bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Parameter Identification Approach by Experimental Design and Multiple Regressions Method: Application to the Elastoplastic Damage Constitutive Law of a Steel Thin Parts
Authors: Nasri M.T. , Faouzi Slimani , Rezgui Mohammed Ali , Ayadi M. , Cherouat Abel
Published: April 2015

In this paper, a new procedure for the identification of constitutive elastoplastic models coupled with an isotropic damage variable under large strains is presented. It is a statistical approach used for experimental characterization and identification based on a design of experiments of numerical simulations of mechanical characterization tests. The parameters for a reference material are determined by multiple linear regression as a function of shape indices.The material of reference is mild steel E24; it was characterized in a series of tensile tests of thin plate specimens. The Swift hardening law coupled with an isotropic damage variable that was identified by introducing in the established formulations shape indexes extracted from the experimental tension/elongation curves.The number of simulations required for the identification of the parameters of the reference material is roughly 18% of the number required by the inverse method (simplex).
A Comparison of Magnetometry and Relaxometry Measures of Magnetic Nanoparticles Deposited in Biological Samples
Authors: Urbano-Bojorge Ana Lorena , Félix-González Nazario , Fernández Tamara , del Pozo-Guerrero Francisco , Ramos Milagros , Serrano-Olmedo José Javier
Published: April 2015

The Alternating Gradient Field Magnetometer (AGFM) is an instrument whose high sensitivity (10-8 emu) allows the detection of small amounts of magnetic nanoparticles (MNPs) with high accuracy. Over the last few years, different magnetic techniques have been used for in vitro measurements of magnetic nanostructures inside biological tissues. However, in vivo studies about their distribution within the body are very scarce because their dispersion, after being delivered, reduces their magnetic signal and hinders detection. In this paper we compare the longitudinal relaxation time (T1) and magnetization measurements in mice's biological tissues for the tracking of MNPs after of an injection of iron oxide nanoparticles. Furthermore, we have correlated the AGFM data with Fast Field Cycling NMR Relaxometry (FFCNMR Relaxometry) measurements with histological analysis. The results have demonstrated that these techniques are useful for detecting minute amounts of MNPs in excised organs after in-vivo comparable to other more conventional techniques for the measurement of MNPs biodistribution and clearance. Details about the preparation of the in vivo samples, measurement protocol and statistical data processing are given.
Preparation and Characterization of NiO Nanoparticles
Authors: Shahzad Farrakh , Ettinger Karl , Letofsky-Papst Ilse , Weber Julia , Knoll Peter
Published: April 2015

NiO nanoparticles are successfully prepared by sol-gel technique. A systematic change in preparation parameters like calcination temperature, calcination time and pH value has been done in order to study the influence on crystallite size. The prepared samples are characterized by X-ray diffractometer, Transmission electron microscopy, Energy dispersive x-rays analysis and Raman spectroscopy. It is shown that crystallite size mainly depends on the calcination temperature rather than pH value or calcination time.
Structural Characterization of Mechanically Alloyed AlMg-CeO2 Composite
Authors: Skrzekut Tomasz , Kula Anna , Blaz Ludwik , Wloch Grzegorz , Sugamata Makoto
Published: April 2015

A mechanical alloying and hot extrusion method was used to manufacture an AlMg-based composite reinforced by ~9 wt.% addition of CeO2. Structural features of as-extruded and re-melted samples were characterized by SEM/TEM observations and XRD analysis. Highly refined structure with uniform distribution of structural components has been received. It was found that during mechanical alloying and following hot pressing and extrusion of the material the decomposition of CeO2 oxides has been initiated. As result, formation of intermetallic grains of Al4Ce type was observed. Thermal analysis experiments combined with structural characterization allowed to determine the equilibrium state of the AlMg-CeO2 composite structure.
Electrochemical Codeposition of Nickel and Tin from Gluconate Solutions
Authors: Rudnik Ewa
Published: April 2015

Ni-Sn alloys show excellent properties having considerable technological interest. Commercial codeposition of nickel with tin is usually carried out from acidic fluoride-chloride electrolytes, but these are intended to replace by less aggressive baths. In this work codeposition of Ni-Sn alloys from acidic solutions containing sodium gluconate as a cheap and nontoxic complexing agent was carried out. The electrodeposition process was studied using various electrochemical techniques. Cathodic polarization curves have shown that tin (II) ions were reduced under limiting current. Chronoamperometric studies indicated nucleation of the alloys according to the instantaneous mechanism. Equilibrium speciation of the baths was also calculated. Chemical and phase composition as well as morphology of the coatings were investigated. Corrosion resistance of the alloys was also studied.
The Effect of Heat Treatment on Static and Dynamic Mechanical Properties of Rapidly Solidified and Plastically Consolidated RS442 Aluminium Alloy
Authors: Motyka Maciej , Tokarski Tomasz , Ziaja Waldemar , Wedrychowicz Mateusz
Published: April 2015

Ultra-fine grained metallic materials are characterized by higher mechanical properties comparing with their conventional equivalents. However increase in strength under static load is not always accompanied by improved fatigue behaviour. Previous investigations on submicrocrystalline RS442 aluminium alloy produced by plastic consolidation of rapidly solidified flakes in the extrusion process revealed increase in its high cycle fatigue bending strength caused by annealing at 450°C. The aim of present studies was to evaluate the influence of heat treatment – also precipitation hardening – on static mechanical properties (hardness, tensile and yield strength) and fatigue strength of the alloy determined in high cycle stress controlled bending tests. Correlation between microstructure, static mechanical properties and fatigue behaviour was analyzed too.
Continuous Rotary Extrusion (CRE) of Flat Sections from 6063 Alloy
Authors: Mitka Monika , Gawlik Maciej , Bigaj Mariusz , Szymanski Wojciech
Published: April 2015

The study relates to a process of continuous rotary extrusion (CRE), also known under the name of a Conform Process. This method is used more and more extensively for the plastic working of metals and alloys. In CRE, the feedstock is fed into a profiled groove on the rotating extrusion wheel and is pressed by the pressing wheel. The friction of the extruded material against the rotating wheel generates a force that is pushing the material into the deformation chamber followed by extrusion through the die orifice. The extrusion by CRE was performed on an MC-260 device supplied by Meltech-Confex and installed at IMN - OML for processing of the 6063 aluminium alloy. The feedstock was composed of annealed rods. Two parameters were controlled during extrusion: the temperature of the shoe (element of the housing pressing the extruded material to the wheel) and the speed of the driving wheel. The 6063 alloy was extruded using the wheel speed of 2, 5, 10 and 15 rpm and the shoe temperature of 90°C and 105°C. The extruded flat sections were examined visually for continuity and quality of the resulting surface. In the feedstock rod and in the extruded flat sections (before and after heat treatment), the microstructure and grains were examined by light microscopy. Mechanical properties were also determined (static tensile test and hardness measurement). The study shows how the structure and the mechanical properties of the extruded flat sections are changing depending on the extrusion parameters applied. From the 6063 alloy rods extruded by CRE, flat sections of satisfactory quality were obtained. It was found that CRE yields the highest mechanical properties combined with the correct structure and high surface quality when the feedstock is extruded with the wheel rotational speed of 10 rpm and the shoe temperature of 105°C.
The Hammer Forging of Ti-6Al-4V Alloy
Authors: Łukaszek-Sołek Aneta , Bednarek Sylwia
Published: April 2015

In this paper, the research results of hammer forging process of titanium alloy Ti-6Al-4V are described. It is hard deformable alloy so forming details with complex shape from this alloy requires precise selection of thermomechanical parameters. Proper design of technological forging process of forging from Ti-6Al-4V alloy, taking into account the initial metal working, shape of supportive impressions, lubricants with proper tribological properties and also proper selected temperatures of tools and material allows to get the final product without defects. The numerical modelling based on the FE software QForm 3D was carried out. The distributions of temperature, effective strain and material flow kinematics were analyzed. The correctness of the modelling results was verified by the forging test performed in industrial conditions. Hammer forging tests were made in Polish forging plants. The products of good quality were obtained.
Numerical Simulations of Drawing and Redrawing Process of Forming Thin Cylindrical Element from Aluminium Series 3XXX
Authors: Rękas Artur , Latos Tomasz , Budzyn Robert , Kociołek Maciej , Styrna Tadeusz
Published: April 2015

Numerical simulations of drawing and redrawing process of forming cylindrical elements from thin sheets are complicated issues due to the problem with describing finite elements in the complex calculation model. This type of simulation require the creation of the rheological model including the forming limit curve, the true-stress-strain curve and anisotropy defined in various directions. In addition, it is necessary to design optimal geometry of the forming tools. FEM calculations have been performed for 3XXX series aluminum tape in cold-hardening state. The initial data, boundary conditions have been defined, as well as technological data concerning the sheets have been specified experimentally. Numerical analysis of thin aluminum sheet drawing and redrawing process has been analyzed for 3 various sheet thicknesses, i.e.: 0,250 mm , 0,240 mm , 0,230 mm. Currently, the industry uses mainly sheets of 0.250mm thickness. A few manufacturers of beverage cans use sheets of thickness0.240mm while the sheet of thickness 0.230mmis the innovation which manufacturers try to introduce into the industry to minimize the quantity of material. For the selected thickness the clearance between the punch and the die has been calculated as well as the optimum hold-down force. The influence of sheet thickness on the distribution of thinning along generating line has been examined. In order to determine the thinnest possible sheet for obtaining the optimal thickness of the final product, the thinning of drawpiece has been analyzed. Moreover the value of deformations has been compared to FLC curve as well as the intensity of the stresses generated in the bottom and on side walls of the cup has been examined.
The Analysis of Influence of Sheet Properties on the Ironing Process of Thin-Walled Cylindrical Shell Products from Aluminum Alloys
Authors: Rękas Artur , Latos Tomasz , Budzyn Robert , Fijałkowski Marcin , Brodawka Łukasz
Published: April 2015

In industrial practice, where the amount of products produced in a minute is calculated in hundreds of units, the ironing process of thin-walled cylindrical shell products is carried out with very high speed. In the multi-stage forming process it is important to ensure the stability of parameters of the raw material. Properties of input sheets are defined in international standards, but after the rolling process the properties of input tapes may be various while still in the acceptable tolerance. Differentiation of properties of sheets has a significant impact on the progress of the examined process. The multi-stage forming process requires raw material with a high susceptibility to deformation and an adequate level of plasticity margin. In this study tapes of equal thickness and similar chemical composition from various suppliers have been analyzed. Selected aluminum alloys sheet are currently used in Europe in production of beverage packaging. On the basis of uniaxial tension test results, plasticity margin for a selected tape has been determined. Deformation range and plasticity margin have been analyzed in relation to the stability of production process Defining the correlation between identified strength parameters and the stability of production line allowed to examine the impact of plasticity margin for effectiveness and efficiency of the process. In mass production, each break in machine work results in loss of millions of units. The analysis allowed to compare the value of plasticity indicators of the raw tape deformability in the complex process of forming thin-walled cylindrical shell products and influence for increase the efficiency and reduction of defects.
The Analysis of Mechanical Properties of 3XXX Series Aluminum Sheets Used for Beverage Can Production
Authors: Rękas Artur , Latos Tomasz , Budzyn Robert , Furman Andrzej , Siedlik Michał
Published: April 2015

Materials used for the production of aluminum beverage cans must meet strict strength and plastic requirements. Meeting these requirements by manufacturers ensures minimization of defects in optimized production line, trouble-free operation and good efficiency of production. Depending on some factors, such as: chemical composition of the 3104 aluminum alloy, sheet rolling method, lubricant layer and cooling method, the final product may be characterized by different mechanical parameters. In this study properties of six types of sheets from four different suppliers have been measured. Thickness distributions have been analyzed both on the width and length of the supplied coils. Sets of samples have been prepared for the research, cut out from the coil in three directions 0°, 45° and 90° of the rolling direction. On the basis of the uniaxial tension tests, yield strength, tensile strength, elastic modulus and elongation have been determined. The results have been summarized taking into account their variable values depending on sampling directions. Forming limit curves have been defined for the examined sheets. In order to identify the effect of selected data on wall thickness of both final and semi-products, thickness measurements have been conducted for the drawn cups and cans on different forming stages.
The Analysis of Weldability of Profiles Extruded from Powder Mixtures Based on Aluminium
Authors: Rękas Artur , Zasadziński Józef , Kuta Arkadiusz , Latos Tomasz
Published: April 2015

The paper presents the results of a study to designate the optimal conditions for the powder mixtures extrusion through porthole die to ensure high quality welds. Conditions for obtaining the profiles of powder mixtures with a high degree of compaction and good quality welds have been determined based on mathematical and physical modelling. Modelling studies have been confirmed in laboratory and industrial trials.
Implementation of FMEA into Mass Production Process to Identify and Eliminate Causes of Defects
Authors: Rękas Artur , Kurek Magdalena , Latos Tomasz , Milczanowska Katarzyna
Published: April 2015

Each enterprise that concentrates on boosting its position on a market tries to optimize mechanisms of its activity. It can be realized mainly by development in such directions as extending shares on the market, cost reduction, introducing more effective methods of production and risk management. Increasing the level of customers’ satisfaction is reached by use of FMEA (Failure Mode and Effect Analysis) as a tool of continuous development of products and processes realized by conducting their cyclic analyses. Their results build a foundation for introducing new solutions as corrective actions that eliminate causes of defects and at the same time lead to process and product improvement.The advantages of FMEA have resulted in its implementation into nearly every branch of a modern industry, both for unitary and mass production. An example of application of FMEA in mass production is a production process of beverage cans. This process is multistage, extraordinarily precise, technologically complicated and burdened by a great amount of factors that hypothetically can cause defects.The application of proper preventive actions aimed at defining both potential and factual causes of defects is an essential element of increasing the effectiveness a of production line with the simultaneous production cost reduction and boosting the level of customer satisfaction.In the article, the use of FMEA in mass production on the basis of a beverage can manufacturing has been analysed. On its basis, the potential causes of defects have been isolated and eliminated.
Processing of Copper by Equal Channel Angular Pressing (ECAP) – Microstructure Investigations
Authors: Leszczyńska-Madej Beata , Richert Maria W. , Hotloś Agnieszka , Skiba Jacek
Published: April 2015

The present study attempts to apply Equal-Channel Angular Pressing (ECAP) to 99.99% pure copper. ECAP process was realized at room temperature for 4, 8 and 16 passes through route BC using a die having angle of 90°. The microstructure of the samples was investigated by means both light and transmission electron microscopy. Additionally the microhardness was measured and statistical analysis of the grains and subgrains was performed. Based on Kikuchi diffraction patterns misorientation was determined. There were some different types of bands in the microstructure after deformation. The shear bands, bands and in the submicron range the microshear bands and microbands are a characteristic feature of the microstructure of copper. Also characteristic was increasing of the number of bands with increasing of deformation and mutually crossing of the bands. The intersection of a bands and microbands leads to the formation of new grains with the large misorientation angle. The measured grain/subgrain size show, that the grain size is maintained at a similar level after each stage of deformation and is equal to d = 0.25 – 0.32 μm.
Effect of Continuous RCS Deformation on Microstructure and Properties of Copper and Copper Alloys Strips
Authors: Głuchowski Wojciech , Domagała-Dubiel Justyna , Stobrawa Jerzy , Rdzawski Zbigniew , Sobota Joanna
Published: April 2015

The aim of this work was to study the microstructure and mechanical properties of copper, brass CuZn36 and bronze CuSn6 strips annealed and after repetitive corrugation and straightening (RCS) process. The influence of process parameters on the functional properties of strips was investigated. The study found an increase in the yield strength and tensile strength of the material after RCS process. Crystallite size measurement confirmed the presence of nanoscale structures in the studied materials after deformation by RCS process. The used method of plastic deformation is promising for development materials with improved functional properties. The paper presents also the results of numerical simulations of Cu strip after corrugation on groove and tooth rolls and next straightening. Rolling process simulations were conducted using Forge 2011® based on the finite element method.
Influence of Casting Velocity on Structure and Properties of AlFe0,5 Alloy
Authors: Jablonski Michal , Knych Tadeusz , Mamala Andrzej , Palczewski Maciej
Published: April 2015

The effect of iron addition on the structure and properties of aluminium wire rod obtained in the laboratory horizontal direct chill casting process has been analyzed. In addition, the impact of the casting speed on the properties of aluminium bars, containing the 0.5 wt% of Fe, and laboratory wire drawing process has been examined. The addition of iron increase the strength and plasticity of aluminium wire rod in as-cast condition and after wire drawing process, while the electrical conductivity drop acceptable. Moreover, by improving the plasticity of wires became possible to increase the deformability limit, measured by the reduction in the wire diameter by drawing to a level of less than 0.5 mm. Small-diameter wires are used for the construction of automotive wire harnesses, cables battery or winding wires. It has been shown that iron is beneficial for mechanical and technological properties of aluminium, and the horizontal direct chill casting process by graphite crystallizer may be an alternative solution in comparison with industrial scale of continuous casting and rolling by Properzi method (CCR) or Southwire SCR process in the context of the preparation of smaller amounts of material with scrap metals.
The Deposition Rate, Hardness and Tribological Properties of a-C:H Coatings with a Tungsten Filament-Assisted Ionized Reaction Gas
Authors: Kao Wen Hsien , Su Yean Liang , Horng Jeng Haur , Huang Hsi Chuan
Published: April 2015

The a-C:H coatings were deposited on AISI M2 steel disks using an unbalanced magnetron sputtering technique with a single titanium metal target, three graphite targets and mixed methane/ acetylene reactive gas. The various currents (9A-17A) were applied to the tungsten filament to enhance ionization rate of reactive gas. Tribological properties of a-C:H coatings were conducted used reciprocating friction tester. The results show that the tungsten filament current has a significant effect on the deposition rate, hardness and tribological properties of the coatings. With the increase of the tungsten filament current, the deposition rate and hardness of the coating increases, respectively. In sliding against an AISI 52100 steel ball for 24 minutes, all of coatings reduce the wear depth by a factor of at least 11 compared to that observed on an uncoated substrate. The 17A coating yields the best tribological properties that are the minimum wear depth, the lowest friction coefficient and the maximum lifetime when sliding against an AISI 52100 steel ball.
Tribological Characteristics of Diamond like Carbon Coating in the Presence of Environment Friendly Vegetable Based Oils
Authors: Al Mahmud K.A.H. , Kalam M.A. , Masjuki H.H. , Mobarak H.M.
Published: April 2015

Nowadays environmental awareness issue draws the attention of the scientists; lubricant industry also focuses on environment friendly lubricating oils. Therefore, vegetable oils draw the attention of scientists because of environmental friendly as well as good lubricating characteristics. However, good lubricating vegetable oils often shows inferior property because of low thermal stability, hence, to enhance the performance of vegetable oils self-lubricating diamond like carbon coating is considered, which helps in lowering the friction force which in turn lower friction induced heating, as a result stability of vegetable oils increases. In this current research, three vegetable based oils (sunflower, palm, coconut) are considered as lubricating oil. Tribological tests are conducted by ball on plate tribo-testing machine, tetrahedral type diamond like carbon coated plates and uncoated balls are used in the tribo-pair. Among the testing conditions sunflower oil shows good friction and wear characteristics and coconut oil shows inferior friction and wear characteristics.
Development of Mixed Lubrication Cold Rolling Model
Authors: Hwu Yhu Jen , Lee Jian Ting , Jeng Yeau Ren
Published: April 2015

Within past 20 years, high surface qualities of cold strip were demanded by automotive industry and electrical engineering. Main purposes of cold rolling processed are to provide high quality surface and generate appropriate roughness for different customs. Emulsion is a common coolant used in cold rolling processes, Properties of base oil in emulsion, concentration, roughness of work roll, rolling speed and reduction are important parameters, which dominate the surface qualities of cold rolled strip. Hence, a powerful cold rolling model which can describe complicate tribological behavior in roll bite is required. In this article, a cold rolling model which integrates roll deformation and mixed lubrication in inlet zone and biting area was developed. The thickness of oil film, fraction of contact area and coefficient of friction in roll bite are calculated.
Studies of Micro-Hole Burr Improvement for Aluminum Alloy Materials Using Vibrated Abrasive Grinding Machining
Authors: Yang Shie Chen , Yang Shie Chen , Tsai Feng Che , Huang Hsi Chuan
Published: April 2015

This study investigated the removal improvement of micro burrs of aluminum alloy materials using vibrated abrasive grinding machining. The image processing technology is used to examine and quantify the micro-hole burr profiles. The experimental results show that the micro burr was uniformly removed as the workpiece is fixture with vertical direction. In addition, the burr removal improvements are effectively influenced by the flowing velocity and the vibration energy of abrasive particles. The flowing velocities are dependent on the size and gravity of the abrasives and the vibration energy is determined by the material properties and the hardness of the abrasives.
The Study of Thermal Raising and Transmission Torque of High Speed Ball-Screw Lubricated by Different Greases
Authors: Haung Yi , Wei Chin Chung
Published: April 2015

Ball screw is a high-precision and high performance linear drive of mechanical elements. The frictional heat of internal components what is very significant impact for platform transmission in high speed and the high axial load and causes the thermal expansion of element. In this research , the influence of different greases on ball screw is investigated in thermal rising of nut and driving torque in high speed and high axial load. A vertical motion platform was used for driving performance test. Thermal rising of nut of ball screw and the variance of transmission torque whose lubricated by high viscosity base oil grease is significant larger than the lower one. High viscosity grease is not easy to carry out the friction heat generated at ball and raceway contact area due to the bad flowing properties. It also has more serious wear occurred at contact area and high friction force, whose causes the large variance of transmission torque.
Optical Measurement of EHL Film under Oscillating Needle Roller Contacts
Authors: Shen Xue Jin , Song Zhen Min , Chen Xiao Yang
Published: April 2015

In this paper, the EHL oil film thickness and shape between a needle roller and a flat rectangular glass in pure rolling oscillated working conditions had been measured based on optical interferometry. The EHL behavior affected by the applied load, oscillating frequency was investigated. The typical film shape varies of interference pictures on the maximum needle roller rotation velocity was obtained and compared each other. It is found the side constrictions are always the most severe and they are strongly speeds and loads dependence.
Effects of the Nano-Diamond Additives on the Tribological Performance Improvement of Lubricating Grease
Authors: Tsai Ping Hsueh , Chu Hsiao Yeh
Published: April 2015

Ball screw is a very important element in precision machine industry. It has a lot of superior characteristics such as low friction coefficient, long life, high positioning accuracy and as well as converting rotational motion to linear motion. Therefore, the lubricant used in the ball screw should be low friction and wear in order to meet the aims of the above mentioned properties. The ultra-dispersed nanodiamond (UDD) is dispersed in the dispersant. The UDD is served as an extreme pressure additive in the test grease that is applied to the ball screw. Four-ball extreme pressure tests and bearing life tests were conducted in this study to evaluate the extreme pressure performance and durability enhancement of the test grease. The four-ball test results showed that the optimum selection of the dispersant category, UDD mean particle diameter and concentration added to the test grease provided by the cooperated ball screw manufacturer in this study are OLA, 200 nm and 100 ppm, respectively.
A Synchronous Approach for Numerical Simulation of Machine Tools
Authors: Hwang Yunn Lin , Truong Van Thuan
Published: April 2015

In this paper, a synchronous approach for dynamic simulation of machine tools is described. Computer Aided Engineering (CAE) method models and analyzes a dynamical parameter prototype of machine tools. In which, the flexible structure, interactive movement, non-linear factor effects as well as characteristics of resonance frequencies and mechanical transfer function are considered. The integrating Finite Element Method (FEM), Multi-Body Dynamics (MBD) and control carries out a solution of machine tools simulation for predicting dynamic machine behaviors. The static analysis and modal analysis of components are presented with sample examples. Cybernetic characteristics like Bode diagram and such a controller are implemented for movement tailors. The synchronous approach deduces a practically technical method for machines tools.
An Experimental Study on the Tribological Properties of the Pressing Dies of WC and SKD11 in the High Viscosity Oil
Authors: Chang Yuh Ping , Chou Huann Ming , Wang Gino , Wang Jin Chi
Published: April 2015

The poor quality of machining surfaces caused by the surface wear of the pressing dies and the corrosion of the pressing parts has been a major concern for manufacturing engineers. In order to decrease the surface wear of the pressing dies and the corrosion of the pressing parts, the drawing oil is always used during the pressing process. It is well known that the properties and the distributions of the drawing oil significantly influence lubrication, cool down, cleanness and stabilization for the pressing dies and parts. Therefore, it is very important for the operating limitation of the pressing process. This paper is base on the above statements to further investigate the effects of the high viscosity drawing oil on the tribological properties and the adhesions between the dies and parts. The results have not only an added advantage of technology of pressing process, but they are also very helpful in design the pair of the dies and parts in the future. Moreover, the purpose of better quality and faster product speed of the pressing process can then be obtained for the industry.
A Comparative Study on the Tribological Properties for the Automobile Oil Regeneration
Authors: Chang Yuh Ping , Horng Jeng Haur , Ho Te Chuan , Huang Chun Jen
Published: April 2015

Not only fatigue of the metal materials but also inferior quality of the lubricant oils will be occurred for the machines after the long-term operation. Therefore, the self-developed reciprocating friction tester with the measurement system was used to experimental study the tribological properties for the automobile oil regeneration in this study. The major parameters are the reciprocating speeds and the three types of the oil. The ball specimens were made of SUJ2 and the plate specimens were made of SUS304. The variations of friction coefficient and electrical contact resistance were simultaneously recorded during dynamic friction process. After each friction test, the OM was used to observe the worn surface. According to the experimental results, the differences between the new oil, the old oil and the regeneration oil can be clarified. The viscosity, density and color were quite similar for the old oil and the regeneration oil. However, the tribological properties of the regeneration oil were significantly improved. Moreover, it also showed stable during the dynamic friction tests. Even compared with the new oil, the regeneration oil sometimes showed better lubrication under the operation conditions. The wear resistance of the regeneration oil does show great potentials.
Effect of Reheating Process on Microstructure and Mechanical Property of A390 Aluminum Alloy
Authors: Kong Xue , Yang Bi Cheng , Zhang Zhi Feng , Xu Jun
Published: April 2015

The effect of reheating process on the microstructure and mechanical property of A390 aluminum alloy and its evolution mechanism was studied. During reheating process, the microstructure of A390 ingots changed greatly, the microstructure ofα-Al particles changed from dendrite to spherical. As the reheating temperature increased primary Si and eutectic Si gradually grew up and spheroidized while the mechanical properties got the maximum value as the ingot reheating to 540°C. The relationship the between reheating power and microstructure was built. Improving reheating power can restrain the growth of grains, but if the reheating power was too high, the microstructure becomes non-uniform. It has been found that reheating of A390 aluminum alloy experiences two processes of grain combination and Ostwald growing.
Adsorption Behavior of Thiadiazole as Corrosion Inhibitors on Copper Surface
Authors: Xiong Sang , Sun Jian Lin , Xu Yang
Published: April 2015

Adsorption behavior of four typical thiadiazole derivatives as corrosion inhibitors on copper surface both in vacuum and aqueous media, including 1,3,4-thiadiazole-2,5-mercapto (T-SH), (1,3,4-thiadiazole-2,5-diyl) bis (sulfanol) (T-OH), S,S'-(1,3,4-thiadiazole-2,5-diyl) bis (O-hydrogen carbonothioate) (T-COOH) and O,O'-dimethyl S,S'-(1,3,4-thiadiazole-2,5-diyl) bis (carbonothioate) (T-COOCH3), has been theoretically studied using quantum chemistry calculations and molecular dynamics simulations method, and the corrosion inhibition mechanism has been analyzed. The present conclusions have been experimentally verified by corrosion test. Global activity indices indicate that T-OH has the highest reaction activity among the four molecules both in vacuum and aqueous environment. The reaction activity of T-SH is little weaker than T-OH. For the two other molecules, Fukui indices suggest that T-COOCH3 possesses five electrophilic attack centers, which enable multi-center adsorption of the molecule on metal surfaces and thus it has a preferable corrosion inhibition performance compared to T-COOH in vacuum. However, T-COOH has the higher reaction activity in aqueous. At the same time, molecular dynamics results show that T-COOCH3 is more stably adsorbed on copper with surface (110) crystallographic plane than T-COOH does both in vacuum and aqueous environment when the interaction of the inhibitor molecules with four layers of copper atoms is considered. The theoretical results show that the efficiency of the four inhibitors accorded well with experimental results. The study of the questions of oxidation and discoloration of copper surface is to be provided a new method.
Effect of Post-Welded Heat Treatments on Microstructure and Mechanical Properties of Friction Stir Welded Joints of 7A04-O Aluminum Alloy
Authors: Zheng Xiao Mao , Zhang Da Tong
Published: April 2015

Effect of post-welded heat treatment (PWHT) on the microstructure and mechanical properties of friction stir welded 7A04-O aluminum alloy was investigated. Solution heat treatment (ST) and artificial aging (T6) were given to specimens to improve the mechanical properties of the joints. The results show that defect-free joint was obtained via FSW and the microstructure of nugget zone was characterized by fine and equiaxed grains. After ST, most second phases dissolve in the matrix and the α-Al grains became coarse. Second phases precipitated in the α-Al matrix uniformly after T6 treatment. The Vickers hardness test shows that PWHT made the hardness distribution of the joints more evenly. The tensile test results indicate that the tensile strength of the joint increased from 228 MPa (in as-welded condition) to 440 MPa and 528 MPa after ST and T6 treatment respectively, but the elongation decreased to a certain extent. SEM fracture morphologies indicate that the joint failed through ductile fracture for the as-welded and ST states, and failed in a mixture mode of brittle fracture and ductile fracture for the T6 state.
Investigation on the Corrosion Behavior of Emulsion on the Cold-Rolled Silicon Steel Surface
Authors: Li Yan , Sun Jian Lin , Chen Jing Yue , Shi Hao
Published: April 2015

The silicon steel was cold rolled by using an oil-in-water emulsion for lubricating its surfaces. Oil in water (O/W) emulsion is a lubricant composed of oil in the form of droplets suspended in water. This paper mainly researched on the new emulsion which was prepared by changing the compound proportion between antioxidant 2, 6-Di-tert-butyl-p-cresol (T501) and antirust agent petroleum sodium sulfonate (T702). The corrosion behavior of the emulsion was investigated by weight loss and electrochemical methods. The mechanisms for inhibition of corrosion synergism between T501 and T702 in base oil were studied. The results show that the antirust agent (T702) can effectively forming a layer of adsorption film on the rolled strip surface and this adsorption film can segregate strip surface from air and water. The antioxidant (T501) can capture oxygenic free radical (•OH, RO•, ROO•) and carbon free radical and reduces the trend which emulsion occur oxidation reaction under high temperature and high pressure. The antioxidant plays a minor role in inhibition of corrosion synergism. The results show that the best compound proportion content is 4% antioxidant (T501) and 8% antirust agent (T702), which can effectively increase the anticorrosion effect of emulsion. Meanwhile, the self-corrosion potential and self-corrosion current of the sample is minimal and the self-corrosion current is 1.0226×10-7A/cm2.
Microstructures and Mechanical Properties of High Strength Low Carbon Bainitic Steel
Authors: Yang Xiao Long , Xu Yun Bo , Tan Xiao Dong , Yu Yong Mei , Wu Di
Published: April 2015

Based on TMCP and UFC technology, the microstructures and mechanical properties of 0.05% C bainitic steel were studied in this paper. The bainite morphology and precipitation within bainite lath were observed by SEM and TEM, and the mechanical properties of bainitic steel were measured by tensile and impact test. The results showed that the yield and tensile strengths of steel were 713 MPa and 891 MPa respectively, and the elongation was 15.8% with impact energy of 95J at the temperature of-20°C as the final cooling temperature in hot rolling of 550°C. For comparison, the steel obtained the yield strength of 725 MPa, tensile strength of 930 MPa and elongation of 18% as the final cooling temperature of 450°C. However, the impact energy of steel was 195J at the temperature of-20°C. While at the same final cooling temperature of 450°C, the fast cooling-holding temperature-fast cooling was applied to experimental steel with a faster cooling rate of 50°C/s, hence the steel acquired the yield strength of 845 MPa, tensile strength of 1037 MPa, and elongation of 15.5% with impact energy of 168J at the temperature of-20°C. The strength and toughness of 0.05%C bainitic steel is related to the bainite morphology and precipitation distribution. Hence, the strength and toughness can be improved by control the different cooling processes for adjusting the content of lath bainite, distribution of granular bainite and precipitation.
Dendritic Growth Characteristics of Cu-Rich Zone within Phase Separated Fe50Cu50 Alloy
Authors: Luo Sheng Bao , Wang Wei Li , Li Liu Hui , Xia Zhen Chao , Wei Bing Bo
Published: April 2015

The undercooled Fe50Cu50 alloy experiences a metastable liquid phase separation and separates into a Fe-rich zone and a Cu-rich zone within the gravity field. The growth characteristics of the Cu-rich zone were investigated by the glass fluxing method, and the achieved undercooling range was 20−261 K. The volume fraction of the Cu-rich zone decreases with the enhancement of the bulk undercooling. The microstructural morphologies of the Cu-rich zone are similar at all the undercooling conditions, that is, αFe dendrites and particles are distributed inside (Cu) phase matrix. The secondary dendritic arm spacing of αFe dendrites decreases with the increase in bulk undercooling. The growth mechanism of αFe dendrites was analyzed by using the LKT/BCT dendritic growth theory. The dendritic growth in the Cu-rich zone is mainly controlled by solute diffusion so that the dendritic growth velocity is only several millimeters per second. Besides, the calculated results indicate that there is only inconspicuous solute trapping during the solidification of Cu-rich zone.
Study on Composite Interface of 4045/3003 by Cladding Casting
Authors: Han Xing , Shao Bo , Zhang Hai Tao , Qin Ke , Cui Jian Zhong
Published: April 2015

With the cladding casting equipment, which was self-designed and self-made, 4045/3003 composite ingot, which is in size of Φ140mm/Φ110mm, has been manufactured by direct cooling continuous casting by adjusting and optimizing the technological parameters. The process was investigated involving macro-morphology and microstructure near the interface between the two different aluminum alloys at different positions, and distributions of both components and hardness of the cladding ingot. In addition, the tensile strengths were tested. The results showed that metallurgical bonding of two different aluminum alloys could be obtained by direct-chill semi-continuous casting process. The diffusion layer, which is about 15μm on average, has formed on the two sides of composite interface during casting process. From the side of 4045 aluminum alloy to the side of 3003 aluminum alloy, the Si content has a trend to decrease, as well as the hardness, while the Mn content has a trend to increase gradually. Tensile strength of the coated ingot reaches 117.3MPa, which is higher than the core-material matrix (3003 aluminum alloy), indicating the bonding of the two alloys belongs to metallurgical bonding.
Effect of Ti Element on Microstructure and Properties of Cu-Cr Alloy
Authors: Zhang Peng Chao , Jie Jin Chuan , Gao Yuan , Wang Tong Min , Li Ting Ju
Published: April 2015

The Cu-Cr and Cu-Cr-Ti alloy plates were prepared by vacuum melting and plastic deformation. The effect of slight Ti element on microstructure and mechanical properties of Cu-Cr alloy was discussed. The result shows that Cr particles with spherical shape precipitated from Cu matrix after aging. Plenty Ti atoms dissolved in the vicinity of Cr particles and there were still parts of solid solution Ti atoms in other regions. Improvements in peak hardness and softening resistance were achieved with the addition of Ti element in Cu-Cr alloy. The addition of 0.1 wt.% Ti element makes Cu-Cr alloy possess tensile strength of 565 MPa and hardness of 185.9 HV after aging at 450 °C for 120 min, which can be attributed to multiple strengthening mechanisms, i.e. work hardening, solid solution strengthening and precipitation strengthening.
Effect of Multi-Forging Condition on Deformed Structure and Mechanical Properties of A 99.995 Percent High Purity Aluminum
Authors: Zhu Qing Feng , Wang Wen Jing , Zhao Zhi Hao , Zuo Yu Bo , Cui Jian Zhong
Published: April 2015

A purity of 99.995% high purity aluminum was deformed by multi-forging with different conditions (forged by different forging passes with and without water cooling). The effect of multi-forging on macrostructure and mechanical property of the high purity aluminum was investigated. The results show that the deformation heat during the MDF process can obviously affect the recrystallization of the high purity aluminum. Recrystallization occurs in the easy deformation zone of the sample as forged by 3 passes at room temperature. While, when the sample are cooling by water for each pass, no recrystallization occurs in the whole sample as forged by 9 passes. When the high purity forged at room temperature, the structure difference between the easy deformation zone and stagnant zone can not be eliminated by increasing the forging pass to 9. While, the area of the recrystal grain extends with increment of the forging pass.
Comparison Study on Friction-Welded Cu-Al Material and Pure Cu/Al
Authors: Qiao Li , Yang Hui Huang , Sheng Jian Feng
Published: April 2015

Friction-weld Cu-Al has many potential applications to replace the traditional Cu or Al conductor as it has the superior performance and low cost. For ensuring the reliability of Al/Cu metal joints, the mechanical, electrical and long-term properties were investigated by comparing the properties of Cu and Al. The results show that the mechanical properties (tension, impact and hardness) of friction-welded Cu-Al are between the values of Cu and Al, and the welding seam is not the weakest part in mechanical. The electrical resistance of Cu-Al is also between the values of Cu and Al, and does not increase after long-term vibration test and high-low temperature cycle test. The welding seaming is a weak part for salt spray test, it is better to be protected for use.
Influence of Work Media on Surface Property of Compacted Graphite Cast Iron Processed by Laser Local Processing
Authors: Liu Yan , Zhou Hong , Cheng Jing Yan , Yang Chun Yan , Zhang Peng
Published: April 2015

In order to enhance surface property of brake materials, compacted graphite cast iron (CGI) with non-smooth surface was processed by laser local processing. This study focuses on the influence of the work media on wear resistance and thermal fatigue resistance of specimens. The results showed that when the work media were air and water respectively, laser local processing could enhance surface property of CGI. Changing work media could not change phase compositions of the laser processing area, but refined their microstructures, which enhanced their micro-hardness. By this way, the specimens’ wear resistance and resistance to thermal crack initiation were further improved, while their resistance to thermal crack propagation was influenced by cracks on bionic units.
Effect of Pulse Current on the Plastic Deformation Behavior of Tungsten
Authors: Hu Lin , Yang Jian Can , Zhu Wen Guan , Cao Jie
Published: April 2015

The influence of the current density and frequency on the mechanical behavior of the W-CeO2 rod was studied during tension tests in which electric current was applied to the deformation workpiece. A larger decrease in material flow stress and great improvement in the formability were observed in electrically assisted tests compared to the normal tests. The scanning electron microscopy observation showed that the fracture mechanism of tungsten material changed from brittle fracture to ductile fracture, and the second phase fractured, which even became spheroidizing shape.
Grain Refinement of Pure Al by Inoculation and Rotating Magnetic Field
Authors: Chen Hang , Li Shi Chao , Zhang Jun Jia , Jie Jin Chuan , Ma Hong Jun , Li Ting Ju
Published: April 2015

This study aims to understand the grain refinement behavior of commercial purity Al under the influences of inoculation and rotating magnetic field (RMF). Effects of RMF with magnetic flux density of 6mT on the refinement potency of Al-5Ti-1B were investigated. The experimental results indicate fading effect is obvious after adding 0.2 wt.% Al-5Ti-1B into Al with the holding time of 20 min. However, the fading effect can be eliminated to a great extent when RMF was applied to the inoculated Al until the temperature decreased to 662 °C. Meanwhile, the grain size can be further reduced. Compared to the grain size of pure Al under RMF until the temperature decreased to 662 °C, the grain size is coarser when applying RMF to the inoculated Al until solidification, which can be ascribed to the Joule heat produced by RMF.