3,885 results match your criteria deformation metal

Effect of freezing-thawing cycles on the strength and pollutant leachability of stabilized/solidified metallurgical waste.

Environ Sci Pollut Res Int 2021 Apr 30. Epub 2021 Apr 30.

Department of Environmental Engineering, Fırat University, 23119, Elazığ, Turkey.

Stabilized/solidified hazardous wastes may lose their structural integrity and stability when exposed to long-term extreme weather conditions, such as repeated wetting-drying and freezing-thawing (F-T). This situation causes wastes to become environmentally risky again even if they are stabilized and solidified. In this study, the effects of F-T cycles on the strength and pollutant leachability of stabilization/solidification (S/S) products of zinc extraction residue (ZER) stabilized/solidified by Portland cement (PC), fly ash (FA), and alkaline phosphate (AP) were comprehensively investigated. Read More

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Theoretical Justification of Single-Ended Dislocation-Source-Controlled Deformation of Micropillar fcc Crystals.

Phys Rev Lett 2021 Apr;126(15):155501

Institute of Industrial Science, The University of Tokyo, Meguro-ku, Tokyo 153-8505, Japan.

It was established at the beginning of the 21st century that the critical resolved shear stress of small-sized (diameter from 50 nm to 10  μm) metallic crystals fabricated from bulk crystals increases drastically with decreasing specimen diameter. Dou and Derby [Scr. Mater. Read More

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Solution-Processed Stretchable Ag S Semiconductor Thin Films for Wearable Self-Powered Nonvolatile Memory.

Adv Mater 2021 Apr 30:e2100066. Epub 2021 Apr 30.

Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.

Compared with the large plastic deformation observed in ductile metals and organic materials, inorganic semiconductors have limited plasticity (<0.2%) due to their intrinsic bonding characters, restricting their widespread applications in stretchable electronics. Herein, the solution-processed synthesis of ductile α-Ag S thin films and fabrication of all-inorganic, self-powered, and stretchable memory devices, is reported. Read More

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The Parameters Identification of High-Temperature Constitutive Model Based on Inverse Optimization Method and 3D Processing Map of Cr8 Alloy Steel.

Materials (Basel) 2021 Apr 26;14(9). Epub 2021 Apr 26.

Faculty of Mechanical, Jeju National University, Jeju Island 63243, Korea.

As a novel kind of cold roller steel, Cr8 alloy steel has the characteristics of high hardness, high wear resistance and good toughness, which can effectively prolong the service life of the roller that is an important part of the steel rolling mill. How to accurately define the constitutive model parameters of metal materials is the major problem, because it seriously affects the accuracy of numerical simulation results of the roller hot forming process. In the study of Cr8 alloy steel's thermal deformation behavior of the present paper, the high temperature compression test was done on a Gleebel-1500D thermal/force simulation testing machine. Read More

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Tensile Deformation and Fracture Behavior of Nickel-Based Superalloy DZ951G.

Materials (Basel) 2021 Apr 27;14(9). Epub 2021 Apr 27.

Shi-Changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China.

DZ951G is a novel developed nickel-based directional solidified superalloy with an incipient high melting point and low density. Compared with DZ417G superalloy, DZ951G superalloy has a higher ultimate tensile strength. At intermediate temperatures, the plasticity and strength were both markedly improved, and an obviously anomalous yield behavior could be observed where the yield strength reached its maximum at 760 °C. Read More

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Coupled Thermomechanical Response Measurement of Deformation of Nickel-Based Superalloys Using Full-Field Digital Image Correlation and Infrared Thermography.

Materials (Basel) 2021 Apr 23;14(9). Epub 2021 Apr 23.

Department of Metal Working and Physical Metallurgy of Non-Ferrous Metals, Faculty of Non-Ferrous Metals, AGH-University of Science and Technology, al. Adama Mickiewicza 30, 30-059 Cracow, Poland.

The paper is devoted to highlighting the potential application of the quantitative imaging technique through results associated with work hardening, strain rate and heat generated during elastic and plastic deformation. The aim of the research presented in this article is to determine the relationship between deformation in the uniaxial tensile test of samples made of 1-mm-thick nickel-based superalloys and their change in temperature during deformation. The relationship between yield stress and the Taylor-Quinney coefficient and their change with the strain rate were determined. Read More

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Predictive Computational Model for Damage Behavior of Metal-Matrix Composites Emphasizing the Effect of Particle Size and Volume Fraction.

Materials (Basel) 2021 Apr 23;14(9). Epub 2021 Apr 23.

Department of Mechanical Design and Production Engineering, Faculty of Engineering, Zagazig University, Zagazig P.O. Box 44519, Egypt.

In this paper, an integrated numerical model is proposed to investigate the effects of particulate size and volume fraction on the deformation, damage, and failure behaviors of particulate-reinforced metal matrix composites (PRMMCs). In the framework of a random microstructure-based finite element modelling, the plastic deformation and ductile cracking of the matrix are, respectively, modelled using Johnson-Cook constitutive relation and Johnson-Cook ductile fracture model. The matrix-particle interface decohesion is simulated by employing the surface-based-cohesive zone method, while the particulate fracture is manipulated by the elastic-brittle cracking model, in which the damage evolution criterion depends on the fracture energy cracking criterion. Read More

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Wire-Feeding Laser Welding of Copper/Stainless Steel Using Different Filler Metals.

Materials (Basel) 2021 Apr 22;14(9). Epub 2021 Apr 22.

Key Laboratory of Automobile Materials, School of Materials Science and Engineering, Jilin University, 2699 Qianjin St., Changchun 130025, China.

Ni-based filler metal and Ni-Cu-based filler metal were used to obtain copper/stainless steel (Cu/SS) joints through wire-feeding laser welding. Along the SS/weld interface, there exist different grain sizes (from coarse columnar grains to fine equiaxed grains). The heat affected zone (HAZ) on the copper side consisted of two areas with different grain sizes and the size of the grain in the Cu-HAZ of the Ni-Cu-based filled joint was much smaller than that of the Ni-based filled joint. Read More

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Microstructure and Hot Deformation Behavior of the Mg-8 wt.% Sn-1.5 wt.% Al Alloy.

Materials (Basel) 2021 Apr 19;14(8). Epub 2021 Apr 19.

China United Test & Certification Co., Ltd., Beijing 101407, China.

Mg-Sn-Al alloy is a new type of heat-resistant magnesium alloy with great potential and the hot deformation process of this alloy is of great significance for its application. The microstructure, hot deformation behavior, textural evolution, and processing map of a Mg-8 wt.% Sn-1. Read More

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A High-Strain-Rate Superplasticity of the Al-Mg-Si-Zr-Sc Alloy with Ni Addition.

Materials (Basel) 2021 Apr 17;14(8). Epub 2021 Apr 17.

Department of Physical Metallurgy of Non-Ferrous Metals, National University of Sciences and Technology ''MISIS", 4 Leninskiy ave. 4, 119049 Moscow, Russia.

The current study analyzed the effect of Ni content on the microstructure and superplastic deformation behavior of the Al-Mg-Si-Cu-based alloy doped with small additions of Sc and Zr. The superplasticity was observed in the studied alloys due to a bimodal particle size distribution. The coarse particles of eutectic origin AlNi and MgSi phases with a total volume fraction of 4. Read More

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Application of the Strain Compensation Model and Processing Maps for Description of Hot Deformation Behavior of Metastable β Titanium Alloy.

Materials (Basel) 2021 Apr 17;14(8). Epub 2021 Apr 17.

Faculty of Metals Engineering and Industrial Computer Science, AGH University of Science and Technology, Av. Mickiewicza 30, 30-059 Krakow, Poland.

The flow behavior of metastable β titanium alloy was investigated basing on isothermal hot compression tests performed on Gleeble 3800 thermomechanical simulator at near and above β transus temperatures. The flow stress curves were obtained for deformation temperature range of 800-1100 °C and strain rate range of 0.01-100 s. Read More

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An Acoustic Emission Method for Assessing the Degree of Degradation of Mechanical Properties and Residual Life of Metal Structures under Complex Dynamic Deformation Stresses.

Materials (Basel) 2021 Apr 21;14(9). Epub 2021 Apr 21.

Department of Energetics, Electrical Engineering and Physics, Kherson National Technical University, 73008 Kherson, Ukraine.

An acoustic emission method for assessing the degree of degradation of mechanical properties under conditions of complex dynamic deformation stresses is proposed. It has been shown that changing the operating conditions of metal structures, peak loads, external collisions, and thermally changing loads, which cannot be taken into account, leads to uncertainty and unpredictable structural changes in the material. This in turn makes it difficult to identify the state of the structure material to ensure trouble-free operation of the equipment. Read More

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Pop-In Phenomenon as a Fundamental Plasticity Probed by Nanoindentation Technique.

Materials (Basel) 2021 Apr 9;14(8). Epub 2021 Apr 9.

Research Center for Structural Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, Japan.

The attractive strain burst phenomenon, so-called "pop-in", during indentation-induced deformation at a very small scale is discussed as a fundamental deformation behavior in various materials. The nanoindentation technique can probe a mechanical response to a very low applied load, and the behavior can be mechanically and physically analyzed. The pop-in phenomenon can be understood as incipient plasticity under an indentation load, and dislocation nucleation at a small volume is a major mechanism for the event. Read More

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In Situ Computed Tomography-Analysis of a Single-Lap Shear Test with Clinch Points.

Materials (Basel) 2021 Apr 9;14(8). Epub 2021 Apr 9.

Institute of Lightweight Engineering and Polymer Technology (ILK), Technische Universität Dresden, 01069 Dresden, Germany.

As lightweight design gains more and more attention, time and cost-efficient joining methods such as clinching are becoming more popular. A clinch point's quality is usually determined by ex situ destructive analyses such as microsectioning. However, these methods do not yield the detection of phenomena occurring during loading such as elastic deformations and cracks that close after unloading. Read More

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Structural Reinforcement Effect of a Flexible Strain Sensor Integrated with Pneumatic Balloon Actuators for Soft Microrobot Fingers.

Micromachines (Basel) 2021 Apr 2;12(4). Epub 2021 Apr 2.

Graduate Course of Science and Engineering, Ritsumeikan University, Kusatsu 525-8577, Japan.

Motion capture of a robot and tactile sensing for a robot require sensors. Strain sensors are used to detect bending deformation of the robot finger and to sense the force from an object. It is important to introduce sensors in effective combination with actuators without affecting the original performance of the robot. Read More

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Effect of Wave Process of Plastic Deformation at Forging on the Fatigue Fracture Mechanism of Titanium Compressor Disks of Gas Turbine Engine.

Materials (Basel) 2021 Apr 8;14(8). Epub 2021 Apr 8.

Institute of Computer Aided Design, 2nd Brestskaya street 19/18, 123056 Moscow, Russia.

The low-cycle fatigue behavior of the VT3-1 titanium alloy (Ti-6Al-3Mo-2Cr alloy) under loading with a triangular and trapezoidal shape of cycle waveform was studied on round specimens prepared from forged compressor disks of a gas turbine engine. The filament type structure after forging has alternating filaments with the ductile and quasi-brittle state of the metal as a result of the wave process of plastic deformation during the metal forging process. The crack propagation, regardless of the cyclic waveform shape, occurs by the crack meso-tunneling mechanism: initially, the cracks propagate along the filaments by a quasi-brittle mechanism with the formation of a facetted pattern relief on the fracture surface reflecting the two-phase structure of the titanium alloy, and then, the bridge between the meso-tunnels is fractured with the formation of fatigue striations. Read More

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Microstructure Development and Properties of the Two-Component Melt-Spun NiFeCuPB Alloy at Elevated Temperatures.

Materials (Basel) 2021 Apr 1;14(7). Epub 2021 Apr 1.

Faculty of Metals Engineering and Industrial Computer Science, AGH University of Science and Technology, Al. A. Mickiewicza 30, 30-059 Kraków, Poland.

The aim of this work was to investigate the features of microstructure, phase composition, mechanical properties, and thermal stability of the two-component melt-spun Ni55Fe20Cu5P10B10 alloy. The development of the microstructure after heating to elevated temperatures was studied using scanning electron microscope and in situ high temperature X-ray diffraction. The high-temperature behavior of the two-component melt-spun Ni55Fe20Cu5P10B10 alloy and Ni40Fe40B20, Ni70Cu10P20, and Ni55Fe20Cu5P10B10 alloys melt-spun from single-chamber crucible was investigated using differential scanning calorymetry at different heating rates and by dynamic mechanical thermal analysis. Read More

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Microstructure, Hot Deformation Behavior, and Recrystallization Behavior of Zn-1Fe-1Mg Alloy under Isothermal Compression.

Materials (Basel) 2021 Apr 1;14(7). Epub 2021 Apr 1.

State Key Laboratory of Nonferrous Metals and Processes, GRIMAT Engineering Institute Co., Ltd., Beijing 100088, China.

Nowadays, wrought zinc-based biodegradable alloys are favored by researchers, due to their excellent mechanical properties and suitable degradation rates. However, there are few research studies on their thermal deformation behavior at present. This study took Zn-1Fe-1Mg and explored its microstructural change, deformation, recrystallization behavior and processing map by means of the thermal simulation experiment, at temperatures ranging from 235 °C to 340 °C and strain rates ranging from 10 s to 10 s. Read More

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Highly Strain-Tunable Interlayer Excitons in MoS/WSe Heterobilayers.

Nano Lett 2021 Apr 29. Epub 2021 Apr 29.

Department of Applied Physics and Materials Science, California Institute of Technology, Pasadena, California 91125, United States.

Interlayer excitons in heterobilayers of transition-metal dichalcogenides (TMDCs) have generated enormous interest due to their permanent vertical dipole moments and long lifetimes. However, the effects of mechanical strain on the optoelectronic properties of interlayer excitons in heterobilayers remain relatively uncharacterized. Here, we experimentally demonstrate strain tuning of Γ- interlayer excitons in molybdenum disulfide and tungsten diselenide (MoS/WSe) wrinkled heterobilayers and obtain a deformation potential constant of ∼107 meV/% uniaxial strain, which is approximately twice that of the intralayer excitons in the constituent monolayers. Read More

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[Comparative study on the mechanical properties of lower limb arterial stents under various deformation modes].

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 2021 Apr;38(2):303-309

College of Mechanical Engineering, Inner Mongolia University of Technology, Hohhot 010051, P.R.China.

Lower extremity movement is a complex and large range of limb movement. Arterial stents implanted in lower extremity are prone to complex mechanical deformation, so the stent is required to have high comprehensive mechanical properties. In order to evaluate the mechanical property of different stents, in this paper, finite element method was used to simulate and compare the mechanical properties of six nitinol stents (Absolute Pro, Complete SE, Lifestent, Protégé EverFlex, Pulsar-35 and New) under different deformation modes, such as radial compression, axial compression/tension, bending and torsion, and the radial support performance of the stents was verified by experiments. Read More

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Fracture Resistance of Zirconia, Polyetheretherketone, and Polyetherketoneketone Implant Abutments After Aging.

Int J Oral Maxillofac Implants 2021 Mar-Apr;36(2):332-340

Purpose: This study aimed to assess the fracture resistance of zirconia (Zr), reinforced polyetheretherketone (PEEK), and polyetherketoneketone (PEKK) implant abutments restored with glass-ceramic crowns after thermomechanical aging.

Materials And Methods: Zr, reinforced PEEK, and PEKK titanium base abutments were divided into three groups (n = 10). CAD/CAM maxillary central incisor crowns were fabricated using monolithic lithium disilicate and luted to the abutments using resin cement. Read More

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MR to ultrasound image registration with segmentation-based learning for HDR prostate brachytherapy.

Med Phys 2021 Apr 27. Epub 2021 Apr 27.

Department of Radiation Oncology, Stanford University, Stanford, 94305, USA.

Purpose: Propagation of contours from high-quality magnetic resonance (MR) images to treatment planning ultrasound (US) images with severe needle artifacts is a challenging task, which can greatly aid the organ contouring in high dose rate (HDR) prostate brachytherapy. In this study, a deep learning approach was developed to automatize this registration procedure for HDR brachytherapy practice.

Methods: Because of the lack of training labels and difficulty of accurate registration from inferior image quality, a new segmentation-based registration framework was proposed for this multi-modality image registration problem. Read More

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Deformation mechanisms of Inconel-718 at the nanoscale by molecular dynamics.

Phys Chem Chem Phys 2021 May;23(17):10650-10661

Department of Mechanical Engineering, Bangladesh University of Engineering and Technology, Dhaka-1000, Bangladesh and Theoretical and Applied Mechanics, Northwestern University, Evanston, Illinois, USA.

Ni-based super alloy Inconel-718 is ubiquitous in metal 3D printing where a high cooling rate and thermal gradient are present. These manufacturing conditions are conducive to high initial dislocation density and porosity or voids in the material. This work proposes a molecular dynamics (MD) analysis method that can examine the role of dislocations, cooling rates, voids, and their interactions governing the material properties and failure mechanisms in Inconel-718 using the Embedded Atom Method (EAM) potential. Read More

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Dislocations in ceramic electrolytes for solid-state Li batteries.

Sci Rep 2021 Apr 26;11(1):8949. Epub 2021 Apr 26.

Department of Material Science and Engineering, NTNU Norwegian University of Science and Technology, Trondheim, Norway.

High power solid-state Li batteries (SSLB) are hindered by the formation of dendrite-like structures at high current rates. Hence, new design principles are needed to overcome this limitation. By introducing dislocations, we aim to tailor mechanical properties in order to withstand the mechanical stress leading to Li penetration and resulting in a short circuit by a crack-opening mechanism. Read More

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Gold nanostar as an ultrasensitive colorimetric probe for picomolar detection of lead ion.

Anal Chim Acta 2021 May 12;1160:338380. Epub 2021 Mar 12.

Department of Pharmacy, University of South China, Henyang, 421001, China.

The sensitivity for analytes of interest is vital for environment protection and food safety. Here, we propose an extremely sensitive assay toward Pb by using gold nanostars (GNSs) as probes based on the catalytic activity of Pb on etching gold atoms after being reduced in the presence of 2-mercaptoethanol (2-ME) and sodium thiosulfate. GNSs were prepared by using 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid as both the reducing and capping agents, enabling high stability and sensitivity for quantitation of Pb. Read More

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A strain rate dependent thermo-elasto-plastic constitutive model for crystalline metallic materials.

Sci Rep 2021 Apr 23;11(1):8859. Epub 2021 Apr 23.

State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing, 100190, China.

The strain rate and temperature effects on the deformation behavior of crystalline metal materials have always been a research hotspot. In this paper, a strain rate dependent thermo-elasto-plastic constitutive model was established to investigate the deformation behavior of crystalline metal materials. Firstly, the deformation gradient was re-decomposed into three parts: thermal part, elastic part and plastic part. Read More

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Reducing Metal/Graphene Contact Resistance via N, N-Dimethylacetamide-Assisted Clean Fabrication Process.

Nanotechnology 2021 Apr 21. Epub 2021 Apr 21.

Institute of Microelectronics Chinese Academy of Sciences, Beijing, CHINA.

Contact resistance (R) is of great importance for radio frequency (RF) applications of graphene, especially graphene field effect transistors (FETs) with short channel. FETs and transmission line model (TLM) test structures based on chemical vapor deposition grown graphene are fabricated. The effects of employing traditional lithography solvent (Acetone) and strong solvents for photo resist, such as N, N-Dimethylacetamide (ZDMAC) and N-Methyl pyrrolidone (NMP), are systematically investigated. Read More

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Negative linear compressibility in nanoporous metal-organic frameworks rationalized by the empty channel structural mechanism.

Phys Chem Chem Phys 2021 Apr 25;23(14):8508-8524. Epub 2021 Mar 25.

Instituto de Estructura de la Materia (IEM-CSIC), C/Serrano, 113 - 28006 Madrid, Spain.

Zinc squarate tetrahydrate (ZnCO·4HO) and titanium oxalate trioxide dihydrate (Ti(CO)O·2HO) are nanoporous metal-organic frameworks possessing empty channels in their crystal structures. The crystal structures and mechanical properties of these materials are studied using first principles solid-state methods based on Density Functional Theory. The results show that they exhibit the negative linear compressibility (NLC) and negative Poisson's ratio (NPR) phenomena. Read More

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A correlation between grain boundary character and deformation twin nucleation mechanism in coarse-grained high-Mn austenitic steel.

Sci Rep 2021 Apr 19;11(1):8468. Epub 2021 Apr 19.

Department of Materials Science and Engineering, Virginia Tech, Blacksburg, VA, 24061, USA.

In polycrystalline materials, grain boundaries are known to be a critical microstructural component controlling material's mechanical properties, and their characters such as misorientation and crystallographic boundary planes would also influence the dislocation dynamics. Nevertheless, many of generally used mechanistic models for deformation twin nucleation in fcc metal do not take considerable care of the role of grain boundary characters. Here, we experimentally reveal that deformation twin nucleation occurs at an annealing twin (Σ3{111}) boundary in a high-Mn austenitic steel when dislocation pile-up at Σ3{111} boundary produced a local stress exceeding the twining stress, while no obvious local stress concentration was required at relatively high-energy grain boundaries such as Σ21 or Σ31. Read More

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Study on tribological performance of groove-textured bioimplants.

J Mech Behav Biomed Mater 2021 Apr 14;119:104514. Epub 2021 Apr 14.

Centre of Micro/Nano Manufacturing Technology (MNMT-Dublin), School of Mechanical & Materials Engineering, University College Dublin, Dublin 4, Ireland; State Key Laboratory of Precision Measuring Technology and Instruments, Laboratory of Micro/Nano Manufacturing Technology (MNMT), Tianjin University, Tianjin 300072, China. Electronic address:

Surface texturing is an effective approach to improve the tribological performance of artificial joints. In this paper, the frictional performance of Ultra-High-Molecular-Weight-Polyethylene and Cobalt-Chromium-Molybdenum material combination with micro grooves fabricated on the metal bearings is studied. The results show that grooves with width of 500 μm, depth of 4. Read More

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