bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Measuring the Micro-Table Position and Pose Based on Binocular Vision
Authors: Yang S.G. , Li Hang , Xue Yu Jun , Zhu H.L. , Li Ji Shun
Published: December 2010

Position and pose measurement is an important issue in the field of robot navigation, operation and assembly as well as other fields such as photogrammetry, computer vision, computer graphics and other disciplines. The micro-table as a machine tool, one of the key components for improving the processing quality of the product plays a particularly role. However, in certain circumstances, we could not continuously and steady proceed relying on the naked eye when precisely and rapidly measure the small size, color matching and identification and so on, and the existing detection methods are difficult to balance the contradiction between the speed and accuracy. This paper puts forward a measurement method of detection 6-dof micro-table position and pose based on binocular vision. Using two CCD cameras measure 2D micro-table coordinates of the four corners of points from different angles, by coordinates transformation, we can calculate the 3D coordinates of the four corners of points; then we can solve the micro-table position and pose with the four corners of points.
Ultrasonic-Vibration Hard Cutting Force Analysis with the Finite Element Method
Authors: Tong Jing Lin , Yan Yan Yan , Zhao Bo
Published: December 2010

Ultrasonic-vibration hard cutting (UVHC) is a advanced technology, where high- frequency vibration is superimposed on the movement of the cutting tool. Compared to conventional turning (CT), this technique allows significant improvements in processing hard-to-cut materials, by producing a noticeable decrease in cutting forces and a superior surface finish. The paper presents a finite-element model of both CT and UVHC. Stresses produced in workpiece and cutting forces acting on the cutting tool in UVHC are studied, and the influence of cutting parameters, such as cutting speed and cutting depth on cutting force are investigated.
Problems and Countermeasure Research of Modern Coal Enterprises to Implement ERP
Authors: Jiang Wu Ji , Jin Zhi Gang
Published: December 2010

The coal enterprise ERP system is a management platform that built on the basis of information technology to provide management thinking for decision-making layer and operation methods for employees. Smooth implementation of ERP system can make it possible to distribute enterprise resources reasonably and fulfill the requirement of bringing maximum financial profits. In the paper, the problems that modern coal enterprises to implement ERP faced are analyzed, including, there exist misunderstanding and lack the knowledge of ERP to leadership, there lack of manpower and energy to enterprises after the implementation of ERP, and improper choice of partner and ERP software, etc. The article points out that leaders should seek unity of thinking, fully realize ERP is “top managerial project”, pay attention to the implementation, and dare to undertake the responsibilities. The enterprises must improve the qualities of the staff, especially the leader's qualities, carefully choose the software providers and the partners to ensure the smooth implementation of ERP systems.
CNC Machining Methods of Drum with Fold Line Grooves
Authors: Han Hong Biao , Shang Z.D. , Li Ji Shun
Published: December 2010

In this paper, processing characteristics and difficulties of drum with fold line grooves are analyzed. Three kinds of CNC machining methods, namely three-axis linkage, single-axis servo and two-axis servo, are introduced. With CNC machining methods of single-axis servo and two-axis servo, the spindle motor of machine tool needs not to transform. A CNC system is developed which acquires the absolute position on the circle of drum through the spindle encoder and spindle zero position switch. It allows simultaneous servo position and velocity control of Z-axis AC servo motor or both Z-axis and X-axis AC servo motors. With the changes of angular displacement of spindle, the system manages the interpolation motion of X-axis and Z axis, so drums with fold line grooves can be achieved by this way. Both of these methods have been applied to transformation of machine tool with simple, economical and reliable operation. This paper also proposes three methods to improve the processing efficiency of the drum: increasing a function of return to zero rapidly, processing with more tools at the same time, processing external steel sleeve with fold line grooves and then installing it on a smooth drum.
The Simulation on Pro/e of Blique Plane Double-Enveloping Worm Gear
Authors: Zhang Yue Min , Lu S. , Xie Gang
Published: December 2010

A reasonable coordinate system of planar double-enveloping worm is set up. The curve surface structure of worm gear were been analysis. The curve surfaces have been initiated by the program with MATLAB and numerical model has been drawn. The 3D solid model and motion simulation of planar double-enveloping worm gear have been emulated with the software of Pro / e.
Structural Topology Optimization of the Column of Form Grinding Machine
Authors: Yao S.G. , Li Hang
Published: December 2010

Based on Topology optimization method of continuum the structural dynamic model has been built by constraint condition of volume and objective function of column natural frequency. In order to improve precision the dynamic characteristics of non-design region have been considered in optimization process. The column of structural optimization design has been done by applying topology optimization. The quality has not only reduced, but also the dynamic characteristic of the column has been improved. Thus the design effect has been reached.
Research on Frictional Wear Property of the High Vanadium High Speed Steel in Conditions of Low Slip-Roll Ratio
Authors: Chen Hui Min , Xu L.J. , Wang H.G.
Published: December 2010

The frictional resistance and abrasion mechanism of high vanadium high speed steel were studied by the self-made friction wear testing machine under the conditions of 0.5% slip-roll ratio. Results show that the frictional resistance increases with the increase of carbon content. The retained austenite and the shapes of carbides will change when the carbon content alters, which make the frictional resistance of the material change, and the proper quantities of retained austenite makes the impact toughness the matrix better; The spherical VC can prevent the initiation and expansion of cracks forming and make the frictional resistance increase. The abrasion mechanism is fatigue flake under the condition of rolling and sliding.
Development of a Kind of Miniature Pressure and Vacuum Compressor for Built-In Robot Wrist
Authors: Han Jian Hai , Guo B.J. , Zhao S.S.
Published: December 2010

This paper deals with a new type of miniature air compressor which mainly consists of a stepper motor, a pneumatic swing cylinder, and four small high-speed ON/OFF solenoid valves. By switching the four ON/OFF solenoid valves properly, the miniature air compressor can produce both pressure and vacuum. The pressure and vacuum characteristics of the developed compressor are experimentally investigated. Furthermore, the performance of working as a air compressor or a vacuum pump freely are proven by experiment results.
Discussion on Electromagnetic Radiation Protection Standard of Light Industrial Equipments
Authors: Zhang Zi Qiang , Yu G.Y. , Chen Shao Bo , Zheng Zhi Dan , Li R.D. , Li Y.
Published: December 2010

The popular international and Chinese electromagnetic radiation protection standards are introduced, including the ICNIRP guidelines constituted by the International Commission on Non-Ionizing Radiation Protection, the EN62233 standards established by the European Committee for Electrotechnical Standardization and the GB 8702-88 regulations constituted by Ministry of Environmental Protection of the People’s Republic of China, etc. The situation of the light industrial equipments electromagnetic radiation has been tested and analyzed: the power of the induction heater is often up to thousands kilowatts, and there are many electrical control components and many dense circuitries in light industrial equipments. Their complicated electromagnetic fields release continuously electromagnetic waves and engender electromagnetic radiations to the surrounding environment. And, Chinese electromagnetic radiation protection standards lack limits for band less than 100 KHz (except 50Hz). It makes the electromagnetic radiation assessment of light industrial equipments lack sufficient basis.
The electromagnetic radiation protection standard of light industrial equipments was discussed and the limits for electromagnetic radiation protection of light industrial equipments are suggested.
Study on Open Standard Control System of Walking Assistant Robot for the Elderly
Authors: Wu Xue Zhi , Zhang Xiao Dong , Wang C.Z.
Published: December 2010

To solve the problems of the control system of the working assistant robot for elderly such as lower efficiency and weak complicity. A kind of open architecture, modularity, extensible embedded robot control system is developed. The main contents include: Studied on a rich hardware interface and drivers, function easy-to-modular extended robot development platform. The paper presented the platform features, design concepts and system solutions of the robot control system and gave details of building approaches of the platform. On this basis, the functional modules of the robot were designed and implemented with the modular design approach. Finally a specified working assistant robot was created by loading the completed modules into the control system platform and some experiments were carried out on the robot system. Experiments results show that the system platform can be a convenient and effective way to develop multi-functional working assistant robot for elderly.
Surface Wettability of Polypropylene Non-Woven Using Atmospheric Pressure N2 Dielectric Barrier Discharge Plasma
Authors: Zhang Yan , Zhao Bo , Tong Jing Lin
Published: December 2010

In this thesis, the atmospheric pressure nitrogen dielectric barrier discharge (DBD) plasma modified polyproylene (PP) melt blown non-woven surface wettability are investigated. The change of surfaces physical and chemical properties are studied by water contact angle measurement and X-ray photoelectron spectroscopy (XPS) before and after plasma treatment. The experimental results indicate the surface hydrophilic can be greatly improved when the PP simples is treated by atmospheric pressure nitrogen DBD plasma for a short time. And a large number of oxygen-containing and nitrogen-containing functional groups are inplanted on the PP non-woven sample surface.
Study on the Friction Characteristics of Different Lubrication Modes under Alternating Magnetic Field
Authors: Liu Hong Bin , Li Ji Shun , Xue Yu Jun , Ma Wei
Published: December 2010

Magnetic fluid has many advantages when serving as lubricant. With an appropriate magnetic field this lubricant can prevent leakage and increase the load capacity of lubricant film. It can also be fixed at the friction zone by applying an external magnetic field. This paper aims to improve the lubrication performance of friction pairs under alternating magnetic fields. The test was conducted on a NG-x reciprocating friction tester. Test results using the magnetic fluid and those using expanded graphite were compared. The tribo-surfaces were obtained in real time. It is concluded that the magnetic fluid lubricant has better lubricating property than the nonmagnetic lubricant (expanded graphite) because it can cling on friction pairs uniformly, and the endurance magnetic fluid lubricant is better than that of nonmagnetic lubricant.
Parametric Intelligent Design System of Manipulator of 4 DOF
Authors: Li Jing , Zou Xiang Jun , Chen Yin Le , Sun Quan , Chen Yan , Wang Hong Jun
Published: December 2010

In order to realize rapid design, a parametric intelligent design system of picking manipulator (PIDS-PM) of 4 DOF( Degree of Freedom) was developed. The design was reused and became more standard, the development cycle was shortened and the cost was reduced. First, knowledge attribute properties of manipulator were extracted and classified and parameterized according to its functions. They were consisted of a reusable knowledge structure module which included all the information, relationships and maps among parameters. Second, a knowledge repository based on database was constructed, which was used to query the database and obtain the optimal design scheme. Finally, the system was realized by using VC++6.0 including its structure, main function modules, user interface and its design result.
Microscope Measurement of Jet-Pan Based on CCD
Authors: Shao Dong Xiang , Li J. , Lu Ze Sheng , Wang Guang Lin
Published: December 2010

The jet-pan is a key part of jet-pan servo valve. Required precision of jet-pan should be guaranteed in process. CCD microscope measurement is used to deals with the measurement of jet-pan in the paper. The worepiece is enlarged by the optical microscope, and a series of image processing algorithms is used to process the image. The basic dimensions and geometrical tolerance of jet-pan are measured. And the stability error is less than ±0.5μm.
On-Line Prediction Model of Ultrasonic Polishing Surface Roughness
Authors: Zhang Ming , Yang X.Q. , Zhao Bo
Published: December 2010

In order to solve the difficulty of on-line measuring the surface roughness of workpiece under ultrasonic polishing, the artificial neural networks and fuzzy logic systems are introduced into the on-line prediction model of surface roughness. The surface roughness identification method based on fuzzy-neural networks is put forward and used to the process of plane polishing. In the end, the on-line prediction model of surface roughness is established. The actual ultrasonic polishing experiments show that the accuracy of this prediction model is up to 96.58%, which further evidence the feasibility of the on-line prediction model.
Fault Diagnosis of Rotating Machinery Base on Wavelet Packet Energy Moment and HMM
Authors: Zhang Chun Liang , Yue Xia , Li Sheng , Li Jian
Published: December 2010

A feature extraction method is presented for the fault diagnosis of large rotating machinery to improve the performance of on-line monitoring. According to the characteristics of fault vibration signals, wavelet packet decomposition, a well-known tool to multi-scale analysis, is applied to extracting frequency band energy features; and Hidden Markova Model (HMM) is used to classify. The final feature array is composed of time-domain, amplitude-domain features and wavelet packet energy moment features which reflect the inherent energy distribution characteristics of different faults. The continuous density hidden Markov model (CDHMM) is adopted to recognize the state in on-line monitoring, and the diagnosis success rates are more than 91% to six typical faults on different rotation speeds. The experimental results show the fault diagnosis system is valid and robust, particularly the method of feature extraction.
Research on Dynamics Parameter Identification of Limb for Rehabilitation Robot
Authors: Guo Xiao Bo , Zhai Y.
Published: December 2010

Because of rehabilitants with various characteristics, rehabilitation robot must perceive the rehabilitant states(strength and position) and then adopt corresponding training mode and control strategy. So how to obtain the state of a rehabilitative limb correctly is very significant for a rehabilitation robot during the training. A new method of dynamics parameter identification of limb based on BP (back propagation) artificial neutral network is presented to offer rehabilitation robot dependable information of limb. The simulation results prove that the method of parameter identification can achieve the state of a rehabilitation limb veraciously and robustly. It can suit different rehabilitants at different stages of rehabilitation even if a spasm happens during training.
Virtual Assembly System Based on PRO/E and Topological Relationship
Authors: Song J.L.
Published: December 2010

Aimed at building up the virtual assembly for the mechanical system for applications in workshop, with fundamental component lib made by PRO/E modules. Principle of the virtual assembly on PRO/E and topological relationship was put forward and employed for the system as the base. Detailed constraint relations and topological relation were researched in Cartesian coordinate system for guiding wheel consisting of eleven main components. Virtual testing for the assembly quality was provided with the tolerance and fit features of the mating surfaces.
Current Development and Countermeasure of Ultra-Precision Machine Tools
Authors: Song R.J. , Niu J.L. , Chen Dong Hai
Published: December 2010

Ultra-precision machine tools is an important machinery equipment to implement ultra-precision machining. Current development and the trend of the ultra-precision machine tools was analyzed. The factors influencing machining accuracy were pointed out from the viewpoint of system. Some suggestions were put forward on the domestic development and research of the ultra-precision machine tools.
Influence Research on Passivation to Abrasion Behaviour of Coated Milling Cutter Edge of Wheel
Authors: Zhang E.G. , Wu Yan
Published: December 2010

The innovative use of surface shot-peering to make a passivation at milling cutting edge of wheel, it shows that passivation has eliminated all microcrack and abrasion trace on the surface of milling cutting edge through microscopical observation, so as to improve adhesive force among the coating and cutter body, to make an uniform wear of cutter with coating during machine work, and further to keep fairly good function of cutting edge. Furthermore, the milling length of wheel cutter is over 8 meters, and such technology has solved the technology problem in production domesticization of wheel cutter.
Stiffness Analysis for Large-Travel Rotational Butterfly Pivot
Authors: Lu Ya Fei , Zhou Qing Kun , Sheng De Jun , Fan Da Peng , Zhang Zhi Yong
Published: December 2010

Butterfly pivot is a large-travel rotational flexure pivot, which can provide elastic support for the rotational shaft in several ten degrees. Because of the complex structure, stiffness calculation of butterfly pivot is always completed by the method of Finite Element Analysis (FEA), which is not suitable for parameter design and optimization. The serial structure of four-blade isosceles-trapezoid (FBIT)is proposed to simplified the complex structure of the butterfly pivot. The FBIT is analyzed and the theoretical formula of stiffness calculation for rotation stiffness is derived in detail based on the essential theory of Mechanics of Materials. Design and optimization of rotation stiffness for each element can be achieved easily with the obtained the theoretical formula of rotation stiffness. The total rotation stiffness of the whole butterfly pivot is calculated and the rotation stiffness comparison between using the theoretical method and by the method of FEA is performed. The error between the theoretical rotation stiffness and the result of the FEA is less than 10%. It is acceptable and without any influence on the validity of the work and concept presented in this paper.
Thermomechanical Finite Element Simulation of Cutting Force and Temperature in Ultrasonic Aided Turning of Hardened Steel
Authors: Jiao Feng , Zhao Y. , Jian Jin Hui , Liu X.
Published: December 2010

Compared with conventional turning (CT), ultrasonic aided turning (UAT) demonstrates many advantages in turning of hardened steel. In the paper, UAT is studied with finite element (FE) simulations and compared with conventional hard turning according to simulation results. Based on the thermo-elastic-plastic finite element equation for simulating the metal orthogonal cutting process, the paper introduces two-dimensional thermomechanically coupled FE models with and without ultrasonic assistance by means of MSC.MARC FE software. And the differences of cutting force and temperature distribution in the process zone between conventional and ultrasonic hard turning are investigated. Research results show that the mean cutting force and temperature in UAT are smaller than those in CT, UAT is an suitable method for precision turning of hardened steel.
Influence of Prestrain on Output Characteristic of Dielectric Elastomer Film Actuators
Authors: Zhu L.H. , Zhu Xi Lin , E Shi Ju , Hui An Feng , Cao Jian Bo
Published: December 2010

Prestrain affects the performance of dielectric elastomer actuators so much that rare actuators is used before pre-stretching. In this article, the author made a series of circular actuators with acrylic VHB4910 and graphite mixture electrodes, and performed contrast experiments, under non-prestrain, uniaxial prestrain and equibiaxial prestrain, respectively, to figure out the changing of area strain against prestrain. Result of experiment indicates that the film actuator obtains the highest output strain while applying equibiaxial prestrain. An optimum prestrain ratio of actuators, in this research, occurs between 150%~200% under equibiaxial prestrain condition. This result has practical value in the future design and use of dielectric elastomer actuators.
Research on Multi-Axis High Speed Machining Milling Force of Aeroengine Impeller
Authors: Guo Y.Y. , Zhao Can , Du Wei Gang
Published: December 2010

On the basis of the ball-end milling feature during high-speed machining impeller, the relationship between cutting force and chips is analyzed in this paper. The model of ball-end milling cutter cutting force is founded through differential method. And the coefficients solution of cutting force model is expounded. Besides, the coefficients solution and the cutting force model simulation are implemented by the software Matlab.
Modal Test and Analysis of a Bridge under the Varying Temperature Condition
Authors: Liu Yang
Published: December 2010

To consider the effect of varying temperature on dynamic properties of bridge structures, a continuous modal test for a suspender bridge was carried out. Firstly, a long-term modal test is conducted, and the first five modes (frequencies, damping ratio and modal shapes) under different temperature are identified by modal parameter identification. Secondly, the comparison between the analytical dynamic properties and measured results are analyzed, and the changing regularity of this structure under varying temperature is summarized. The results show that the frequencies of this bridge increase as the ambient temperature decrease, and that the damping ratio and modal shapes are not sensitive with the ambient temperature. Finally, the relationship model between the environmental temperature and frequencies of this bridge model is obtained by regression analysis. The confidence interval of undamaged structure is obtained, and then this confidence interval is applied to assess the condition of this bridge.
Study on Finite Element Model of Bridge Multi-Pile Foundation
Authors: Xing Shi Ling , Ye Jian Shu , Sun Hang
Published: December 2010

In order to use finite element software to complete the design or calculation of bridge multi-pile foundation, this paper discusses the finite element model (FEM) of a bridge multi-pile based on the theory and provisions in Code for Design of Ground Base and Foundation of Highway Bridges and Culverts (CDGBFHBC 2007) of china. For the FEM of a bridge-multi pile foundation, cap is regarded as a rigid body, piles are taken as beams, and boundary constraints are a series of horizontal springs and vertical springs. First, the formula of stiffness for horizontal springs and bottom vertical spring is derived according to elastic ground base theory and winkler hypotheses. Secondly, for the friction pile, the stiffness of vertical springs on piles side is derived basis of the principle of friction generated and simplified distribution of pile shaft resistance. Then, the FEM of multi-pile needs pay attention to three issues: the simulation of connections between piles and cap, elastic modulus needs discount, and the weight for pile underneath the ground line (or local scour line) needs calculate by half. Taking pile section bending moment often control the design and calculation of pile into account, this paper gives a simplified FEM of pile. Finally, an example is used to introduce the application of the FEM of bridge multi-pile foundation.
Bridge Significant Failure Mode Identification Strategy under Traffic-Load
Authors: Gao Xin , Qin Wei Hang
Published: December 2010

Increasing axle loads and traffic density made bridge accidents happened very often in China which caused the bridge safety assessment method in dire need. As a method for bridge safety assessment, the structural reliability analysis is widely accepted. An important part of system reliability estimation is to identify the subset of significant failure modes. In this paper, a stage critical strength branch and bound algorithm is proposed for the failure mode identification of bridge systems. The proposed method is implemented in the combination with the finite element package ANSYS and the MATLAB procedure, and is illustrated with the help of a truss bridge example. This algorithm is found efficient and reasonably accurate, and it can be applied to any kind of bridge systems without having to do much additional programming.
Seismic Testing of a Long-Span Concrete Filled Steel Tubular Arch Bridge
Authors: Yan Wei Ming , Li Yong , Chen Yan Jiang
Published: December 2010

Long-span bridges are always a multi-support structural system, and seismic ground motion can vary significantly over distances comparable to the length of such kind of bridges, so it’s difficult to carry out shaking table tests because of the restriction of the dimension and amount of shaking tables. This paper discusses the multiple sub-table cordwood system is used to conduct a study on the seismic testing of a three-span irregular Concrete filled steel tubular (CFST) arch bridge with the objective of investigating the dynamic performance of the bridge under spatial earthquake motions. The development and testing of the bridge model and selected experimental results are discussed then. The seismic response and response characteristics of acceleration, displacement, internal force, and strain of the structure under earthquake excitations are gained, which can provide test data and basis to evaluate the seismic performance of this CFST arch bridge or other similar structural system design.
Solidification Study of Gray Cast Iron in a Resistance Furnace
Authors: Lora Rubén , Diószegi Attila , Elmquist Lennart
Published: December 2010

Solidification of hypoeutectic gray cast iron has been investigated in a resistance furnace. A cylindrical shaped sample with three thermocouples, two inside and one in the surrounding, was solidified and compared to samples quenched at different stages during the solidification interval. An additional sample in the series has been produced to reveal the primary grain structure using Direct Austempering After Solidification (DAAS) treatment. The present paper collect for the first time under the same experimental procedure the solidification of a hypoeutectic gray cast iron where both the growth of the primary and eutectic phase are observed. An increase of the secondary dendrite arm spacing (SDAS) was observed until the end of the solidification interval. A comparison of the measured solidified fractions of the phases with those predicted using Fourier Thermal Analyses evidenced the quenching effectiveness. The eutectic cell size is in agreement with the literature. The method presents good consistency.
New Aspects Regarding the Structure of Spheroidal Cast Iron Carbon Inclusions Revealed by WAXD Investigations
Authors: Pencea Ion , Ştefănescu Doru Michael , Ruxanda Roxana , Anghelina Florina Violeta
Published: December 2010

The paper addresses mainly the atomic structure of the spheroidal carbon inclusions (CIs) from a magnesium treated cast iron. The qualitative phase analysis based on diffraction patterns shows that the CI by-products contain carbon, ferrite and iron oxides. Based on peak angular positions and their half-width at half-intensity, the distances between graphenes and the average height of the graphene stack were calculated. To comply with EN 13005 standard, the calculated results include the extended uncertainties U(95%). The Wide Angle X-ray Diffraction (WAXD) data proves clearly that the CI from the spheroidal cast iron do not have a polycrystalline graphite structure, but rather a turbostratic graphite-like structure with the d(002) surprisingly close to the graphite structure, e.g. to 3.34 Å. If this conclusion is accepted, a new approach of the nucleation and growth mechanisms of the CIs in spheroidal cast irons as turbostratic graphite-like structures should be explored, while the mechanisms based on crystallographic considerations should be revised.
The Influence of Alloying Elements on Chill Formation in CGI
Authors: König Mathias , Svensson Ingvar L. , Wessen Magnus
Published: December 2010

The influence of alloying elements on the chill formation in Compacted Graphite Iron (CGI) is investigated. Chill wedges cast in an industrial foundry were used to investigate the chill formation. A total number of 19 chemical compositions were studied, including three trials of varying nodularity treatment level; four trials of varying copper content; four trials of varying silicon content; four trials of varying tin content and four trials of varying carbide promoter content. Three wedges were cast for each alloy composition, of which one was used for measuring the temperature at three different heights in the wedge. Contrary to some previous reports, the results indicate that low-nodularity CGI is not more prone to chill formation (columnar white) than high-nodularity CGI. Trends regarding the effect of alloying elements on chill formation are shown to generally be in agreement with previous work on spheroidal graphite iron and lamellar graphite iron. Most of the samples also show carbide formation in centre line areas of the wedge (inverse chill), this occurrence is also discussed in the paper.
Effects of Forging and Heat Treatment on Microstructure and Properties of High Boron White Cast Iron
Authors: Zhang Jian Jun , Gao Yi Min , Xing Jian Dong , Ma Sheng Qiang , Li Ye Fei , Liu Li
Published: December 2010

The effects of forging and heat treatment on microstructure and properties of high boron white cast iron were investigated in this paper. The results show that forging breaks up boride network and makes broken boride particles uniformly distributed in matrix. During subsequent heat treatment, spheroidized boride is able to be obtained. The hardness of high boron white cast iron increases slightly (from 51.4 HRC to 54.7 HRC) while the toughness increases obviously (from 5 J/cm2 to 107 J/cm2) by combined process of forging and heat treatment. Fracture morphology changes from brittle fracture to ductile fracture.
Effect of Chromium and Vanadium Contents on Continuous Cooling Transformation Behavior of Multi-Component White Cast Iron
Authors: Yokomizo Yuzo , Yamamoto Kaoru , Sasaguri Nobuya , Matsubara Yasuhiro
Published: December 2010

In this study, the multi-component white cast irons with 5wt% of Mo, W, 2 wt% of C, Co each and varying Cr content from 1 to 9 wt% and V content from 3 to 9 wt% independently were employed and effect of Cr and V contents on the behavior of continuous cooling transformation (CCT) was investigated.
When the Cr content increases to 5wt%, the critical cooling rate of pearlite transformation (VC-P) does not change much, but the VC-P decreases gradually as the Cr content is increased over 5 wt%. The critical cooling rate of bainite transformation (VC-B) increases with an increase in the Cr content. In the case of V effect, on the other hand, the VC-P decreases as the V content increases. However, the VC-B decreases with an increase in the V content up to 4mass%, but over 4wt%V, it increases, and at 9wt%V, the precipitation of ferrite phase occurred.
Ms temperature decreases continuously as the Cr content increases to 5wt%, and then increases. As the V content increases, Ms temperature rises gradually. In the case that Mf point appears, the Mf temperature goes up with an increase in the Cr and V contents.
Wear Characteristics of Spheroidal Carbides Cast Irons in Uniaxial Rotary Glass Shredder
Authors: Yoneta Naoji , Shimizu Kazumichi , Hara Hiroya , Tanaka Masahito , Nawa Yoshihiro
Published: December 2010

Spheroidal carbides cast irons (SCIs) are used in severe conditions where often occur erosion and due to their excellent wear resistance characteristics. In this study, three kinds of SCIs with a variation in matrices are tested and evaluated as shredding blade of uniaxial rotary glass shredder in recycling factories where often occurs extreme abrasion with the crushed glass. They are SCI-VCrNi, SCI-VMn, and SCI-Vw with hard (2400Hv) spheroidal vanadium carbides (VC). As a result, SCI-Vw reveals excellent wear resistance, approximately 1/12 of wear removal in weight, compare to other two materials of SCI-VCrNi and SCI-VMn. Spheroidal carbides nodularity(70%) and volume fraction of VCs(approximately 20%) are similar in three kinds of SCIs. The hardness of matrix of SCI-Vw (800Hv) is greater than that of SCI-VCrNi (320Hv) and SCI-VMn (380Hv). Therefore the experimental results are interpreted that hardness of matrix are dominant factor for abrasion. Based on this experimental study, SCI-Vw is an effective material for abrasion occurred on the blade of the glass shredder.
Influence of Ti on Graphite Morphological Transition in Flake Graphite Cast Iron
Authors: Nakae Hideo , Fujimoto Kyohei
Published: December 2010

The morphological transition from the A-type to D-type graphite (undercooled graphite) in cast iron has been studied using Fe-3.5%C-2.0%Si-0/0.1%Ti samples. The samples were prepared using a high frequency induction furnace flowing Ar atmosphere using 0.25% steel rods with or without Ti addition. The samples had Ti contents that ranged from 0 to 0.10% at 5 different levels by the addition of sponge titanium. The cooling curves of these melts were measured in a shell mold with an inside diameter of 30mm and 50mm height and in four BN-coated steel cup molds with a volume of 30ml each. The cooling curves were measured by CA thermocouples located at the center. The cooling curves were differentiated to determine the transition points, namely the onset and end points of the eutectic solidification. Three out of the four samples, solidifying in steel molds, were quenched during the eutectic solidification and their macro-structures and micro-structures were observed for the determining the solidification mode.
The volume fractions of the D-type graphite area in the samples were measured using 30 microscope images of 50× magnification, and their eutectic temperature was also determined using their cooling curves. The volume fraction of the shell mold samples increased with the Ti addition from 5% to 55%, and if the Ti content was greater than 0.05%, the acceleration occurred with their maximum undercooling, ΔTMAX. The critical undercooling temperature, TA/D, and the critical solidification rate, RA/D, of the A-type to D-type graphite transition were determined by comparing the volume fractions to the solidification time. The ΔTMAX　and TA/D values increased with the Ti addition. This is the main reason why the Ti addition accelerates the D-type graphite increase.
Interface Property and Two-Body Wear Behavior of High-Cr WCI Matrix Composite Reinforced with CC Particles
Authors: Li Ye Fei , Gao Yi Min , Zhang Jian Jun , Yan Jing Bo
Published: December 2010

The vacuum infiltration casting process was adopted to prepare cemented carbide (CC) particles reinforced high-Cr white cast iron (WCI) composite by using failed CC parts as reinforcement. The interfacial structures between the CC particle and iron matrix were analysed by optical microscope (OM) and X-ray diffraction (XRD); the wear behavior of the composite was studied by pin-on-disc wear tester. The results showed that: owing to partial dissolution of the CC particles and diffusion of elements such as W, C, Cr and Fe, compounds such as Fe3W3C and Co3W3C were formed, which ensured metallurgical bonding at the interface; the wear resistance property of the composite was much higher than that of the heat treated WCI, moreover, when the applied load increased from 0.4Kg to 2Kg, the wear resistance value of the composite was more than 3.5 times than that of the heat treated WCI. However, there was no significant difference in the wear loss between CC/WCI composite and WC/WCI composite.
Prediction of Hypoeutectic Gray Iron Microstructure during Solidification and Solid Transformation Using Simple Fourier Model
Authors: Taha Hanafi Mohamed Ahmed , El Mahallawy Nahed A. , El-Sabbagh Ahmed M. , El-Benawy Talat , Hadla Hasan F.
Published: December 2010

Phases’ evolution during the solidification of a hypoeutectic 3.92% C-equivalence cast iron was modelled by considering the cooling history of the alloy from the melt, thus including both solidification and solid state transformations. Simple Fourier model was used to combine macroscopic heat flow and microscopic kinetics for phase evolution. Different cooling rates were obtained by casting cylinders and stepped plates. Measured number of primary austenitic nuclei, eutectic cells and volume fraction of phases during solidification (graphite, a-ferrite, pearlite and cementite), are correlated with the cooling rate. Growth rate constants for primary austenite, are found to be  = 8.7E-7, and n = 2.3. Growth rate constants for primary graphite (types A, B, and C), are found to be  =5.7E-7, and n = 2. The model matches with the experimental work where the error percent of modelling volume fractions of pearlite, graphite, ferrite and cementite ranges between 0.2 and 1.5%.
Modelling the Thermal Conductivity of Various Cast Irons
Authors: Holmgren Daniel
Published: December 2010

The thermal conductivity of five predominately pearlitic grades of lamellar, compacted and spheroidal graphite iron have been modelled by means of existing models based on average field approximations. The model is based on the area fraction of different constituents and the width to length ratio of the graphite. The thermal conductivity of graphite in cast iron is derived by inverse modelling. These data are used in combination with experimental thermal conductivity values for a pearlitic matrix in order to model the thermal conductivity of various cast iron grades with good agreement. The calculations are executed for cast iron from room temperature up to 500°C.
Some Key Points on High Strength Grey Iron Cylinder Block Production
Authors: Li Feng Jun , Cai An Ke , Tang Ding Xiang , Ren Feng Zhang , Dong Hong Li
Published: December 2010

Three key points are discussed to manufacture 300Mpa cylinder block castings. The first one is the design of grey iron chemical composition. The chemical composition used for production is as follows: C: 3.20-3.30%, Si: 1.60-1.80%, Mn: 0.70-1.00%, S: <0.10%, P: <0.06%, Cu: 0.70-0.80%, Cr: 0.25-0.35%, Ni: 0.30-0.40%, Sn: 0.06-0.08%. The stream inoculation is adopted. Another key point is to increase the chilling effect of molding material. A kind of ceramic sand is used in the experiment. The ceramic sand is mainly composed of electric fusion bauxite. The material gives much stronger chilling effect. The tensile strength can be 20 MPa higher compared with ordinary silica sand. The third key point is to use the technology of synthetic cast iron. The 300 MPa cylinder block is successfully developed.
Lubricated Friction and Wear Properties of P-B Bearing Flaky Graphite Cast Iron
Authors: Itoh Toku , Ogi Keisaku
Published: December 2010

Lubricated reciprocating tests were conducted on an SRV tester to investigate effects of stroke and frequency on frictional and wear properties of flaky graphite cast iron used for marine cylinder liner by varying frequency and stroke under a given sliding velocity in boundary and mixed lubrication regime. It was clarified that changes in coefficient of friction were significantly dependent on stroke and frequency: in boundary lubrication, coefficient of friction at steady state showed a lower value at a combination of lower frequency and therefore larger stroke. In mixed lubrication, however, a combination of lower frequency and larger stroke produced a higher friction. In boundary lubrication where no run-in process was observed, higher frequency contributed to producing rougher surfaces resulting in higher friction. In mixed lubrication bordering on boundary lubrication higher frequency promoted run-in, enhancing film formation and lowering friction. Effects of frequency and stroke also reflected on wear, changes in separation voltage between a disk and a ball specimen, which were in accordance with changes in friction.
Wear Property of Ductile Iron Locally Reinforced with Cr-Containing Steel Inserts
Authors: Mayerling Martinez Celis , Valle Nathalie , Lacaze Jacques , Thorbjornsson Ingólfur , Johannesson Birgir , Thorgrimsson Jon Thor , Podgornik Bojan , Vižintin Joze
Published: December 2010

The influence on the wear properties of ductile iron with Cr-containing steel inserts has been investigated before and after austempering. The microstructure of locally reinforced ductile iron, with and without an austempering treatment, has been characterized using optical microscopy, scanning and transmission electron microscopy and secondary ion mass spectrometry. The introduction of such inserts during casting leads to the precipitation of carbides M3C, M7C3 and M23C6 (M stands for Fe and/or Cr) inside the inserts and to M3C and M7C3 in the region surrounding the inserts. After austempering, a partial dissolution of these latter carbides and transformation of the matrix to ausferrite occur. The wear properties of these materials have been evaluated under reciprocating sliding motion using cylinder-on-disc line contact configuration. The results of the present investigation show a better wear behavior of the reinforced material related to the microstructural changes observed.
New Application of High Niobium Cast Iron as a Grain Refiner for Stainless Steels
Authors: Sakaki Hayato , Mizumoto Masayuki , Ohgai Takeshi , Kagawa Akio
Published: December 2010

In order to develop a new application of cast iron, high niobium cast iron has been developed as a grain refiner for stainless steel. High niobium cast iron was prepared by adding pure niobium to a commercial cast iron. Coarse primary niobium carbide crystals were observed in the microstructure of the cast iron. The effect of the high niobium cast iron as an inoculant on the grain size of austenitic and ferritic stainless steels was examined in various experimental conditions. When the amount of the cast iron inoculant more than 3 mass% was added into the steel melt, fine equiaxed grains were observed and grain size was significantly reduced to 210 μm. The results indicate that the high niobium cast iron is effective as a grain refiner for the austenitic and ferritic stainless steels. From the dissolution rate measurement, the grain refining mechanism was proposed.
Effect of Austempering Temperature on High Cycle Fatigue Behavior of an Austempered Ductile Iron (ADI)
Authors: Yazdani Sasan , Sadighzadeh Benam Amir , Avishan Behzad
Published: December 2010

Ductile irons with chemical compositions of Fe-3.6%C-2.6%Si-0.50%Cu-0.51%Ni were cast into standard keel blocks. Austenitizing heat treatment was carried out on test pieces at 875°C followed by austempering at 320, 365 and 400°C for times within the austempering processing window in a salt bath furnace. Rotating bending fatigue tests were performed with Roell Amsler UBM 200™ equipment at 3500 rpm at room temperature. Metallography and X-ray diffraction techniques were used to evaluate the fatigue life. Results indicate an increase of 10, 20 and 24% in fatigue life for specimens austempered at temperatures of 320, 365 and 400°C respectively, compared to that of as cast samples. According to the XRD test results; there is an increase in volume fraction of high carbon austenite by increasing the austempering temperature.
Growth of Eutectic Austenite in Free Graphite Cast Irons
Authors: Rivera Graciela Leonor , Boeri Roberto Enrique , Sikora Jorge Antonio
Published: December 2010

The present work investigates the growth of the eutectic austenite of hypereutectic free graphite cast irons of different graphite morphology.
The study was based on the analysis of several samples obtained from a highly hypereutectic cast iron melt. A hypereutectic melt was used in order to ensure the absence of proeutectic austenite. With the aim of obtaining samples of different graphite morphology but nearly identical chemical composition, the melt was nodularized by using a standard procedure, and different samples were cast after various fading periods. Through this procedure, spheroidal, vermicular and flake graphite samples were obtained
The results show that the eutectic austenite grows dendritically in all samples investigated. Nevertheless, significant differences were found in the size of the solidification units (grains) and in the microsegregation patterns as the graphite morphology changes from spheroidal to flake.
Effects of Iron Powder Addition on the Solidification Behaviour of Hypereutectic Grey Cast Iron
Authors: Chisamera Mihai , Riposan Iulian , Stan Stelian , Anton Irina , Barstow Michael
Published: December 2010

The purpose of the present paper is to investigate the solidification pattern of slightly hypereutectic grey irons (CE = 4.35 - 4.45%) after an addition of a commercial iron powder, and also in a double treatment with inoculation. Chill wedges with a 0.11 - 0.43 cm cooling modulus (CM), from using resin sand and metal moulds, were used along with different thermal analysis cups (CM = 0.75 and 0.43 cm). Relative clear/mottled/total chill measurement criteria were applied. Unfavourable Mn and S contents [(%Mn) x (%S) = 0.016] and a reduced Al residual (0.0015%) led to relatively high eutectic undercooling and chill in the base iron, especially at high cooling rates (CR). With the lower CM of cups, there was more undercooling in the entire solidification range and more difference between irons. Thermal analysis and chill parameter relationships are normal, except only for iron powder treatment and resin mould solidification, where chill is higher for a relatively lower undercooling. Conventional inoculation after addition of iron powder (double treatment) showed a strong graphitizing effect, as these irons had the lowest undercooling and chill levels, in all the irons tested. It reflects the improved properties of (Mn,X)S compounds as nucleation sites for graphite [10]. This paper is the first of two papers reporting on this study.
Wear Rule of TiAlN Coated Cutting Tool when Milling Material with High Hardness at High Speed
Authors: Guo You Dan
Published: December 2010

As a new cutting tool, TiAlN coated cutting tool shows incomparable excellent
performance in milling material with high hardness and high strength at high speed. The study shows
that TiAlN has its unique cutting characteristics and rule in milling materials with high hardness and
high strength in high speed under different milling conditions. This study shall provide reference for
TiAlN coated cutting tool to mill materials with high hardness and high strength through the study on
the wear rule of TiAlN coated cutting tool.