bluuebunny/crossref_metadata_2025 huggingface dataset:
Tool Wear Performance of CVD-Insert during Machining of Ti-6%Al-4%V ELI at High Cutting Speed
Authors: Ibrahim Gusri Akhyar , Che Haron Che Hassan , Ghani Jaharah Abd.
Published: June 2010

Machining of titanium alloys as aerospace material that has extremely strength to weight ratio and resistant to corrosion at high-elevated temperature, become more interested topic. However, titanium alloys have low thermal conductivity, relative low modulus elasticity and high chemical reactivity with many cutting tool materials. The turning parameters evaluated are cutting speed (55, 75, 95 m/min), feed rate (0.15, 0.25, 0.35 mm/rev), depth of cut (0.10, 0.15, 0.20 mm) and tool grade of CVD carbide tool. The results that pattern of tool life progression is rapidly increase at the initial stage. It was due to small contact area between the cutting tool and the workpiece. At the first step of machining, the chip welded at the cutting edge but some chip removed away from the cutting edge. Wear mechanism produced are abrasive wear, adhesive, flaking, chipping at the cutting edge and coating delamination.
Intelligent Monitoring and Estimation of Surface Roughness on CNC Turning
Authors: Tangjitsitcharoen Somkiat
Published: June 2010

In order to realize an intelligent machine tool, an in-process monitoring system is developed to estimate the in-process surface roughness. The objective of this research is to propose a method to estimate the surface roughness during the in-process cutting by utilizing the in-process monitoring of cutting forces. The proposed in-process surface roughness model is developed based on the experimentally obtained results by employing the exponential function with five factors of the cutting speed, the feed rate, the tool nose radius, the depth of cut, and the cutting force ratio. The multiple regression analysis is utilized to calculate the regression coefficients with the use of the least square method. The prediction interval of the in-process surface roughness model has been also presented to monitor and control the in-process estimated surface roughness at 95% confident level. It is proved by the cutting tests that the proposed and developed in-process surface roughness model can be effectively used to monitor and estimate the in-process surface roughness by utilizing the cutting force ratio with the highly acceptable prediction accuracy achieved.
Monitoring of Cutting Conditions with Dry Cutting on CNC Turning Machine
Authors: Tangjitsitcharoen Somkiat , Ratanakuakangwan Suthas
Published: June 2010

This paper presents the additional work of the previous research in order to verify the previously obtained cutting condition by using the different cutting tool geometries. The effects of the cutting conditions with the dry cutting are monitored to obtain the proper cutting condition for the plain carbon steel with the coated carbide tool based on the consideration of the surface roughness and the tool life. The dynamometer is employed and installed on the turret of CNC turning machine to measure the in-process cutting forces. The in-process cutting forces are used to analyze the cutting temperature, the tool wear and the surface roughness. The experimentally obtained results show that the surface roughness and the tool wear can be well explained by the in-process cutting forces. Referring to the criteria, the experimentally obtained proper cutting condition is the same with the previous research except the rake angle and the tool nose radius.
Study on NC Compliant Bonnet Tool Abrasive Polishing Based on Magnetorheological Torque Servo
Authors: Shi Yong Jie , Zheng Di , Zhan Jian Ming , Wang Long Shan , Liu Xiao Feng , Wang Gang Ming
Published: June 2010

In this paper, a NC compliant abrasive polishing system was developed based on a magnetorheological torque servo (MRT), using a bonnet as the polishing tool. The MRT was uesd to provide a load acting on bonnet tool to produce the polishing force. In order to find the factors affecting the polishing quality, the models of the applied load, polishing force and contact pressure between the bonnet and the part were established based on Hertz theory, and the factors affecting the contact pressure were analyzed. Theoretical analysis indicated that there was a significant effect of the applied load, the initial pressure of the bonnet and the radius of curvature of the part on contact pressure. Experiments were carried out to verify the validity of the models, and experiment results showed that the roughness of the part was improved greatly and the polishing efficiency could be controlled by changing the initial pressure of the bonnet and applied load.
Chipping Brittle Materials: A Finite Element Analysis
Authors: Mostafavi Seyed Saleh , Zhang Liang Chi , Lunn Jason
Published: June 2010

Edge chipping by an indenter has been used to investigate the fragmentation of brittle materials. This paper proposed a constitutive model for studying both the initiation and propagation of cracks during the chipping of concrete. The analysis was carried out by the finite element method using a commercially available code, LS-DYNA. The results showed that a zone with very high compressive stresses appears beneath the indenter and causes the material to break or crush. Most of the external work, about 78%, was dissipated in the crushing zone while only a small percentage (less than 17%) contributed to form chips/fragments. As the indentation proceeded, radian-median cracks initiated and propagated downward and parallel to the front surface of the material to form a half penny crack. The crack tips from both sides of the indenter on the surface would then deviate toward the free edge, leading to a chipping scallop at a critical load.
In Situ Observation and Anisotropy of Free Surface Roughening for Polycrystalline Metals
Authors: Furushima Tsuyoshi , Masuda Tetsuro , Manabe Kenichi
Published: June 2010

To understand the free surface roughening phenomena of polycrystalline metals, the surface roughening behaviors of three kinds of metal sheets were investigated under uniaxial tension. The materials used were AZ31 magnesium alloy, SPFC 590Y steel, and A5052-O aluminum alloy. In the in-situ observation of surface roughening for AZ31 magnesium alloy, it seemed that the surface of each grain roughened independently and the roughness increases with increasing plastic strain. In contrast to A5052-O and SPFC, the anisotropy of free surface roughening was observed for AZ31 magnesium alloy. Compared with planar anisotropy , the microscopic anisotropy of surface roughening is not related to . In AZ31 magnesium alloy, the anisotropy of surface roughening arises and, instead of the r-value, another parameter is needed to evaluate the anisotropy of free surface roughening.
Edge Chipping of Rock: An Experimental Study
Authors: Yao Qing Yu , Zhang Liang Chi , Bao Rong Hao , Lunn Jason , Melmeth Craig
Published: June 2010

This paper investigates experimentally the edge chipping of a rock to assess the cutting performance of a conical and a pyramidal tip. It was found that the conical tip generates many radiated cracks and results in a larger amount of fine rock grains due to crashing. The size of chips produced by the pyramidal tip is bigger. It was concluded that the critical chipping energy has approximately a linear relation with h9/4 of which h is the depth of cut of the tip.
Microstructure and Properties of TiAlN/AlN Composite Film Deposited on Cam’s Profile by Ion Beam Sputtering Technique
Authors: Guo Pei Quan , Wang Shou Ren , Cui Huan Yong
Published: June 2010

The study reports a new surface formation technology during manufacturing process of parallel indexing cam mechanism, ion beam sputtering deposition, in which the operation temperature can be controlled below the limitation of phases exchanging or at room temperature. Phase exchanging deformation can be avoided and the shape accuracy and dimension accuracy can be improved compared with surface quenching process. The microstructure and properties of TiAlN/AlN composite film deposited on the profile surface of cam (made of 45 steel) by ion beam sputtering deposition were discussed. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM) analysis has been used to characterize film’s microstructure and properties. The micro-hardness and adherence grade were tested.
Fretting Fatigue Resistance of Fe- Ni-Cr-Al Coating Prepared by Thermal Spraying Subjected to Rotational Bending
Authors: Liu Wei , Xu Xiang Yang , Zhao Hui Mei , Sun Chuan Jing
Published: June 2010

The fretting fatigue experiments of the coated and the uncoated axle specimens were carried out on a test rig simulating assembly loading condition of actual axles and wheels in 1/4 size ratio. The microstructure and Vickers hardness of the coating were examined before and after fretting tests. The results showed that, the thermally sprayed coating, which consisted of lamellar α-(Fe, Cr) and γ-(Fe, Ni) dual-phase microstructure protected the surfaces of specimens from fretting damage. The fretted surface of the coating was covered with an oxide film of Fe and Cr that stopped surface adhesion. The strong work hardening of the coating under the fretted surface could prevent fretting cracks from vertically propagating and hinder nucleation of fatigue cracks in the specimen substrate. As a result, the fatigue strength of the coated specimen was increased more than 50%.
Development of Nano Crystalline Nickel Coating for Engineering Applications
Authors: Ravi Srivathsan , Ganesh Karthick Venkatesh , Ramanathan Arunachalam , Annamalai Jegan , Jaiswal Prasanna Kumar
Published: June 2010

The current research focuses on developing nano-crystalline nickel coating for engineering applications through pulse plating technique. Based on the literature survey, the current density, duty cycle and frequency were identified as important grain refining parameters. Coating was done over a mild steel sample after mechanical polishing, vapour degreasing and anodizing. Experiments were conducted using the three determining parameters and their influence on the properties of the coating was evaluated. Coatings were then characterized for the surface morphology and hardness. The XRD analysis for the surface morphology resulted in the grain size of 19 nm and the hardness measured from the microhardness tester was 677 HV which is higher than the hardness reported in the available literatures. The influence of the pulse plating parameters on the grain size and hardness of the coating has been listed out for the benefit of the scientific community.
Coating of Polythiophene by Microwave Plasma Polymerization Process
Authors: Paosawatyanyong Boonchoat , Kamphiranon Phensupa , Bhanthumnavin Worawan
Published: June 2010

This research is focused on improving electrical conductivity of conjugated polythiophene films fabricated by microwave plasma assisted polymerization process. Polythiophene thin films with 300 nm to 1.5 micron thickness were deposited on glass substrates in a highly uniform fashion as evident by Scanning Electron Microscopic analysis. An efficient incorporation of the iodine dopant into the films was also successfully performed to give thin films with 120-250 nm thickness. The films were characterized by various spectroscopic methods. Attenuated total reflectance-Fourier transform infrared spectroscopy showed absorption frequencies of important functional groups mostly characteristics of thiophene. The doped fabricated films exhibited UV-vis spectra indicative of increased -conjugation (439-535 nm). Results from energy-dispersive X-ray spectroscopy confirmed the presence of iodine in the films of upto 10%. Electrical conductive measurements revealed that the undoped films has the conductivity in the range of 1.4×10-5 to 1.0×10-4 S/cm.
Nitrogen and Bias Effect on Homoepitaxial Diamond Growth by Hot-Filament Chemical Vapor Deposition
Authors: Tsai Hung Yin , Chang Chih Cheng , Wu Chih Wei
Published: June 2010

The development of homoepitaxial films for advanced device applications has been studied, but high growth rate and diamond film quality have not yet been explored. In the current study, high quality homoepitaxial diamond films were grown on type Ib (100) HPHT synthetic diamond substrate by hot-filament chemical vapor deposition. The reactant gases were mixed by CH4 and H2 with small amounts of N2 (500 to 3000 ppm). Besides, a bias system was used to assist diamond film deposition. The pyramidal crystals on diamond surface can be suppressed and high quality diamond film of FWHM (Full Width at Half Maximum) = 10.76 cm-1 with high growth rate of 8.78 ± 0.2 μm/ hr was obtained at the condition of adding 1000 ppm nitrogen. At the bias voltage of -150 V, the pyramidal crystals can also be suppressed and high quality diamond film of FWHM = 10.19 cm-1 was obtained. With nitrogen addition above 2000 ppm, diamond film was partly doped and some sp2 structures appeared. These homoepitaxial diamond films were characterized by optical microscopy and micro-Raman spectroscopy.
Surface Roughness and Stress Responses of a Feldspar Porcelain to Fatigue Impact
Authors: Lymer Richard , Yin Ling , Peng Zhong Xiao , Jones Robert H.B. , Sandham Andrew
Published: June 2010

Dental ceramics are attractive in restorative dentistry due to their approximations to the appearances and functions of human teeth with which we chew our food. Chewing processes generally occur at cyclic loading range of 70–800 N and up to 1400 cycles per day. Most fatigue studies on dental ceramics were conducted at the loads up to 250 N. These loads are much smaller than the maximum bite forces of 500–700 N and tooth clench or grinding forces of up to 800 N. This paper reports on an investigation of fatigue response of a dental porcelain at the higher end of the load range impacted by a tungsten carbide ball. The responses of surface roughness and contact stress to the applied loads and cyclic numbers were quantitatively studied. The results show that the cyclic numbers had significant influences on both average surface roughness Ra and maximum roughness Rmax (ANOVA, p<0.05). However, the applied loads did not significantly affect Ra and Rmax values (ANOVA, p>0.05). It is also found that the contact stress significantly reduced with the cycles (ANOVA, p<0.05) but did not show a significant change with the applied loads (ANOVA, p>0.05).
A Vacuum Sucking Approach to Preventing Chips from Attaching to Machined Surface in Cutting of KDP Crystals
Authors: Zheng Zi Wen , Chen Hao Feng , Dai Yi Fan , Gao Hang , Wang Gui Lin , Li Xiao Ping
Published: June 2010

Potassium Dihydrogen Phosphate (KDP) crystals are used for the key components in high power density solid-state laser for Inertial Confinement Fusion. KDP crystals are mainly machined in the dry cutting condition to avoid ‘Fogging’ of the crystals. The main difficulty identified in dry machining of KDP is chip removal from the machined surface. A vacuum sucking device based on venturi vacuum pump is used to suck the chips during cutting, and the relationship between level of vacuum in cutting zone and the comply air pressure was established. An empirical model for chip emission during turning processes is used to analyze the influence of cutting parameters on the chip emission. The influence of cutting parameters on the removal of chips is investigated. Finally, a face turning of KDP crystals is carried out with the turning parameters of feed rate 1um/rev, depth of cut of 0.8 um/rev and the cutting speed from 1.82m/s to 3.9m/s. A super-smooth surface with chips free in the whole sample is achieved, having the surface roughness of 2.994nm (Ra) measured by AFM. The surface quality achieved satisfies the requirements of KDP crystals implemented in high power lasers.
Machining Properties of Insulating ZrO2 Ceramics Using Porous Copper Electrodes
Authors: Fukuzawa Yasushi , Yukihiro Keiji , Yamasita Ken
Published: June 2010

Insulating ceramics were considered as machinable material with the electrical discharge machining method using the assisting electrode method, which was proposed and advanced by the authors. The mechanical properties changed with the experimental parameters, including the physical characteristics of the workpiece and the tool electrode. In this research, sintered ZrO2-Y2O3 insulating ceramics were subjected to EDM. To investigate the effects of the porous tool electrode material on the removal rate, the porous copper cylinder material was fabricated by PECS (pulse electric current sintering) method. The relative density changed from 60 to 95 wt%. The suitable machining characteristics could be obtained with a relative density of 85% at the positive electrode polarity. The shape of electrodes was transcribed on the workpiece surface more precisely than the solid copper electrode.
Isothermal Rolling of Mg-Based Laminated Composites Made by Explosion Cladding
Authors: Zhang Xin Ping , Tan Ming Jen , Yang Ting Hui , Wang Jing Tao
Published: June 2010

Rolling of Al-Mg-Al tri-layer composite material fabricated by the explosion cladding method was simulated using finite element methods. The rolling temperature was determined based on the flow stresses of AZ31 magnesium alloy and 7075 Al alloy at elevated temperature. The strain distribution in the plates during rolling and effects of the reduction ratio on the separation in the Al/Mg/Al laminate were studied. The simulation agrees with experimental results.
Machining of Micro-Channels on Brittle Glass Using an Abrasive Slurry Jet
Authors: Pang King Lun , Nguyen Thai , Fan Jing Ming , Wang Jun
Published: June 2010

This paper presents a study of using an abrasive slurry jet for the machining of micro channels on brittle glasses. The machined surface morphology and channel dimensions are used to assess the technology. Surface morphology was found featuring with two types of wave patterns; one was along the channels with large wave lengths as a result of the jet deflection during the motion of nozzle, and the other was due to viscous flow that resulted in smooth surface eroded predominantly by ductile mode. The investigation showed that using higher jet pressure and higher particle concentration enables to create channels with higher depth, although these widened the channels and degraded the surface quality in some cases by inducing a larger number of pit fragments on the surface. With proper control of the operating parameters, this technology can be used for machining micro channels on brittle materials with high quality of surface finish.
A Study of Abrasive Jet Micro-Grooving of Quartz Crystals
Authors: Moridi Alireza , Wang Jun , Ali Yasser M. , Mathew Philip , Li Xiao Ping
Published: June 2010

Owing to its various distinct advantages over the other machining technologies, abrasive jet machining has become a promising machining technology for brittle and hard-to-machine materials. An experimental study is presented on the micro-grooving of quartz crystals using an abrasive airjet. The effect of the various process parameters on the major machining performance measures are analysed to provide a deep understanding of this micro-machining process. Predictive models are then developed for quantitatively estimating the machining performance. The models are finally verified by an experiment. It shows that the model predictions are in good agreement with the experimental results under the corresponding conditions.
Design of a Fast Tool Servo Based Diamond Turning Machine for Fabricating Micro-Structured Surfaces
Authors: Yu De Ping , Gan Sze Wei , Wong Yoke San , Rahman Mustafizur , Hong Geok Soon
Published: June 2010

Increasing demand for ultraprecision components with micro-structured surfaces has attracted focus on diamond turning research. In this paper, a fast tool servo (FTS) based diamond turning machine is presented for fabricating micro-structured surfaces with high accuracy. A design criterion is established to serve as a guide in choosing or designing a suitable type of FTS for a micro-structured surface. Experiments on fabricating sampled micro-structured surfaces are carried out to demonstrate the effectiveness of the designed FTS based diamond turning machine.
Migration of Materials during Finishing Micro-EDM of Tungsten Carbide
Authors: Jahan Muhammad Pervej , Rahman Mustafizur , Wong Yoke San
Published: June 2010

Present study aims to investigate the migration of materials onto the surface of workpiece and electrode during fine-finish die-sinking and milling micro-EDM of tungsten carbide using pure tungsten electrode. The effect of materials transfer on the machined surface characteristics is also presented. The machined surfaces have been examined under scanning electron microscope (SEM) and energy dispersive X-ray (EDX) in order to investigate the changes in chemical composition due to the migration of materials. It has been observed that materials from both workpiece and electrode transfer to each other depending on machining conditions and discharge energy. A significant amount of carbon migrates to both electrode and workpiece surface due to the decomposition of dielectric hydrocarbon during breakdown. The migration occurs more frequently at lower gap voltages during finish die-sinking micro-EDM due to low spark gap and stationary tool electrode. Milling micro-EDM suffers from lower amount of carbon migration and fewer surface defects which improve the overall surface finish and reduce surface roughness significantly.
Thermal Effect Analysis of Femtosecond Laser Scribing of Silicon
Authors: Wan Da Ping , Mathew Philip , Wang Jun
Published: June 2010

Ultra-short pulsed laser ablation of crystalline silicon is characterized by a complicated heat diffusion process. In this research, a computational investigation is undertaken to achieve the temperature distribution and heat effect as a function of micromachining parameters. Heat accumulation and heat affected zone (HAZ) of silicon ablation by ultra-short lasers are estimated through solving coupled energy balance equations. The laser energy deposition and possible non-thermal ablation process are analyzed in the case of succession of laser pulses. Thermal-mechanical response induced by temperature gradient is discussed around the laser ablation region. The agreement between the model calculations and experimental results show that this research provides an efficient thermal analysis method, and a feasible way to optimize process parameters with minimum thermal damages.
Parameter Optimization of Injection Molding Ti-6Al-4V Powder and Palm Stearin Binder System for Highest Green Density Using Taguchi Method
Authors: Nor Nor Hafiez Mohamad , Muhamad Norhamidi , Ahmad Sufizar , Ibrahim Mohd Halim Irwan , Harun Mohd Ruzi , Jamaludin Khairur Rijal
Published: June 2010

In this paper, the titanium alloy powder of Ti-6Al-4V is mixed with binder 60wt% of palm stearin and 40wt% of polyethylene for metal injection molding (MIM) process. Injection molding parameters has been optimized using Taguchi method of L27 (313) orthogonal array. Highest green density has been identified as the green part quality characteristic or as an output for this study. Parameters optimized are the injection pressure, injection temperature, powder loading, mold temperature, holding pressure and injection speed. Besides those, interaction of the injection pressure, injection temperature and powder loading were studied. The analysis of variance (ANOVA) is employed to determine the significant levels (α) and contributions of the variables to the green density. Results show that the injection pressure has highest significant percentage followed by injection temperature, powder loading and holding pressure.
A Comparison of Dry and Underwater Laser Micromachining of Silicon Substrates
Authors: Tangwarodomnukun Viboon , Wang Jun , Mathew Philip
Published: June 2010

Laser micromachining has been widely used for decades to fabricate the micro- and submicro-component structures. However, thermal and physical damages are crucial issues associated with the process. Underwater laser ablation has been developed as a damage-free micro-ablation technique. In this paper, a comparison of the conventional dry and underwater laser micromachining of silicon is presented. It shows that the heat affected zone (HAZ) can be reduced significantly in the underwater laser process, though the material removal rate is reduced due to the energy loss by the water layer. The effects of pulse frequency, traverse speed and laser energy on the obtained kerf width, HAZ and cut surface quality are also analyzed and discussed.
Laser Dieless Drawing Process for Metal Micro-Tubes
Authors: Furushima Tsuyoshi , Noda Yuta , Manabe Kenichi
Published: June 2010

A drawing process using tools such as dies, plugs and mandrels has been conventionally applied as a means of miniaturizing tubes. However, it is not easy to scale down the conventional process to micro sizes for many reasons related to the tools used in the process. It is difficult to fabricate micro tools with high accuracy, and to insert a plug or a mandrel into a fine tube. Thus, the development of new drawing technologies for the fabrication of micro-tubes without the need for tools such as dies, plugs and mandrels is necessary. A laser dieless drawing technique with local heating using a laser as the heating source has been focused on for the fabrication of micro-tubes. In this study, a dieless drawing with a semiconductor laser setup is designed and developed. A tube of stainless steel, SUS304, with an outer diameter of 0.52mm and thickness of 0.1mm is used in the experiments. A laser dieless drawing experiment is carried out to investigate the effect of the laser power and drawing speed on the drawing limit. Finally, the effectiveness of laser dieless drawing process is discussed.
Parameter Optimization towards Highest Micro MIM Density by Using Taguchi Method
Authors: Ibrahim Mohd Halim Irwan , Muhamad Norhamidi , Sulong Abu Bakar , Jamaludin Khairur Rijal , Nor Nor Hafiez Mohamad , Ahmad Sufizar , Harun Mohd Ruzi , Zakaria Hafizawati
Published: June 2010

Nowadays, micro metal injection molding has become among the promising method in powder metallurgy research to produce small-scale intricate part at an effective process and competitive cost for mass production. This paper investigated the optimization of highest green strength which plays an important characteristic in determining the successful of micro MIM. In this paper, stainless steel SS 316L with D50 = 5.96µm was used with composite binder, which consists of PEG (Polyethelena Glycol), PMMA (Polymethyl Methacrilate) and SA (Stearic Acid). Feedstock with 61.5% with several injection parameters were optimized which highly significant through screening experiment such as injection pressure(A), injection temperature(B), mold temperature(C), injection time(D) and holding time(E). Besides that, interaction effects between injection pressure, injection temperature and mold temperature were also considered to optimize in the Taguchi’s orthogonal array. Analysis of variance (ANOVA) in terms of signal-to-noise ratio (S/N-larger is better) for green density was also presented in this paper. Result shows that interaction between injection temperature and mold temperature(BxC) give highest significant factor followed by interaction between injection pressure and mold temperature(AxC). Single factor that also contributes to significant optimization are mold temperature(C) and injection time(D). This study shows that Taguchi method would be among the best method to solve the problem with minimum number of trials.
Fabrication and Detection for the Skeletons of Micro Aerial Vehicle Using Precision Injection Molding
Authors: Lee Jeou Long , Ho Chao Hsien , Lin Yi , Shen Yung Kang
Published: June 2010

In this work, skeletons of micro aerial vehicle are fabricated by precision injection molding. The Taguchi method is adopted to identify the important factors that govern the shrinkage of MAV skeletons. The results indicate that the most significant factor in the shrinkage of a skeleton formed by precision injection molding is the mold temperature.
An Analytical Approach to the Extrusion Pressure of Bimetallic Tube
Authors: Xie Guo Liang , Liu Jing , Han Jing Tao , Yan Pei Jie
Published: June 2010

In this paper, the extrusion process of bimetallic tubes is discussed, and the extrusion pressure is calculated based on the method of energy conservation, according to the three categories of metal flow that may occur during the process. A number of parameters, geometry of bimetallic tube, mechanical properties of material components and friction conditions, are highlighted in this analytical method. Compared with the data of TP304l/20G bimetallic tubes which were extruded at 1100-1200 °C, the calculated results show a good agreement with the industrial results, with the error less than 10 %. It also proves that the friction between the two layers play an important role in the process.
Modeling of Strip Shape during Cold Rolling of Thin Strip
Authors: Jiang Zheng Yi , Du X.Z. , Du Yan Bing , Wei Dong Bin , Hay Matthew
Published: June 2010

Strip shape is an important factor affecting the strip quality significantly during cold rolling of thin strip. In the paper, finite element simulation models of the strip shape in cold rolling for both symmetrical and asymmetrical rolling cases were successfully developed. The strip edge drop and the effect of the rolling force on the strip shape (the thickness distribution along the strip width) have been obtained. The developed finite element model has been verified with the experimental value, which shows they are in good agreement. The obtained results are applicable to control the rolled thin strip shape during cold rolling practice.
A Numerical Investigation of Extrusion through Bezier Shaped Curved Die Profile
Authors: Rout Akshaya Kumar , Maity Kali Pada , Rath Sushant Kumar
Published: June 2010

The die profile plays an important role in reduction of extrusion load, evolution of uniform micro-structure and overall improvement of surface integrity of extruded product. In the present investigation, a numerical analysis has been carried out for extrusion through cosine die profile using DEFORM software for plane strain deformation using rigid plastic material. The extrusion load has been predicted. The effective stress, strain, strain rate and velocity distribution have been determined. It is proposed to investigate the evolution of uniform microstructure and the effect of strain hardening in the extrusion process in future work.
WPPM: Microstructural Analysis beyond the Rietveld Method
Authors: Scardi Paolo , Ortolani Matteo , Leoni Matteo
Published: June 2010

The basics of the Whole Powder Pattern Modeling and its implementation in the PM2K software are briefly reviewed. The main features and functionalities, and most common line broadening models are introduced with the aid of working examples related to the instrumental profile and to a plastically deformed metal. A summary of the main expressions is reported in the appendix, together with a list of useful references.
Domain Size Analysis in the Rietveld Method
Authors: David W.I.F. , Leoni Matteo , Scardi Paolo
Published: June 2010

The implementation of a physically-sound size broadening model for peak profiles in the Rietveld method is presented. TOPAS macros are provided and the results compared with analogous modelling performed according to advanced analysis methods such as the Whole Powder Pattern Modelling.
In Situ Diffraction Studies: Thermal Decomposition of a Natural Plumbojarosite and the Development of Rietveld-Based Data Analysis Techniques
Authors: Madsen Ian C. , Grey Ian E. , Mills Stuart J.
Published: June 2010

A study of the thermal decomposition sequence of a sample of natural arsenian plumbojarosite has been undertaken using in situ X-ray diffraction. The sample was heated to 900°C using an Anton-Paar heating stage fitted to an INEL CPS120 diffractometer. The data were analysed using a whole-pattern, Rietveld based approach for the extraction of quantitative phase abundances. The instrument configuration used required the development and application of algorithms to correct for aberrations in the (i) peak intensities due to differing path lengths of incident and diffracted beams in the sample and (ii) peak positions due to sample displacement. Details of the structural models used were refined at selected steps in the pattern and then fixed for subsequent analysis. The data sequence consists of some 110 individual data sets which were analysed sequentially with the output of each run forming the input for analysis of the next data set. The results of the analysis show a complex breakdown and recrystallisation sequence including the formation of a major amount of amorphous material after initial breakdown of the plumbojarosite.
Molecular Motion by Refinement of TLS Matrices from High Resolution Laboratory Powder Diffraction Data: Implementation in the Program TOPAS and Application to Crystalline Naphthalene
Authors: Halasz Ivan , Dinnebier Robert E.
Published: June 2010

Molecular motion by refinement of TLS matrices from high resolution laboratory powder diffraction data: implementation in the program TOPAS and application to crystalline naphthalene
Direct Access to the Order Parameter: Parameterized Symmetry Modes and Rigid Body Movements as a Function of Temperature
Authors: Müller Melanie , Dinnebier Robert E. , Ali Naveed Z. , Campbell Branton J. , Jansen Martin
Published: June 2010

The first order phase transition of CsFeO2 was investigated using synchrotron powder diffraction data as a function of temperature. Two alternative approaches were used to describe the deviation of the framework crystal structure relative to the high-symmetry parent structure: symmetry (a.k.a. distortion) modes and polyhedral-tilt parameters. In both cases, the relevant parameters were refined as a function of temperature using the method of parametric Rietveld refinement. We demonstrate a semi-automated and generally applicable method for the determination of spontaneous lattice strain variations, order parameters and power-law exponents as derived from Landau theory.
“Powder 3D Parametric”- A program for Automated Sequential and Parametric Rietveld Refinement Using Topas
Authors: Rajiv Paneerselvam , Dinnebier Robert E. , Jansen Martin
Published: June 2010

A new program to perform fast sequential and parametric whole powder profile refinement of in situ time-resolved powder diffraction data is presented. The program interacts with the launch mode kernel of the total powder pattern analysis software suite Topas® for doing the refinements. The program provides a graphical interface platform, upon which the huge Topas input command files necessary to perform sequential and parametric refinements can be easily prepared and executed. This program requires the user license dongle for Topas academic version 3 or higher.
Residual Stress Distribution in Austenitic Stainless Steel Pipe Butt-Welded Joint Measured by Neutron Diffraction Technique
Authors: Maekawa Akira , Oumaya Toru , Noda Michiyasu , Takahashi Shigeru , Saito Toru
Published: June 2010

This paper describes residual stress measurements and analysis of austenitic stainless steel pipe with a butt-welded joint. The measurements were done with neutron diffraction and strain gauge techniques. The measured results had typical characteristics of butt-welded pipe regarding both the decline of stress along the axial direction and the bending distribution of axial stress along the radial direction. The measured residual stress distribution by neutron diffraction was shifted more to the tensile side than that by the finite element method simulation. However, the measured radial and axial strains, except for the hoop strain determined by neutron diffraction, coincided well with analysis strains. The hoop strain was actually equivalent strain converted by a correction method because a different lattice plane had to be used to measure hoop strain. This might be one reason why the difference occurred. Therefore, future study of the correction method would be desirable.
Large Deformation and Mechanical Effects of Damage in Aged Duplex Stainless Steel
Authors: le Joncour Lea , Panicaud Benoit , Baczmanski Andrzej , François Manuel , Braham Chedly , Paradowska Anna Maria
Published: June 2010

The lattice strains in large tensile deformations, up to the fracture of the sample were measured using neutron TOF method. For the first time, the range of large deformation was studied measuring lattice strain in the deformation neck and using special correction for macrostress value. It was found that during large plastic deformation the lattice stresses arise almost linearly with the macrostress value. The relaxation of elastic strains in some groups of ferritic grains (corresponding to reflections 211 and 200) can be connected with initiation of damage process in the ferritic phase.
The Influence of Casting Geometry on the Tensile Properties and Residual Stresses in Aluminium Castings
Authors: Sadrossadat Mohsen , Johansson Sten
Published: June 2010

The soundness and the performance of castings are significantly affected by generation and accumulation of residual stresses. This has been proven that mechanical properties and residual stresses level of the casting components are affected by thermal gradient across the casting component during cooling and some intrinsic physical properties of the material. In the present work, microstructural development, mechanical properties, residual stress evolution and cooling curves associated with different legs of a mixed–section grid castings have been investigated employing scanning electron microscope, optical microscope, 3D measurement equipment, computerized thermal data acquisition instrument and tensile testing machine. Experimental results show that the accumulated residual stress in circular, triangular and rectangular grid shapes is increasing respectively. From the results it can be seen that there are clear influences of grid’s geometry on the microstructure and mechanical properties. The geometrical stiffness can affect a lot the residual stress level and the casting modulus has a big influence on the microstructure and mechanical properties.
The Robot Concept at STRESS-SPEC for the Characterisation or Semi-Finished Products
Authors: Brokmeier Heinz Günter , Randau Christian , Tekouo William , Hofmann Michael , Gan Wei Min , Müller Martin , Schreyer Andreas , Petry Winfried
Published: June 2010

The materials science diffractometer STRESS-SPEC located at Forschungsneutronen¬quelle Heinz Maier-Leibnitz (FRM-II) in Garching/Germany is a dedicated instrument for residual strain, texture and microstrain analysis. Comparably low gauge volumes of 1x1x1mm³ for gradient investigations in many types of materials can be investigated. A robot system consisting of a robot type Stäubli RX160, a laser tracker and a heavy vibration free basement was installed to overcome limitations in gradient investigations of residual stresses and crystallographic textures in semi-finished and finished products. The robot can carry up to 30kg with precise positioning. Al7020, an Al-alloy for airspace application, was used to perform a first global texture measurement using the robot.
Measurements of Residual Stress in a Welded Compact Tension Specimen Using the Neutron Diffraction and Slitting Techniques
Authors: Hosseinzadeh Foroogh , Bouchard P. John , James Jonathan A.
Published: June 2010

The residual stress field in a compact tension specimen blank extracted from a non-stress-relieved thick section butt weld has been measured using neutron diffraction and the slitting method. Significant triaxial residual stresses were found in the specimen that is normally assumed to be stress free. Moreover the level of stress was sufficient to make a significant contribution to the crack driving force in creep crack growth tests. The benefits of using more than one measurement technique in such investigations are demonstrated.
Internal Residual Strain of GlidCop for Materials of the High-Heat-Load Components
Authors: Sano Mutsumi , Takahashi Sunao , Watanabe Atsuo , Kitamura Hideo , Kiriyama Koji , Shobu Takahisa
Published: June 2010

We measured internal residual strain of GlidCopTM, a copper dispersion strengthened with aluminum oxide. The residual strains were measured by X-ray diffraction using synchrotron radiation. The purpose of this study is to verify the accuracy of an elastic-plastic analysis, which has been employed for the fatigue life prediction of GlidCop. As a result, the residual strain was estimated to be 0.11- 0.13% at any number of cycles, which is in good agreement with the analysis solutions. As to the plastic strain, we need to increase the accuracy of the calibration curve for the relationship between the FWHM of the diffraction profile and the plastic strain.
Determination of the Residual Stress Field around Scratches Using Synchrotron X-Rays and Nanoindentation
Authors: Khan M.K. , Fitzpatrick Michael E. , Edwards L.E. , Hainsworth S.V.
Published: June 2010

The residual strain field around the scratches of 125µm depth and 5µm root radius have been measured from the Synchrotron X-ray diffraction. Scratches were produced using different tools in fine-grained aluminium alloy AA 5091. Residual stresses up to +1700 micro-strains were measured at the scratch tip for one tool but remained up to only +1000 micro-strains for the other tool scratch.
The load-displacement curves obtained from nanoindentation were used to determine the residual stresses around the scratches. It was found that the load-displacement curves are sensitive to any local residual stress field present and behave according to the type of residual stresses. This combination of nanoindentation and synchrotron X-rays has been proved highly effective for the study of small-scale residual stresses around the features such as scratches.
Neutron Residual Stress Measurement of Railway Rails Using Image Plate
Authors: Sasaki Toshihiko , Yaguchi Osama , Suzuki Hiroshi
Published: June 2010

In this study, the authors investigated the application of the area detector for the purpose of evaluating residual stress in rails by means of diffraction technique. A rail used in the Hokuriku-Line of West Japan Railway Company (JR-West) was used as a specimen for this study. The rail was removed due to initiation of cracks caused by rolling contact fatigue. The present method refers to neutron stress measurement with a two-dimensional detector and corresponding data analysis.
Effect of Compressive Deformation on Carbide Precipitation in a Fe-C-Mo Alloy
Authors: Yu Hong Wei , Wu Kai Ming
Published: June 2010

Carbide precipitation in a Fe-C-Mo alloy was investigated by means of large compressive deformation and isothermal treatment utilizing Gleeble thermal simulator. The precipitated carbides were Fe3C, (Fe,Mo)2C, (Fe,Mo)3C and (Fe,Mo)6C. The dislocations and deformation bands formed by large compressive deformation promoted the carbide precipitation. It was found that the sequence of carbide precipitation was not changed by large compressive deformation.
In-Situ Observation for Elucidation of Stress Corrosion Cracking Mechanism in High-Temperature and High-Pressure Water
Authors: Fujishiro Tomoyuki , Shobu Takahisa , Kiriyama Koji , Yamamoto Atsushi
Published: June 2010

In-situ diffraction measurements were carried out on a tensile specimen of SUS304 stainless steel using a small autoclave at BL22XU at SPring-8. The temperature of circulating water in the autoclave was changed from room temperature to 561 K under ambient pressure and also under a pressure of 8.8 MPa. Tensile stress of 260 MPa was applied to the specimen at 561 K under 8.8 MPa, and a two dimensional strain distribution was obtained by calculation based on measured lattice spacings of the γ-Fe311 plane under various conditions. The interior region of the specimen showed higher strain compared with that on the surface region. After the tensile deformation in the autoclave, CT images of cross sections of the specimen were taken. Void-like images with about 50 μm in size were observed.
Residual Stresses of Cr-N Films Deposited by Arc Ion Plating Investigated Using Synchrotron Radiation
Authors: Matsue Tatsuya , Takao Hanabusa , Kusaka Kazuya , Sakata Osamu , Masayuki Nishida
Published: June 2010

The structures of Cr-N films deposited by arc ion plating on steel substrates were investigated using a synchrotron radiation system that emits ultraintense X-rays. The Cr-N films were found to be mainly composed of {110} oriented CrN crystals, but they also had a small component of randomly oriented Cr2N crystals. The CrN220 diffraction shifts to a high diffraction angle as the annealing temperature increases. In contrast, the peak position of the Cr2N211 diffraction hardly changes with an increase in the annealing temperature up to 873 K. The ratio of nitrogen and oxygen to chromium at the film surface and inside in the film was estimated by Auger electron spectroscopy. After annealing at 973 K, the surface layer was oxidized, but the composition inside the Cr-N films (N/Cr = 0.83) remained unchanged. The residual stress in a 1600-nm-thick as-deposited CrN layer was found to be -11.0 GPa. The residual stresses of Cr-N films relaxed to thermal stress levels on annealing. However, the residual stress in the Cr2N layer could not be evaluated.
Evaluation of Residual Stress in Shot-Peened Tool by Means of Synchrotron Radiation Using an Area Detector
Authors: Miyazawa Yohei , Yaguchi Osama , Sasaki Toshihiko
Published: June 2010

In this study, the authors investigated the application of the area detector type method for the purpose of evaluating residual stress in tools having a V-groove. The specimen used was a shot-peened forming rack. This alternative method uses a diffraction ring and single incidence X-ray to clarify precisely and effectively complex stresses and stresses in narrow parts of the tools such as the teeth on the surface of the rack. In addition, the authors evaluated stress gradients generated after shot peening using synchrotron radiation (SR).
Residual Strain Profiles in Alumina-Zirconia Ceramic Composites
Authors: Ruiz-Hervias Jesus , Steuwer Axel , Gurauskis Jonas , Buslaps Thomas , Baudín Carmen
Published: June 2010

Residual strain profiles were measured by synchrotron X-ray radiation in Al2O3/Y-stabilized ZrO2 (YSZ) ceramic laminates. Different stacking sequences were employed, including alternating layers containing 5 and 40 vol.% YSZ. Residual strains were found to be fairly constant within each layer; although they change at the interface between layers with different compositions. Different behaviour is observed for the strains along the in-plane and normal directions.
Grain Tracking at the High Energy Materials Science Beamline of the Petra III Synchrotron Radiation Source
Authors: King Andrew , Schell Norbert , Martins René V. , Beckmann Felix , Ruhnau Hans Ulrich , Kiehn Rüdiger , Marrow T. James , Ludwig Wolfgang , Schreyer Andreas
Published: June 2010

Grain tracking is a term used to describe experiments that investigate polycrystalline materials in terms of the crystallites or grains from which they are composed, non-destructively and in three dimensions. The new German high brilliance synchrotron radiation source, Petra III, will become available to users in 2010 [1]. The GKSS research centre will operate two beamlines, including the high energy materials science beamline (HEMS) [2]. HEMS will feature an instrument dedicated to grain tracking, able to support a range of experiments of this kind. This paper describes the design and specification of this instrument, and gives examples of the types of experiments that will be possible.