scholarly journals Effect of Compound Fields of Ultrasonic Vibration and Applied Pressure on the 3D Microstructure and Tensile Properties of Recycled Al-Cu-Mn-Fe-Si Alloys

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3904 ◽  
Author(s):  
Yuliang Zhao ◽  
Bo Lin ◽  
Dongfu Song ◽  
Donghai Zheng ◽  
Zhenzhong Sun ◽  
...  
Keyword(s):  
Tensile Properties ◽  
Ultrasonic Vibration ◽  
Acoustic Streaming ◽  
Applied Pressure ◽  
Three Dimensional ◽  
Pouring Temperature ◽  
Microstructural Refinement ◽  
3D Microstructure ◽  
Dendrite Fragmentation ◽  
Solution Strengthening

The effect of compound fields of ultrasonic vibration and applied pressure (UV+AP) on three-dimensional (3D) microstructure and tensile properties of recycled Al-Cu-Mn-Fe-Si alloys was systematically studied using conventional two-dimensional (2D) microscopy, synchrotron X-ray tomography, and tensile test. The properties of UV+AP treated alloys with the pouring temperature of 740, 710 and 680 °C were compared when those alloys achieved after gravity casting. After UV+AP treatment, the alloy with pouring temperature of 710 °C show the smallest grain size. Also, the sizes of Fe-rich phases and Al2Cu are greatly reduced and their 3D morphologies are compacted. The mechanical properties of UV+AP treated alloys are relatively higher than those measured for gravity cast equivalents. This improvement can be explained by the synergistic effect of acoustic cavitation, acoustic streaming, and force-feeding, which resulted in the dendrite fragmentation, uniform solute distribution, and microstructural refinement. The Orowan strengthening and solution strengthening were identified as the main strengthening mechanisms.

Design and calibration of an IVEM for general 3-dimensional imaging of non-diffracting materials

1992 ◽  
Vol 50 (2) ◽  
pp. 1040-1041
Author(s):  
Neil Rowlands ◽  
Jeff Price ◽  
Michael Kersker ◽  
Seichi Suzuki ◽  
Steve Young ◽  
...  
Keyword(s):  
3D Imaging ◽  
Tomographic Reconstruction ◽  
Three Dimensional ◽  
3 Dimensional ◽  
3D Microstructure ◽  
Image Translation ◽  
Digital Correlation ◽  
On Line ◽  
Mechanical Stage ◽  
Projection Angle

Three-dimensional (3D) microstructure visualization on the electron microscope requires that the sample be tilted to different positions to collect a series of projections. This tilting should be performed rapidly for on-line stereo viewing and precisely for off-line tomographic reconstruction. Usually a projection series is collected using mechanical stage tilt alone. The stereo pairs must be viewed off-line and the 60 to 120 tomographic projections must be aligned with fiduciary markers or digital correlation methods. The delay in viewing stereo pairs and the alignment problems in tomographic reconstruction could be eliminated or improved by tilting the beam if such tilt could be accomplished without image translation.A microscope capable of beam tilt with simultaneous image shift to eliminate tilt-induced translation has been investigated for 3D imaging of thick (1 μm) biologic specimens. By tilting the beam above and through the specimen and bringing it back below the specimen, a brightfield image with a projection angle corresponding to the beam tilt angle can be recorded (Fig. 1a).

OLIN ALLOY C5218

Alloy Digest ◽  
2004 ◽  
Vol 53 (6) ◽  
Keyword(s):  
Solid Solution ◽  
Physical Properties ◽  
Tensile Properties ◽  
Bend Strength ◽  
Bronze Alloy ◽  
Solid Solution Strengthening ◽  
Solution Strengthening

Abstract Olin Alloy C5218 is a phosphor bronze alloy given both dispersion- and solid-solution strengthening for applications in the automotive connector market. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength. Filing Code: CU-715. Producer or source: Olin Brass.

GRAIN REFINEMENT AND MICROSTRUCTURE EVOLUTION IN ALUMINUM A2618 ALLOY BY HIGH-PRESSURE TORSION

2016 ◽  
Vol 78 (6-9) ◽  
Author(s):  
Intan Fadhlina Mohamed ◽  
Seungwon Lee ◽  
Kaveh Edalati ◽  
Zenji Horita ◽  
Shahrum Abdullah ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
High Pressure ◽  
Grain Refinement ◽  
Room Temperature ◽  
Rotation Speed ◽  
High Pressure Torsion ◽  
Applied Pressure ◽  
Saturation Level ◽  
Microstructural Refinement ◽  
Average Grain Size

This work presents a study related to the grain refinement of an aluminum A2618 alloy achieved by High-Pressure Torsion (HPT) known as a process of Severe Plastic Deformation (SPD). The HPT is conducted on disks of the alloy under an applied pressure of 6 GPa for 1 and 5 turns with a rotation speed of 1 rpm at room temperature. The HPT processing leads to microstructural refinement with an average grain size of ~250 nm at a saturation level after 5 turns. Gradual increases in hardness are observed from the beginning of straining up to a saturation level. This study thus suggests that hardening due to grain refinement is attained by the HPT processing of the A2618 alloy at room temperature.

Stresses in Ultrasonically Assisted Turning

2006 ◽  
Vol 5-6 ◽  
pp. 351-358 ◽  
Author(s):  
N. Ahmed ◽  
A.V. Mitrofanov ◽  
Vladimir I. Babitsky ◽  
Vadim V. Silberschmidt
Keyword(s):  
Ultrasonic Vibration ◽  
Vibration Frequency ◽  
Cutting Forces ◽  
Plastic Material ◽  
Process Zone ◽  
Three Dimensional ◽  
Rate Sensitivity ◽  
High Strength ◽  
Material Model ◽  
Shear Stresses

Ultrasonically assisted turning (UAT) is a novel material-processing technology, where high frequency vibration (frequency f ≈ 20kHz, amplitude a ≈15μm) is superimposed on the movement of the cutting tool. Advantages of UAT have been demonstrated for a broad spectrum of applications. Compared to conventional turning (CT), this technique allows significant improvements in processing intractable materials, such as high-strength aerospace alloys, composites and ceramics. Superimposed ultrasonic vibration yields a noticeable decrease in cutting forces, as well as a superior surface finish. A vibro-impact interaction between the tool and workpiece in UAT in the process of continuous chip formation leads to a dynamically changing stress distribution in the process zone as compared to the quasistatic one in CT. The paper presents a three-dimensional, fully thermomechanically coupled computational model of UAT incorporating a non-linear elasto-plastic material model with strain-rate sensitivity and contact interaction with friction at the chip–tool interface. 3D stress distributions in the cutting region are analysed for a representative cycle of ultrasonic vibration. The dependence of various process parameters, such as shear stresses and cutting forces on vibration frequency and amplitude is also studied.

Microstructure and mechanical property of TiB reinforced Ti matrix composites fabricated by ultrasonic vibration-assisted laser engineered net shaping

2019 ◽  
Vol 25 (3) ◽  
pp. 581-591 ◽  
Author(s):  
Fuda Ning ◽  
Yingbin Hu ◽  
Weilong Cong
Keyword(s):  
Ultrasonic Vibration ◽  
Acoustic Streaming ◽  
Nonlinear Effects ◽  
Small Variation ◽  
Microstructural Characterization ◽  
Matrix Composites ◽  
Heterogeneous Distribution ◽  
Content Type ◽  
Laser Engineered Net Shaping ◽  
Net Shaping

Purpose The purpose of this paper is to identify if the implementation of ultrasonic vibration in laser engineered net shaping (LENS) process can help to reduce internal weaknesses such as porosity, coarse primary TiB whisker and heterogeneous distribution of TiB reinforcement in the LENS-fabricated TiB reinforced Ti matrix composites (TiB-TMC) parts. Design/methodology/approach An experimental investigation is performed to achieve the results for comparative studies under different fabrication conditions through quantitative data analysis. An approach of microstructural characterization and mechanical testing is conducted to obtain the output attributes. In addition, the theoretical analysis of the physics of ultrasonic vibration in the melting materials is presented to explain the influences of ultrasonic vibration on the microstructural evolution occurred in the part fabrication. Findings Because of the nonlinear effects of acoustic streaming and cavitation induced by ultrasonic vibration, porosity is significantly reduced and a relatively small variation of pore sizes is achieved. Ultrasonic vibration also causes the formation of smaller TiB whiskers that distribute along grain boundaries with a homogeneous dispersion. Additionally, a quasi-continuous network (QCN) microstructure is considerably finer than that produced by LENS process without ultrasonic vibration. The refinements of both reinforcing TiB whiskers and QCN microstructural grains further improve the microhardness of TiB-TMC parts. Originality/value The novel ultrasonic vibration-assisted (UV-A) LENS process of TiB-TMC is conducted in this work for the first time to improve the process performance and part quality.

scholarly journals Research on Cutting Force and Surface Integrity of TC18 Titanium Alloy by Longitudinal Ultrasonic Vibration Assisted Milling

2021 ◽  
Author(s):  
Weibo Xie ◽  
Xikui Wang ◽  
Erbo Liu ◽  
Jian Wang ◽  
Xiaobin Tang ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Cutting Force ◽  
Ultrasonic Vibration ◽  
Surface Integrity ◽  
Rotational Speed ◽  
Three Dimensional ◽  
Cutting Temperature ◽  
Surface Residual Stress ◽  
Deformation Layer ◽  
Vibration Milling

Abstract In order to study the influence of rotational speed and amplitude on the surface integrity, TC18 titanium alloy samples were milled by the process of conventional milling and longitudinal ultrasonic vibration assisted milling. The experimental data were obtained by dynamometer, thermometer, scanning electron microscope, X-ray diffractometer and three-dimensional surface topography instrument for observation and analysis. The results show that the rotational speed has a significant effect on the cutting force, cutting temperature, surface morphology and surface residual stress. Compared with ordinary milling, the surface micro-texture produced by ultrasonic vibration milling is more regular, , and with the increase of rotational speed, the influence of ultrasonic vibration on cutting force and cutting temperature decrease. There are adverse effects on surface roughness after ultrasonic vibration superposition. The influence of ultrasonic vibration on the surface residual compressive stress is also greatly reduced when the rotational speed is greater than 2400 rpm. In addition, a certain depth of plastic deformation layer can be formed under the surface of ultrasonic vibration machining, and the depth of deformation layer increases with the increase of vibration.

scholarly journals Knitting Technologies And Tensile Properties Of A Novel Curved Flat-Knitted Three-Dimensional Spacer Fabrics

2015 ◽  
Vol 15 (3) ◽  
pp. 191-197 ◽  
Author(s):  
Xiaoying Li ◽  
Gaoming Jiang ◽  
Xiaolin Nie ◽  
Pibo Ma ◽  
Zhe Gao
Keyword(s):  
Tensile Stress ◽  
Tensile Properties ◽  
Dimensional Stability ◽  
Three Dimensional ◽  
Tensile Tests ◽  
Weft Direction ◽  
Aramid Fibres ◽  
Spacer Fabric ◽  
Fabric Deformation ◽  
Spacer Fabrics

AbstractThis paper introduces a knitting technique for making innovative curved three-dimensional (3D) spacer fabrics by the computer flat-knitting machine. During manufacturing, a number of reinforcement yarns made of aramid fibres are inserted into 3D spacer fabrics along the weft direction to enhance the fabric tensile properties. Curved, flat-knitted 3D spacer fabrics with different angles (in the warp direction) were also developed. Tensile tests were carried out in the weft and warp directions for the two spacer fabrics (with and without reinforcement yarns), and their stress–strain curves were compared. The results showed that the reinforcement yarns can reduce the fabric deformation and improve tensile stress and dimensional stability of 3D spacer fabrics. This research can help the further study of 3D spacer fabric when applied to composites.

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