proprioception at the fingertips in the field. Therefore, a novel portable device for measuring pinch movement discrimination between index finger and thumb of either hand was constructed. This device is manually operated and requires the subject to make an absolute judgment of a joint position, choosing which one of five pre-experienced positions is being presented to them, with trials given in a random order. The 5 physical differences used were between 1.22 and 2.42cms. Reliability analysis was performed over a 7-day interval, with 8 healthy young adult volunteers. The discrimination scores, measured as the Area Under the Curve (AUC), for the group showed a mean (SD) of 0.794 (0.544) and 0.794 (0.549) on days 1 and 8, respectively. The day 1 and 8 reliability assessed with the interclass correlation coefficient ICC(3,1) was 0.85. Nondominant hands showed better pinch discrimination on the two days, with AUC values of 0.800 and 0.810 compared with 0.788 and 0.778, but these differences were not statistically significant (p>0.05). No difference in pinch movement discrimination was found between sexes. The ease of use and portability of the novel device for measuring functional proprioception at the fingertips described in this note make it ideal for measuring hand functional proprioception as part of clinical and epidemiological studies. The mid-range AUC discrimination scores found with healthy young adults mean that factors thought to diminish (eg. hand injury) or improve (eg. having expert finger skills) discrimination could be detected with the device.
A Parameter Selection Method for Support Vector Interval Regression Model
Authors: Chen Yong Qi
Published: July 2011

The support vector interval regression model is an effective method to estimate imprecise data. Parameters of this model is very important in order to obtain the excellent regression result. The flexible polyhedron search algorithm is a fast optimization algorithm. Based on the flexible polyhedron search algorithm, this paper proposes an automatic parameters selection method for the support vector interval regression model. Experiments illustrate the validity and applicability of the support vector interval regression model based on the flexible polyhedron search algorithm.
Research on the Low-Carbon Benefit Evaluation System of the Logistics Enterprise Based on the FAHP Method
Authors: Zhou Ye , Ye Zhi Song , Wang Yun Zhu
Published: July 2011

The low-carbon economy becomes a hot issue in every country after Copenhagen’s meeting, and Logistics enterprise is an important economic entity to achieve a low carbon economy, so how to effectively evaluate the effect of logistics enterprises and low-carbon benefits of emission reduction become a problem that really needed to solve. Therefore, it evaluated the effects of low-carbon benefits of logistics respectively from the economic benefits, logistics operational efficiency and CO2 emission reduction by AHP. Based on it, logistics enterprise evaluation model of low-carbon benefits was built in the way of fuzzy comprehensive evaluation, and finally verified the effectiveness of the evaluation system with a case.
A Non-Cooperative Game Framework for Concurrent Tolerance Design
Authors: Lu Cong
Published: July 2011

This paper proposes a non-cooperative game framework for concurrent tolerance design. The optimization issues in concurrent tolerance design for manufacture and assembly are discussed, and the mechanism of non-cooperative game for concurrent tolerance design is investigated. Finally, the algorithm is proposed to achieve concurrent tolerance design with non-cooperative game.
The Study of Heat-Engines Based on Refrigerant Phase-Change Circulation
Authors: Jiang Wei Jiang
Published: July 2011

This paper firstly introduces the principles of Stirling heat engines based on refrigerant phase-change circulation. This heat engines use two external heat reservoire. When the refrigerant in an engine cylinder absorbs heat from high-temperature heat sources, refrigerant is transformed from liquid to gas and the volume of the refrigerant expands to drive the piston apply work. When the refrigerant releases heat to low-temperature sources, the volume of the refrigerant shrinks. Therefore, phase change thermal engine technology using solar energy, industrial waste heat and heat produced by combustion of any fuel to work, no gas emissions, high thermal efficiency and environmental advantages. Thermal phase transition and thus the engine technology will be in the field of energy and power of a cutting-edge technology, great development potential and prospects.
The Effects of Nozzle and Workpiece Placements on Cooling Rate in the Vacuum High-Pressure Gas Quenching Furnace Based on CFD
Authors: Wang Zhi Jian , Wang Xiao Yan , Shang Xiao Feng
Published: July 2011

Studying how and how much the factors affect on the cooling rate of workpieces is very significant to improve the ability of vacuum high pressure gas quenching furnace. From changing the structure and technology of nozzle-type vacuum high pressure gas quenching furnace, by a large number of computer simulation, this paper discusses some factors affecting the cooling rate. By changing the number and distance of nozzles on each wind pipe, we can better control the cooling rate and uniformity of workpieces. From the perspective of improved process, the number, shape, size and placement of the workpieces have certain effects on cooling rate, in which the placement of the workpiece is very significant and significant. The simulation results for the further development of new high-pressure gas quenching vacuum device provide a theoretical basis.
Rotating Tube Method for Preparing Cu-Ca Alloy Semi-Solid Slurry
Authors: Wang Ming , Yang Xiang Jie , Guo Hong Min
Published: July 2011

Rotating tube method for preparing Cu-Ca alloy semi-solid slurry was investigated. Compared the microstructure of slurry prepared through the tube and of untreated original sample, discussed evolution characteristics of microstructure flowing through the rotation tube, and analyzed effect of process parameter on microstructure. The results show that the semi-solid slurry of Cu-Ca alloy could be prepared through rotating tube process; the melt were hardly affected in the initial stage. The tube began to play a major part in the next stage and the melt were stirred effectively in the last stage; Spherical microstructures of Cu-Ca alloy slurry were obtained through controlling or adjusting the process parameters to control solidification conditions.
Research about the Porous Ceramics of Al2O3-TiB2 System by SHS Method
Authors: He Bo Lin , Yu Ying Xia , Li Qiu Ping , Liu Jing
Published: July 2011

Porous ceramics composite was prepared with mixed powders (Al, TiO2 and B2O3) by SHS (Self-propagating High-temperature Synthesis) method. The effects of the particle size of aluminum power, the additives of SiC and the compacting pressure on the product properties and the pore size, as well as the combustion process in the Al2O3-TiB2 system were researched. The effects of all factors on properties of the product were tested in this paper. The microstructure and mechanical properties (density and compressive resistance strength) were reported. It is learnt from the study that the relation between the open porosity and the pore size does not exist, the former depends on the green density, and the latter depends on the particle size of the aluminum powder. The porous ceramic composite with porosity is ranged from 45% to 68%, pore size is ranged from 1um to 400um, and the compressive strength is about 9.5 MPa. SEM observations of fracture surface suggest that the fracture mode is brittle fracture, and the microstructures of the porous of ceramic composite is very homogenous.
A Novel Determination Method of IPMC Young’s Modulus Based on Cantilever Resonance Theory
Authors: Hao Li Na , Gao Jian Chao , L. Hont Tao
Published: July 2011

The research is aimed at presenting a novel determination method of IPMC (Ionic Polymer Metal Composites) Young’s Modulus. This method would fill up some deficiencies, such as damaging the tested IPMC strip, having low precision and so on, in the traditional method like tensile test and bending test. The paper presents a novel determination method based on cantilever resonance theory. Cantilever resonance theory is one of the methods to determinate the Young’s modulus of metal wire and metal strip. This method adopts Euler-Bernoulli beam to build a vibration differential equation of the beam. Then, by using the separate variable method, the general solution of the equation would be obtained. Considering the boundary conditions, a formula about the relation of the Young’s modulus and the first natural frequency is obtained. Limited by the experimental equipment and test method, this method has not been applied in the composite material. This paper attempts to apply this method in the IPMC material. The laser probing DISP (displacement) technique is applied in the test experiment. The laser displacement transducer is a kind of accurate un-contact laser displacement measurement set. The distance measured, which could be used to measure the change in position of the tested object, is based on the triangle principle.
Fatigue Analysis of Titanium Welded Joints Using Mesh-Insensitive Structural Stress Approach
Authors: Fu Li Bin , Yang Xin Hua , Dong Ping Sha , Ren Rui Ming
Published: July 2011

Mesh-insensitive structural stress approach is a robust method for fatigue characteristic analysis of welded structures and has been validated in correlating a large amount of published fatigue test of steel welded joints in the literature. Regarding Titanium welded joints, the combination of stress states and geometric shape can also lead to stress concentration that can result in fatigue crack initiation around the welded joints. This paper aims to analyze well-documented fatigue data of transverse and longitudinal fillet welded joints of Titanium using mesh-insensitive structural stress approach. This study is the first time using the approach for titanium fatigue data analysis. The results show that the employed method can correlate fatigue data of Titanium welded joints noticeably and make sense to understand the effect of thickness on fatigue life of the joints better than conventional methods.
Study on Swelling Solution for High Tg Epoxy Resin Substrate
Authors: Han Guo Fang , Shi Jian Hua , Chen Zhi Dong
Published: July 2011

A new type of swelling solution is developed, which is applied for the pre-treatment of plating-through-hole (PTH) of print circuit board (PCB) made up of high Tg epoxy resin substrates. The results show that the best formula is 144 organic esters 200g/L and hexylene glycol 2g/L. The treatment temperature and processing time is 60°C and 6min, respectively. Under the optimal conditions, the residue caused by drilling can be removed completely through the process including swelling, oxidation and neutralization.
Effect of Gas Nitriding on CO2 Corrosion Behavior of 40Cr Steel
Authors: Wang Bing Ying , Sun Zhen Tong , Zhou S.N.
Published: July 2011

In this paper, 40Cr steel was gas-nitrided for varying time. The microstructure and microhardness of the nitrided layer were examined by means of optical microscope and microhardness tester. The CO2 corrosion behavior of 40Cr steel influenced by nitriding was studied using high temperature high pressure autoclave. The SEM, EDS and XRD technique were adopted to study the characteristics of CO2 corrosion scales on 40Cr steel. The results show that the pitting is generated for all the un-nitrided and nitrided specimens, however, the corrosion tendency and corrosion rate decreases with nitriding time increasing, mainly due to the compact of FeCO3 formed on the surface.
Non-Invasive Test of Soft Tissue for Tissue Reaction in Needle Biopsy
Authors: Liu M. , Zhang Q.H. , Gao L.Y. , Qin Xue Mei
Published: July 2011

Needle biopsy is a widely used medical procedure in which a tissue sample is cut and removed by needle for examination to identify and diagnose cancer and other diseases. Predictions of soft tissue deformation and reaction caused by needle insertion are important for the accuracy of this procedure. In this paper, in order to aquire the properties of soft tissue, indentation experiments of porcine livers are performed as non-invasive test to measure the force response depending on time in various indentation depth and indentation velocities conditions. A nonlinear least square method on Matlab have been created to fit the indentation results. According to the experimental and fitting indentation force-time curves, the coefficients of Neo-Hookean model and Kelvin model which are selected to develop the nonlinear model of porcine liver are acquired . Finally, a finite element model of liver based on experimental data is finally developed and succeeds in simulating the stress relaxation character and force-time curve. This finite element model and methodology can be used to investigate soft tissue reaction in needle biopsy.
Finite Element Analysis of Bending Resistance for RC Beams Strengthened with AFRP Sheets
Authors: Zeng Qing Dun , Zhou Yong Lu
Published: July 2011

In order to reveal the failure properties of AFRP sheet-reinforced beams under 4-point bending, a 3-D finite element model of RC beam, including rebar, interface and sheet elements, was established by using MIDAS FEA finite element software. The stress and displacement of each of components in beam were solved by cycling calculations. In terms of Code for Design of Concrete Structures, the initial cracking loads of RC beams strengthened with prestressed and non-prestressed AFRP were further obtained, which are relatively conformed to the existing experiment. The results show that, compared with the beams strengthened with prestressed and non-prestressed AFRP, the initial cracking load of the former has considerable increase.
Experimental Studies and Technology Process on Phosphor-Gypsum Decomposition for Producing Sulfuric Acid and Lime
Authors: Ying Guo Liang , Zhou Ming Kai , Li Bei Xing
Published: July 2011

Using phosphor-gypsum (PG) to produce sulfuric acid is one of the most effective ways of recycling sulfur resources. This paper studied the melting and decomposition behavior of PG with High Temperature Microscope and Infrared Sulfur Analyzer. Moreover, a new process of PG decomposition for producing sulfuric acid and lime is proposed and discussed. The result shows that the minimum communion point of PG is higher than 1200 °C, the desulphurization degree of PG at 1200 °C under reducing-oxidizing atmosphere can exceed 90%, and the decomposition products of PG have high hydration activity. This means that little liquid phase will occur if PG is decomposed at1200°C, so PG can be decomposed using a fluidizing furnace. The new process of PG decomposition for producing sulfuric acid and lime has many advantages over the traditional process of PG decomposition for producing sulfuric acid and cement, and has a broad application prospects.
Air Combat Situation Assessment by Gray Fuzzy Bayesian Network
Authors: Xuan Yong Bo , Huang Chang Qiang , Li Wang Xi
Published: July 2011

Automatic and accurate situation assessment is essential for aircraft to conduct and maintain operations autonomously and effectively. There are many uncertainties during the process of air combat situation assessment which have a significant influence on operational decision making. For the uncertainty of advanced aircraft in air combat Situation assessment, with the uncertainty knowledge representation of gray fuzzy theory and uncertainty reasoning of Bayesian network, the fuzzy information can change into the probability of domain knowledge through fuzzy probability conversion formula, A gray fuzzy Bayesian network model for situation assessment of air combat is established, the simulation results shows that the model is reasonable and feasible.
Interfacial Stress Analysis of Fiber Sheet/Steel Plate-Reinforced Concrete Beams with Cracks under Tension and Bending
Authors: Ling Ling , Zeng Qing Dun , Wang Gui Yuan
Published: July 2011

On the basis of the analytical methods of composite mechanics, a layered shear-lag model was established to study the shear stress distributions of the interfaces between concrete and adhesive layer as well as adhesive layer and fiber sheet or steel plate for fiber sheet/steel plate-reinforced concrete beams with cracks under tension and bending. The results show that the properties of strengthened materials have some effects on the interfacial shear stress. The level of interfacial shear stress increases as both the length of cracks and thickness of fiber sheet or plate are increasing. The influence of crack spacing distance and thickness of adhesive layer on normalized interfacial shear stress is relatively less. The axial tensile force has some impacts on the interfacial shear stresses.
Sensitivity of the Carbon Fiber Interface in Epoxy
Authors: Zheng Hua Sheng , Zhu Si Rong , Li Zhuo Qiu , Li Jing
Published: July 2011

In order to improve the gauge factor of polymer-matrix carbon fiber reinforced composites (CFRP) for strain sensing, the carbon fiber sensitive interface was constructed in epoxy by effectively overlapping the CFRP laminates in local area. The strain sensitivities of the carbon fiber interface were proved by the cyclic tension test on the base specimens covered by the carbon fiber composites with the sensitive interface, and their much bigger gauge factors were revealed by the comparison with the polymer-matrix continuous carbon fiber composite. The sensitivity of the carbon fiber interface is originated from the change of the interfacial points due to the interfacial stress.
Investigation of the Process Capability of Water Cavitation Peening and Shot Peening Processing
Authors: Han Bing , Deng Chao , Ju Dong Ying
Published: July 2011

Water cavitation peening (WCP) with aeration is a recent potential method in the surface enhancement techniques. In this method, a ventilation nozzle is adopted to improve the process capability of WCP by increasing the impact pressure, which is induced by the bubble collapse on the surface of components in the similar way as conventional shot peening(SP). In this paper, the process capability of water cavitation peening and shot peening is investigated, The residual stresses in the near-surface and surface morphologies of spring steel SAE 1070 was characterized by X-ray diffraction (XRD), optical microscopy (OM). After peening treatment, changes in surface morphologies, as well as residual stress with the different peening duration were recorded. The obtained results indicate that the WCP processing had a better surface finish than SP processing.
Chip Formation and Cutting Performance Investigation on Titanium Alloy Machining
Authors: Lin Shen Yung , Cheng Y.Y. , Chung C.T.
Published: July 2011

First, a 2D orthogonal cutting model for titanium alloy is constructed by finite element method in this study. The cutting tool is incrementally advanced forward from an incipient stage of tool-workpiece engagement to a steady state of chip formation. Cockroft and Latham fracture criterion [1] is adopted as a chip separation criterion. By changing the settings of cutting variables such as cutting speed, depth of cut and tool rake angle to investigate the chip formation process and the variation of cutting performance during titanium cutting simulation. The changes of chip type, cutting force, effective stress/strain and cutting temperature with different cutting condition combinations are thus analyzed. The result demonstrates that the serrated chip type is obviously produced when cutting titanium alloy. Next, water-based and oil-based cutting fluids are employed in conjunction with proper cutting parameter arrangements to perform up-milling experiments. By measuring the cutting force, surface roughness and tool wear to investigate the effect of these combinations of milling variables on the variation of cutting performance for Ti-6Al-4V. The chip shape and cutting force obtained from the experiment are compared with those calculated from simulation. It is shown that there is a good agreement between simulation and experimental results.
Investigation on the Surface Finish, MRR and the Surface Damage during the EDM of Tungsten Carbide
Authors: Khan Ahsan Ali , Abdulkareem Suleiman , Abdul Ghani Nadiatul Amirah Ahmad , Mohammad Ariffin Dayanna Sarrah
Published: July 2011

EDM is a nontraditional method of removing material by a series of rapidly recurring electric discharges between an electrode (the cutting tool) and the workpiece, in a medium of a dielectric fluid. EDM is a precision machining technique and is used in making dies and molds of extremely hard materials that cannot be machined by conventional techniques. The present work was conducted in order to investigate the surface finish, material removal rate and the surface damage during EDM. Copper and carbide were taken as the electrode and the work materials for the present study. The influence of current and pulse-on time on the responses were studied. Design of Experiment (DOE) was used to conduct the investigation. It was found that MRR and surface roughness increases with both current and pulse on time. Tool wear, work surface damage and materials migration between the electrode and the workpiece was found to be increased with current.
Size Effect on Micro Tensile Test of Copper
Authors: Huang You Min , Chang Yao Min
Published: July 2011

There has been a significant research interest in metal micro-forming for the last ten years. However, neither a methodology nor an exact micro mechanical property has been well determined. Hence, several experiments are carried out in this research to point out the influence of “size effect”. Based on the comparison between the experimental data and relevant parameters, the material characteristics in micro scale can be found. In order to find the mechanical properties in micro scale, this study shows the effect of specimen size and grain size on the micro tensile test of copper material. Firstly, five copper micro-sheets with different thicknesses have been chosen as experimental materials. Since the minimum standard test piece formulated in ASTM is still too big for this micro tensile test, this study decided to shrink the sample size of specimen shape to 1/2 . Then the flow stress decreases with decreasing specimen size. This way is able to get the important factor which influence the flow stress on the micro tensile test. Secondly, these samples of different grain sizes are made by heat treatment. Then these samples of different grain sizes are used to conduct the experiment. According to the experimental result, the change of flow stress, which is influenced by various grain sizes, can be found. Finally, the change in the mechanical behavior between specimen size and grain size is obtained.
The Condition Monitoring of the Micro V-Grooving with a Single Crystal Diamond Tool Using the AE Technology
Authors: Jang Su Hoon , Kwon Hae Woong , Kang Ik Soo , Kim Jeong Suk , Kang Myung Chang
Published: July 2011

This study deals with the micro v-grooving of a single crystal diamond tool that is implemented on a 3-axis micro-stage. A method for monitoring the machining conditions is investigated using acoustic emission (AE) signals and cutting force signals in the micro-grooving. The AE signals and machined surface profiles are obtained under various machining conditions. The signals are acquired from an AE sensor that is attached to the tool holder and are investigated to identify the correlation with the machined surface profiles. It is found that the AE signal is an effective parameter for monitoring the texture of the machined surface.
Investigation of the Machinability of Inconel 718 in Room Temperature and Preheated Conditions
Authors: Nurul Amin A.K.M. , Fakhruzi Majed A. , Daud M.K. , Patwari Anayet Ullah , Ishtiyaq M.H.
Published: July 2011

Inconel 718 is widely used in the aviation, space, navigation and shipping industries because of its outstanding properties. The very mechanical characteristics that give this alloy the highly valued properties also make it one of the most difficult-to-machine aerospace materials. Due to the hardness of nickel-based super-alloys, such as Inconel 718, advanced tools like ceramics have been recommended to machine them. But ceramics are low conductive materials, and the heat generated during the machining of Inconel 718 transfers very slowly through them. The accumulation of generated heat on the cutting edges of ceramic tools causes many problems and sometime leads to premature tool failure. Hence in this study the effectiveness of PVD TiAlN coated carbide insert has been investigated. One approach to overcome the difficulties in machining of Inconel 718 is to use an external heat source to soften the work material surface layer to be removed in order to decrease its tensile strength. A new approach of preheating using inducting heating as an economical alternative to Laser Assisted Machining for end milling of Inconel 718 is presented in this paper. The machinability of Inconel 718 under varying conditions is evaluated by examining tool wear, surface roughness and chip morphology. With increasing work-piece preheating temperature, from room temperature to 420 °C, the advantages of Induction heating is demonstrated by an extended tool life and better surface finish due to more stable chip formation and elimination of micro and macro failure of the tool.
The Effect of Tool Edge Geometry on Tool Performance and Surface Integrity in Turning Ti-6Al-4V Alloys
Authors: Burhanuddin Yanuar , Che Haron Che Hassan , Ghani Jaharah A.
Published: July 2011

This paper focuses on the influence of cutting tool edge geometry, cutting speed and feed rate on the tool performance and workpiece’s surface integrity in dry turning of Ti-6Al-4V alloy using PCBN inserts. The parameters evaluated are tool life, wear rate, wear mechanisms, surface roughness and subsurface microstructure alterations. The rate of wear growth of the insert was assessed by progressive flank wear using optical microscope by taking photographs after certain length of cut. The wear mechanism at the end of tool life was investigated in detail using scanning electron microscope (SEM) and EDAX analysis. The results show, by increasing the cutting speed and feed rate resulted in tool life reduction. Cutting with honed edge insert at cutting speed of 180 m/min has shown very little wear, even after 20 min of cutting. The honed insert proved less sensitive to increases in feed rate than the chamfered insert. In general the honed insert showed a significant improvement in tool life. All inserts failed due to attrition wear and adhesion. No flank notch wear was observed, but some crater wear occurred at the chamfer land. Microstructure alteration was not found when machining using the different edge geometry. In these trials, the subsurface micro structural deformations in the direction of cutting were deformed grain boundaries and elongation of grains. Chip smearing and debris on the surface was also found.
Influence of Feed Rate on Surface Integrity of Titanium Alloy in High Speed Milling
Authors: Daymi A. , Boujelbene M. , Bayraktar E. , Ben Amara A. , Katundi D.
Published: July 2011

Titanium alloys have been widely used in industries, especially aerospace, energy and medical industries, due to their good mechanical and chemical properties. However, titanium alloys are typically difficult-to-cut materials. Milling induced surface integrity, including anisotropic surface roughness, residual stress, surface microstructure alterations and microhardness, has received little attention. This work investigated the effect of machining conditions, especially the federate, on surface integrity of workpiece of Ti-6Al-4V alloy machined using high speed ball end milling process. The experimental tests were performed at various cutting parameters and carried out in dry conditions on a vertical five-axis CNC milling machine, using a coated carbide tool. Surface finish was studied based on 3D topographic maps and microhardness depth profiles beneath the machined surface. Microstructure of the sub-machined surface was observed using an optical microscope in order to investigate the metallurgical deformation. X-ray diffraction analysis is performed to obtain the residual stress distribution beneath the surface.
Innovative Tools and Tool Steels for the Blanking of Press-Hardened Ultra High-Strength Manganese-Boron Steels
Authors: Hirsch M. , Krönauer B. , Golle Roland , Hoffmann Hartmut , Golle Matthias , Jesner Gerhard
Published: July 2011

One substantial goal of modern vehicle construction is to reduce weight at a high level of crash safety. When steel is used in lightweight construction, the process of press hardening of boron-alloyed steels can be of great importance. The heat treatment during hot forming process increases the material’s tensile strength to a level of approximately 1500 MPa. The increased tensile strength needs to be considered in subsequent manufacturing processes, such as punching operations. At present, laser cutting is a common method to cut press hardened sheet metal, a process which is more cost-intensive and time-consuming as conventional tools and tool steels cannot be produced with a profitable output. One aim of the present project has been the investigation of tool steels as well as the different damage mechanisms occurring during the blanking of press-hardened sheet metal. A new tool concept has therefore been realized, which comprises the entire expertise of the Institute. Thus, the tool developed is a very good basis for assessing tool steels and their damage behaviour. Tool life and damage mechanisms have been analyzed.
Hydrophobic Templates with Rough Patterns Fabricated by Laser Micromachining for Liquid Droplets Generation
Authors: Tseng Shih Feng , Huang Kuo Cheng , Chiang Don Yau , Chen Ming Fei , Hsiao Sheng Yi , Lin Yung Sheng , Chou Chang Pin
Published: July 2011

This paper presents an approach to utilize high precision pulsed Nd:YAG laser to fabricate a rough array-pattern on a soda-lime glass plate by a laser-induced backside writing (LIBW) process, and a laser-induced plasma assisted ablation (LIPAA) technique. The current study investigates the effect of process parameters such as single-shot laser exposure time and number of passes on the material removal rate. After depositing 695 nm thick Teflon thin film on the glass plate, the surface of the laser micro-machined template becomes hydrophobic. The surface roughness, annular groove profile and surface micrograph were measured by an atomic force microscope, a profilometer, and a scanning electron microscope, respectively. A uniform liquid droplet by the sessile drop method is generated on the hydrophobic template. Droplet characteristics, such as contacted angle, size, and shape, are measured with a surface tension analyzer and microscope. This work also discusses the relationship between the formed droplets and the process recipe of the micro-machined template. The proposed approach can apply to future for uniform lens array formation.
Multi-Sphere Mirror Design of YAG Laser Applied for Glass Substrate Cutting
Authors: Wu Wen Hong , Huang Kuo Cheng , Tseng Shih Feng
Published: July 2011

A thermal fracture process applied to the brittle materials has become a foremost technology, and applied to cut the LCD glass substrate. One advantage of this process is that the cross-section of cut glass substrate will be smooth with low residual stress after thermal fracture processing. The multi-sphere mirror aims to repeatedly reflect the light energy within upper and lower mirror in order to enhance the laser beam absorption rate of glass under cutting. Moreover, with a proper design of multi-sphere mirror, the energy distribution of applied laser can provide an ideal thermal fracture condition to improve cutting speed of glass substrate. A novel reflective mirror with multi-sphere surface was developed and reported to transform the regular laser energy distribution toward the ideal one. Furthermore, the shape of multi-sphere mirror is optimized by Taguchi method so as to meet the surface requirement that can get the ideal energy distribution. This paper presents a series of simulation results and analysis results of multi-sphere mirror calculated by the TracePro opto-mechanical software.
Surface Roughness and Wear Behavior of Laser Machined AISI H13 Tool Steel
Authors: Kasman Şefika , Saklakoğlu İ.E.
Published: July 2011

The effects of laser machining process parameters namely, scan speed and frequency on wear performance of AISI H13 hot work tool steel were investigated in this study. The process parameters are combined with wear process factors and the responses of wear tests were evaluated. The results showed that both friction coefficient and wear rate are affected by process parameters. The average friction coefficient and wear rate increased with an increase in frequency at each set of scan speed. Lowest scan speed and highest frequency produced higher surface roughness and rough texture form.
Laser Surface Melting of Austenitic Cr-Ni Stainless Steel
Authors: Stavrev Dimitar , Dikova Tsanka D. , Shtarbakov Vladimir , Milkov Mario
Published: July 2011

The present paper deals with the microstructure and hardness distribution in width and in depth of the surface layer of steel Ch18N10T GOST (AISI 321, EN X6CrNiTi 18-10) after surface melting by continuous wave CO2 laser. Light microscopy, XRD analysis and Vickers hardness testing (HV5 and HV0,05) have been used in our research. Phase analysis shows disturbance of the mono-phase initial austenitic structure in the treated layer. The structure of the melted pool consists of austenite with dendrite morphology and δ-ferrite situated in the dendrites’ cores. The ferrite has been clearly identified by XRD analysis. As a result from fast heating and cooling, ferrite, obtained by diffusionless sliding mechanism, was observed along the austenite grains’ boundaries in the heat affected zone. The presence of small inclusions of supposed Ti carbide, non-identified by XRD analysis, was also observed. The durometric investigations show that the surface hardness in the melted zone is in the range 180-210 HV5 while that of the basic metal is about 270 HV5.
Measuring the Changes in InP Morphological and Electrical Specifications Caused by Oxygen Ion Implantation
Authors: Ramezani A.H. , Hantezadeh M.R. , Ghoranneviss M. , Sari A.H.
Published: July 2011

This paper is the results of oxygen ion implantation on morphological and electrical properties of indium phosphate (InP) semiconductor wafers. The oxygen ions were implanted at 30 keV and various doses in the range between 5×10 15 to 5×10 17 ions/cm2 and at nearly room temperature. The changes in surface roughness and resistivity before and after the implantation is studied using atomic force microscopy (AFM) and four-point probes technique, respectively. The results show that the resistivity is depend on the ion implantation dose. In addition, the RMS roughness of implanted samples dramatically increases by accumulation of oxygen ion dose.
Morphology and Mass Changes with Magnetic Field during the Electrodeposition of Ni-Co
Authors: Ebadi Mehdi , Basirun Wan Jeffrey , Alias Yatimah
Published: July 2011

The influence of a static magnetic field of 4.4 T on the electrodeposition process on copper plates immersed in a solution of Nickel and Cobalt ions is presented. The electrodeposited layers characterized by Scanning Electron Microscopy (SEM) including Energy Dispersive X-Ray (EDX), X-Ray Diffraction (XRD) and Atomic Force Microscopy (AFM).It was observed that the difference between the mass of electrodeposition with the application of a Permanent Parallel Magnetic Field to the electrode surface (PPMF) and the electrodeposited layers without the PPMF, increased with the increase of current density. The presence of the PPMF gave smoother electrodeposited surface compared to without the PPMF. The increase in current density gave fewer the cracks on the electrodeposited surface.
Influence of Hot Extrusion Process on the Mechanical Behavior of AA6061/SIC Composites
Authors: Pakdel Amir , Farhangi Hassan , Emamy M.
Published: July 2011

The effect of hot extrusion process on the microstructure, mechanical properties and fracture behavior of metal-matrix composites (MMCs) of AA6061 alloy reinforced with 10 volume percent particulate SiC with the average size of 46 µm was studied. The MMC ingots were fabricated by the stir casting method and were extruded at 450°C at a ram speed of 1mm/s and at the extrusion ratios of 6:1, 12:1 and 18:1. Various techniques including metallography, density measurement, tensile testing, and SEM fractography were utilized to characterize the mechanical behavior of the MMCs. Results demonstrated that extruded composites possessed considerably lower porosity contents, higher strength, and enhanced ductility in comparison with the as-cast samples. In addition, further improvement in the mechanical properties of the extruded composites was noticed by increasing the extrusion ratio. Fractographic observations revealed that the brittle fracture behavior of the as-cast specimens was promoted by cracking of the large SiC particle clusters. Whereas, the fracture surfaces of extruded composites showed extensive tear ridge formation by initiation and growth of shallow dimples, around the cracked particles, which is characteristic of a ductile fracture process. This change in the fracture behavior and improvement in mechanical properties is attributed to the break up of particle clusters and diminishment of pores during the extrusion process.
Prediction Laser Sealed Advanced Ceramic Coatings Dimensions by Using Finite Element Model and Computational Method
Authors: Adel K.M. , Ekhlas E.K. , Shaker S.H.
Published: July 2011

A three dimensional FE modeling of the laser surface modification is presented. The design capabilities of the ANSYS (11) software were employed for this purpose. The model calculates the dimensions of melting zone and heat affected zone. Model simulations are compared with experimental results that showed very good agreement. A one dimensional model in V.B language was presented too. The model based on conduction of heat in one dimension neglecting the other losses of heat. The results of VISUAL BASIC were compared with experimental results which showed a very good agreement. The two methods were compared with each other to showing which method have a good prediction compared with experimental results in calculating of fusion zone and heat affected zone "HAZ".
Characterization and Response Evaluation of Detonation-Gun Sprayed Alumina-Titania Ceramic Composite
Authors: Raja Kumar Sundaram , Vijayaraghavan L. , Mayuram M.M.
Published: July 2011

Erosion due to solid particles impact has a detrimental effect on the performance of components used in various applications. Hard facing is widely used to combat wear in such situations. D-gun coating is increasingly popular for such applications. Alumina-titania composite has been deposited on mild steel substrate. The coating has been characterized and their tribological responses have been evaluated. Resistance to erosion, evaluated through standard dry erosion test is highlighted in this work. An orthogonal full–factorial experimental matrix which includes all possible variables that contribute to brittle erosion was designed, conducted and validated. The variation of erosion rate with process parameters was mathematically modeled by using the regression analysis method.
Method, Technology and Equipment for in Depth Surface Hardening
Authors: Stavrev Dimitar , Dikova Tsanka D.
Published: July 2011

The present work deals with a new method, technology and equipment developed for “in depth surface hardening” of large rotary details and tools, made of constructional, carbon, alloyed or low-alloyed tool steels. According to the technical requirements the details and tools have to possess hardened layer with specific shape, depth in the range 20-35mm and surface hardness of 35-62 HRC. The “in-depth hardening” was performed by quenching and self-tempering. Preliminary volume heating and depth regulated local surface adjustable gas-flame heating were used. The gasflame heating was realized by gas-flame burners (CH4+O2) located near the details’ periphery, depending on the shape and depth of the hardened layer. The burners’ power and heating time were adjustable. The cooling was performed by showers located near the details’ periphery also depending on the shape of the hardened layer. Water or polymer water solution was used as cooling media and its capacity was adjusted in the beginning. Due to the heat accumulated during the preliminary heating and the heating up to the quenching temperature of the surface layer, after stopping the cooling, subsequent self-tempering was applied. All of the equipment for realizing the whole hardening cycle, temperature and time control and parameters of heating and cooling was developed. Series of different details were hardened: traversing wheels and gears, forming rolls, rolling disks etc., made of construction and tool steels. The hardened layers obtained were with specific shape, surface hardness in the range of 35-60HRC and depth of the hardened layer of 15- 25mm.
Surface Modification of Polystyrene Beads by UV/Ozone Treatment
Authors: Yusilawati A.N. , Maizirwan M. , Sopyan Iis , Hamzah M.S. , Ng K.H. , Wong Chiow San
Published: July 2011

It is known that polystyrene must be chemically modified to make its surface amenable to covalent cross-linking with protein. The aim of this study was to set up a UV/Ozone system and investigate the effects of UV/Ozone treatment on polystyrene surface. Microsize polystyrene beads with an average size of 150 μm in diameter were treated with and without distilled water at the same treatment time, ozone flow-rate and UV intensity. The treated beads were analyzed by ATR-FTIR, SEM, EDX and hydrophilicity measurement. The results show that the hydrophilicity of the surface of polystyrene beads was increased after the UV/ozone treatment and the introduction of carbonyl, carboxyl and hydroxyl groups on the polystyrene beads surface was also confirmed. It was demonstrated that the UV/Ozone system was effective for treatment of polystyrene bead and the best result was obtained without distilled water.
Optimization of Multipass Turning Parameters by Genetic Algorithm
Authors: Ahmad Nafis , Tanaka Tomohisa , Saito Yoshio
Published: July 2011

Optimization of cutting parameters is one of the key obstacles for CAD/CAM integration. In this work optimum cutting parameters, the best sequence, number, and type of passes of turning operation are determined by Genetic Algorithm (GA). Proposed optimization strategy ensures that no constraint will be violated at the optimum condition and determines the optimum number and type of passes such as rough, finish and semi-finish passes to complete a multipass turning operation. Here objective function is the unit production cost and constraints are limits of cutting force, power, tool life, stability condition, tool chip interface temperature, surface finish, feed rate to depth of cut ratio and the available rotational speed of spindle of machine tool.
Building a Simulation Model for Prediction of Temperature Distribution in Laser Sealing Processing of Advanced Ceramic Coatings
Authors: Adel K.M. , Ekhlas E.K. , Mariyam J.G.
Published: July 2011

This paper describes the development of computer model used to characterize the heat transfer properties of the laser sealed advanced zirconia based ceramic coating. The model is built using ANSYS (11) software where all the environments simulated to be similar to the experimental environments. According to experiments dealed with the same data the temperature cant be reading since it is difficult to be fast enough as the changes occurs due to small interaction time .The temperature profile was recorded with each traverse velocity, the temperature changes with time and velocity were recorded too.
Some Aspects of Deposition Parameters of RF Sputtered Ferromagnetic Film Germane to the Study of Magnetoresistive Sensing Devices
Authors: Akhtar Pervez , Javid Ali Tariq , Aziz Arshad
Published: July 2011

The paper describes results of investigation on sputtered NiFe Films to determine the sputter deposition condition that could produce magnetic field sensors with the desired magnetic and magnetoresistive properties. The magnetic thin films materials used in such devices should have a low coercive force, a low anisotropy field and low magnetization dispersion, α50 with high magnetoresistance ratio. From the results presented, it is shown that that the most useful films for 82%Ni-Fe composition are produced at 200 °C-250 °C moderate substrate temperatures. It is also possible to specify the substrate bias potential and sputter gas pressure sputter deposition conditions under which the 82%Ni-Fe thin films may be employed for the production of magnetoresistine sensors with near optimum magnetic and magnetoresistive properties. The work also provide understanding of the effects on the magnetic properties of sputtered magnetic films that is very limited as current literature is almost entirely limited to evaporated magnetic films.
Thread Forming of a Micro Screw for Storage Devices Using Finite Element Analysis
Authors: Lee H.W. , Song Jung Han , Lee Geun An , Lee Hye Jin , Park K.D.
Published: July 2011

High precision micro screws have been widely required for the fastening parts of electronic storage devices. Teeth’s forming of the micro screw is generally utilized by a cold thread rolling process with a flat die. This process for micro sized parts has some difficulties such as the design of die shape, alignment between dies, and process managements. In this paper, it is focused on the effect of the alignment between dies and material, and process parameters in simulation. The investigated parameters are the friction coefficient and the relative position between stationary and moving dies using a numerical simulation. The simulations provide that the shear friction factor of 0.9 is proper for preventing slip between dies and raw material and the relative position of two dies has to be set to the half length of the pitch for maintaining the continuous thread profiles. The deformed shapes of the pitch part and the top part of threads can be demonstrated the feature of experimental result. The folding phenomenon appeared at the top part of threads, which seemed to be induced by a lack of the metal flow under micro sized deformation.
Relation between Surface Roughness and Overlap Interval in Fused Deposition Modeling
Authors: Ahn Dae Keon , Kweon Jin Hwe , Choi Jin Ho , Lee Seok Hee
Published: July 2011

Rapid prototyping (RP) can efficiently fabricate high level models with complex shapes. Hence the RP has been widely applied in various industrial fields. However, as the technology is inherently performed by layered manufacturing process, the surface quality of the RP part is not satisfactory to use general industrial purpose. This is the reason that surface roughness problem has been key issue in RP. In this paper, relation between surface roughness and overlap interval is investigated based on a surface roughness formulation in fused deposition modeling (FDM). Additionally, effects of surface angle and filament shape are analyzed and discussed to predict surface roughness distribution by the overlap interval variation.