Easy Deformation Research Articles

5083铝合金热压缩过程的有限元模拟研究

采用Gleeble-3800热模拟试验机对5083铝合金进行热压缩实验，并利用有限元分析软件DEFOM-3D对5083铝合金在变形温度为400℃应变速率为1 s−1，变形温度为400℃应变速率为10 s−1，变形温度为500℃应变速率为1 s−1条件下热压缩过程进行数值模拟，利用后处理程序，分析了合金内部的应变场、应变速率场、应力场和温度场变化。研究表明：5083铝合金热压缩过程具有明显的变形不均匀性，试样分为易变形区、难变形区和自由变形区；为了合理预测再结晶晶粒尺寸，需对实验数据进行修正。 The hot compression of 5083 aluminum alloy was carried out on Gleeble-3800 thermal simulator. The hot compression process at a strain rate of 1 s−1 and temperature 400˚C, strain rate of 10 s−1 and temperature 400˚C, strain rate of 1 s−1 and temperature 500˚C of 5083 aluminum alloy was simulated in the finite element analysis software DEFOM-3D. The variation and distribution of strain, strain rate, stress and temperature in the compressed work piece were analyzed by the post-processing procedures. The results show that the hot compression of 5083 aluminum alloy exhibits a nonuniform characteristic and the specimen is divided into easy deformation zone, hard deformation zone and the free deformation zone. The temperature has gone up during the hot de-formation process, and the experimental data need to be modified in order to reasonably predict recrystallization grain size.

Analysis of 45 Steel Rectangular Thin-Walled Parts Milling Deformation

Aiming at the problem that the machining accuracy of 45 steel rectangular thin-walled parts are difficult to ensure because of poor rigidity, poor manufacturability and easy machining deformation, it used the three-dimensional finite element method, determined the material model of 45 steel and established a prediction model of 45 steel rectangular thin-walled parts milling deformation. The prediction results display that the deformation of the workpiece shows obvious parabola in length direction and a linear decreasing trend in width direction. It verifies the correctness of the prediction model through milling experiments and provides the method and basis for the prediction and control of machining deformation of 45 steel thin-walled parts.

Hermetic Seal Bonding at Low-temperature with Sub-micron Gold Particles for Wafer Level Packaging

Au/Au hermetic sealing was successfully done using a rim structure covered with sub-micron-size Au particles by low-temperature thermo-compression bonding. The easy deformability of sintered Au particles is advantageous in terms of the compliance with surface irregularity as well as the insensitivity of surface flatness. From the deflection of Si diaphragms over the sealed cavity, an inside pressure of 100 Pa and the maximum leak rate in a range of 10−14 Pa·m3/s (He) were estimated, which is sufficient for many MEMS applications.

Equivalent self-adaptive belt grinding for the real-R edge of an aero-engine precision-forged blade

Because of the special characteristics of aero-engine precision-forged blade edges such as heat-resistant and high-strength materials, the unequal distribution and small removal allowance, and easy deformation in processing, edge profile shape errors are easily caused by using conventional processing methods. These errors include chamfered, sharp, flat, and obtuse edges and cervical part shrinkage, so the real-R shape of the edge is difficult to guarantee, and the aero-engine air dynamic performance is seriously affected. The purpose of this research is to improve the dimensional precision, profile shape errors, and surface quality of the real-R edge of the precision-forged blade. With these aims, the method of equivalent self-adaptive belt grinding (ESBG) using a cubic boron nitride (CBN) belt is developed in this study. First, the grinding characteristics and process planning to the blade real-R edge are analyzed. The methodologies of equivalent belt grinding (EBG) and ESBG using a CBN belt are then illustrated, the control equation for EBG is established, and the method of force adaptive control is introduced. Finally, the ESBG method using the CBN belt is verified by experimental investigation of the aero-engine precision-forged blade and comparison with manual and EBG methods. The experimental results showed that the ESBG method using the CBN belt achieved the requirements of the aero-engine precision-forged blade real-R edge. It was verified that the method of ESBG using the CBN belt has the advantages of real-R shape dimensional precision and surface quality for the blade edge compared with the conventional method.

Effect of Multi-Forging Condition on Deformed Structure and Mechanical Properties of A 99.995 Percent High Purity Aluminum

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.

Design of a Clamping Device for the Free Curve Welding

Developing a clamping device fixed directly on a multi-degree of freedom robot manipulator to solve the problem of easy deformation of sheet metal plates in three dimensions free curve is still very challenging. This work describes the conceptual design, the mechanical design, and the design of control system of a new clamping device for the free curve welding. The basic function of the clamping device is to provide a stable and adjustable mechanical pressure which is generated by a compressed conventional spring to a sheet plate in the welding process. Following the concept design stage, the mechanical design is performed, aimed at effectively controlling the deformation of sheet metal and eliminating the gap between the plates in the welding process. Finally, the control methodology is put forward. Thanks to the proposed modular construction and the use of a conventional spring, the device shows good performances. The developed clamping device can also be extended to other applications in surface manufacturing such as spray painting on space free curve.

Plasticity and thermal recovery of thin copper wires in torsion

Experiments in small-scale plasticity usually focus on small-sized samples. However, studying thin wires with lengths up to metres in torsion has the advantage of giving extremely high strain resolution and reversal of the loading direction. In this way, we explore the early stage of plasticity. Microstrain plastic deformation, dislocation creep and the Bauschinger effects are easily observed. The onset of irreversible deformation was observed and associated with a few dislocations in the largest grains throughout the wire. Easy plastic deformation on reversal of the loading direction was observed following this initial plastic deformation but not before.

Study on the Earthquake Resistance Detection System of High-Rise Residence

The earthquake resistance detection method for high-rise residence is researched in this paper. Traditional earthquake resistance detection does not take into account the non-fixity of high-rise residence materials, resulting in easy deformation when residential material is borne the large impact force, thus affecting the earthquake resistance of high-rise residence. To solve this problem, an earthquake resistance detection method for high-rise residence based on maximum entropy algorithm is proposed. According to the strength of impact force that the residential building materials can be borne, the pressure-bearing detection model of residential building materials is established. Using the maximum entropy method can calculate the deformation rule of fixed high-rise building materials caused by pressure-bearing. Thus, the earthquake resistance detection of high-rise residence can be completed.

The Structure Evolution of a 99.995 Percent High Purity Aluminum during Multi-Forging Process in Room Temperature

In this study, a purity of 99.995percent high purity aluminum was multi-directionally forged up to a maximum cumulative strain of 4.5 at room temperature. The macro and micro structure evolution in the multi-directionally forge process was investigated by structure observations and hardness measurements. The results show that the inhomogeneous deformation of multi-directional forging results in that the structure and hardness is quite different between the easy deformation zone and stagnant zone. Dynamic recrystallization occurs in easy deformation zone of high purity aluminum sample at room temperature as the cumulative true strain is 1.5 (3 forging passes), while the structure in the stagnant zone is still not recrystallizated even at a cumulative true strain of 4.5 (9 forging passes). The recrystallized grain size in the easy deformation zone is reduced with the number of forging passes, and the area of recrystallize grains increase with the number of forging passes.

How does epoxidized soybean oil improve the toughness of microcrystalline cellulose filled polylactide acid composites?

Chemical effect is mainly utilized to induce the accumulation of epoxide soybean oil (ESO) on the surface of microcrystalline cellulose (MCC) particles as the formation of flexible layer to produce superior toughness of polylactide acid (PLA) composites. MCC is firstly maleated to produce appropriate chemical reactivity with ESO and thus ESO is induced to form a flexible layer around MCC particles by chemical reaction happened in melt-blending, which is proved by the results from XPS and contact angle measurements. This flexible layer increases the interfacial adhesion and provides an easy deformation region. As a result, high toughness is provided. The elongation and impact strength of PLA/ESO/MCC ternary composites can be respectively improved to 38.5% and 31.7 KJ/m(2). This particular structure also helps to increase plasticization effect leading to a slightly decrease in T-g. The whole process elaborates a simple but an effective methodology to improve the toughness of PLA/cellulose composite in virtue of chemical effect. Toughness of PLA/ESO/MCC composites can be also controlled by the degree of chemical reaction (adjusted by the substitution degree of MA on MCC). Fully biodegradable PLA/ESO/MCC composite with high toughness is finally fabricated. (C) 2013 Elsevier Ltd. All rights reserved.

The Performance Test and Analysis of Sorona Elastic Swimsuit Fabric

The common swimsuit fabrics on the market are mainly polyamide/ spandex, polyester/ spandex blended at present, which have some defects such as easy deformation, short service life etc. Sorona is a new kind of biomass fiber with low carbon and environmental protection, which has more superior performances than spandex that could ensure the fabric elastic lasting and stable. The paper uses seamless technology to weave new polyamide/ Sorona/ spandex swimsuit fabric, and compare with the ordinary polyamide/ spandex, polyester/ spandex fabric, by testing the specimen of tensile elasticity, elastic recovery and plasticity deformation rate, burst strength, and many other swimsuit related performance metrics. Come to conclusions: polyamide/ Sorona/ spandex fabric with superior elasticity, good comprehensive performance of elastic recovery and plastic deformation rate, excellent burst resistant performance , small hygroscopicity and fine permeability is suitable for swimsuit fabrics, providing reference for the development of high comfort seamless swimwear fabric.

Design of an Extrusion and Heat Setting Machine for Needled Filter Felts

The setting process of the needling filter felt by heat can control its flatness and cohesion and can ensure its filtering precision. Based on this, the new type of needling process and the new type of heat treatment technology were developed, the setting arc structure and heat preservation measures were designed, the main roller working system for setting and driving motor system were designed, and they have been put into production. The comparative experiment results show that this device overcomes such defects as surface roughness, easy deformation, breathable unevenness, low intensity and short cycle in the traditional filter felt, which can complete the two processes of extrusion and heat setting for once, and the filtration precision, setting efficiency and the rate of qualified products have improved obviously.

A new equation for estimating the maximum surface settlement above tunnels excavated in soft ground

Nowadays, due to urbanization and population increase, need for metro tunnels, has been considerably increased in urban areas. Common characterization of urban area tunnels is that they are excavated in very shallow depths and soft ground. In such excavations, main challenge for tunneling is low bearing capacity and easy deformation characteristic of the ground. Tunnel face instability and the potential surface settlement are the most hazardous factors that should be considered in all tunneling methods applied in urban areas. Incorrect estimation of the maximum surface settlement value can lead to irreparable damages to the buildings and other nearby structures. There are several published relationships concerned with field measurements and analytical solutions to estimate the amount of the maximum surface settlement value due to tunneling. These relationships are not precise for calculating the aimed values. Therefore, providing accurate equations for estimation of these values is certainly useful. First purpose of this study is to determine the effective parameters such as geotechnical factors (cohesion, internal friction angle, density, Young’s modulus and Poisson’s ratio), and engineering factors (tunnel depth, tunnel diameter and face support pressure) on the maximum surface settlement value. In this study, three metro project constructions namely Istanbul, Tehran, Mashhad in the Middle East were chosen. FLAC3D (Itasca Consulting Group 2002) was used for detailed numerical analysis. The second aim is to present better equations in estimating the maximum surface settlement-based actual data set from several tunnel projects and numerical modeling. The results from the new estimation equation are compared with results of empirical and field observations. The maximum surface settlement values obtained from the new equation have good agreement with the actual results for three different metro case studies.

An Application Research into the Different-Material Insertion in Knitting Clothing Design

Knitting cloth is composed of coils, boasting the characteristics of large flexibility, retractility, and easy deformation, which results that its making and handling is greatly different from that of woven cloth, so that the proper utility of different-material insertion in knitting clothing is capable of fostering strengths and circumventing weaknesses. The present paper starts with the functionality features of knitting and woven fabrics, and their functionalities of dressing, namely, style, color, material, carries out an inductive analysis and thereotical exploration, and finally presents thereotical reference and instruction for the innovative design and development of knitting clothing.

The Design of Tension Control System in Production of the Energy-Saving Windows Film

Aiming at the problem of easy tensile deformation of PET film in production process of the energy-saving windows film, the paper presents control requirements of constant tension, constant line speed during the winding and unwinding. Firstly, the article gives a brief analysis of the tension cause and dynamics equation, and then establishes a mathematical model of the process of unwinding. Finally, starting from the model, the paper designed a control scheme to meet the constant tension, constant line speed using PLC and inverter technology. The field operation proves that the control system has achieved the expected effect of the control.Key words: Energy-saving Windows Film;Tension Control;PLC;inverter technology

INFLUENCE OF DEFORMATION TEMPERATURE ON HOT DEFORMATION BEHAVIOR OF COLD SPRAYED 304 STAINLESS STEEL COATING MATERIAL

The dense 304 stainless steel coating material was fabricated by cold spraying tech- nology. The influence of deformation temperature on hot deformation behavior of cold sprayed 304 stainless steel coating material was investigated by thermo-mechanical simulator. The re- sults showed that deformation resistance of cold sprayed 304 stainless steel coating material re- duced with the increment of deformation temperature. The steady-state deformation resistance reduced from 315.4 MPa to 187.9 MPa when deformation temperature increased from 1000 to 1150 with deformation rate 20 s 1 and deformation reduction 17.5%. The microsturcture of de- formation sample might be divided into easy, difficult and free deformation zones. The area of easy deformation zone increased and area of difficult deformation zone decreased when deformation temper- ature increased from 1000 to 1150 . Recrystallization occurred at free deformation zone without cracking at 1150 . DSC curve showed that phase transition of cold sprayed 304 stainless steel coating material occurred at 1237—1265 . The microhardness of cold sprayed 304 stainless steel coating ma- terial was 313.3 HV0.2, which was relatively high. The microhardness of deformation samples reduced from 332.8 HV0.2 to 244.8 HV0.2 as the deformation temperature increased from 1000 to 1150 with deformation rate 20 s 1 and deformation reduction 50%. The hot temperature deformation

Consolidation of the Cu46Zr42Al7Y5 amorphous ribbons and powder alloy by hot extrusion

The amorphous Cu46Zr42Al7Y5 alloy presents large supercooled liquid region (ΔTX = 100 K), with a viscosity of about 106 N.s/m2 where the material can flow as a liquid, making it possible an easy deformation in this temperature region. The aim of this work was to analyze processing routes to produce bulks of metallic glasses. Two kinds of materials were used: amorphous powders and ribbons, both were consolidated by hot extrusion in temperatures inside the range between Tg and Tx, with a ram speed of 1 mm/min and extrusion ratio of 3 : 1. Analysis of X-Ray Diffratometry (XRD), Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM), revealed that the proposed consolidation routes were effective to produce large bulks of amorphous materials, even with the strong decreasing of ΔTX observed after deformation by milling and during extrusion.

Wettability of Amorphous Diamond-Like Carbons Deposited on Si and PMMA in Pulse-Modulated Plasmas

Pulse-modulated direct-current methane plasmas are used to deposit amorphous diamond-like carbon films on Si and dentistry-use polymethyl methacrylate (PMMA) substrates as a function of the negative pulse voltage applied to the substrate (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> ). The films on PMMA show a transition from diamond-like to more graphitic carbon in the Raman spectra with increasing V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> , dissimilar to those on Si. This is attributed to easy deformation of PMMA, leading to the low compressive stress of the films (1 to 2 GPa). The contact angle of water for the films on both Si and PMMA is large, ranging from 79° to 94° almost independent of V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> , confirming that the films are hydrophobic despite the difference in carbon bonding state. The large dispersion component (41-43 mJ/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) of the surface free energy of the films measured from the contact angle of water and 1-bromonaphthalene indicates the high mass density of the films. The small polar component (0.2-3.5 mJ/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) is attributed to hydrogen saturation of the surface sites forming nonpolar C-H bonds and, thus, responsible for the hydrophobic behavior.

Creep Rupture Ductility of Creep Strength Enhanced Ferritic Steels

Creep rupture strength and ductility of creep strength enhanced ferritic steels of Grades 23, 91, 92, and 122 was investigated with particular emphasis on remarkable drop in the long-term. Large difference in creep rupture strength and ductility was observed on three heats of Grade 23 steels. Remarkable drop of creep rupture strength in the long-term of T91 was comparable to those of Grades 92 and 122. Remarkable drop in creep rupture ductility in a stress regime below 50% of 0.2% offset yield stress was observed on Grade T23 steel, however, that of Grade P23 steel did not indicate any degradation of creep rupture ductility. Higher creep rupture ductility of Grade P23 steel was considered to be caused by its lower creep strength than that of T23 steels. Creep rupture ductility of Grades 92 and 122 steels indicated rapid and drastic decrease with decrease in stress at 50% of 0.2% offset yield stress. Stress dependence of creep rupture ductility of Grades 92 and 122 steels was well described by a ratio of stress to 0.2% offset yield stress, regardless of temperature. On the other hand, large drop in creep rupture ductility of Grade 91 steel was observed only in the very low-stress regime at 650 °C. Alloying elements including impurities and changes in precipitates may influence on creep rupture ductility, however, remarkable drop in ductility of the steels cannot be explained by chemical composition and precipitates. High ductility in the high-stress regime above 50% of 0.2% offset yield stress should be provided by easy plastic deformation, and it has been concluded that a remarkable drop in ductility in the low-stress regime is derived from a concentration of creep deformation into a tiny recovered region formed at the vicinity of grain boundary.

Flax‐fabric‐reinforced arylated soy protein composites: Brittle‐matrix behavior

AbstractBiocomposites were successfully prepared by the reinforcement of soy protein isolate (SPI) with different weight fractions of woven flax fabric. The flax‐fabric‐reinforced SPI‐based composites were then arylated with 2,2‐diphenyl‐2‐hydroxyethanoic acid (DPHEAc) for 4 h to obtain arylated biocomposites. A new method was proposed to determine the amount of carbon dioxide evolved during the arylation of the soy protein in the presence of DPHEAc. Characterizations of the arylated and nonarylated biocomposites were done by Fourier transform infrared spectroscopy, thermogravimetric analysis, and dynamic mechanical thermal analysis. The results indicate that the arylated soy‐protein‐based composites exhibited mechanical behavior like brittle‐matrix composites, which differentiated them from nonarylated soy‐protein‐based composites, which showed mechanical behavior similar to polymer–matrix composites. In the arylated composites, there was clear evidence of a stick–slip mechanism, which perhaps dominated and, therefore, prevented easy deformation of the reinforced film. Scanning electron microscopy studies revealed cracks in the arylated soy protein composites when they were subjected to tensile tests. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012