Effect of High Temperature Exposure on the Mechanical Properties of Self-Hardening Al-Based Alloy

2016 ◽  
Vol 879 ◽  
pp. 1489-1494
Author(s):  
Ildiko Peter ◽  
Christian Castella ◽  
Silvia Lombardo ◽  
Mario Rosso
Keyword(s):  
Room Temperature ◽  
Microstructural Analysis ◽  
Cost Effective ◽  
Structural Components ◽  
Grain Refiner ◽  
Casting Technique ◽  
Wide Range ◽  
Toughness Evaluation ◽  
Temperature Exposure ◽  
Mould Casting

Cost-effective, modified, self-hardening Al-based alloy is proposed for automotive and aircraft industries. AlZn10Si8Mg is produced by permanent mould casting technique, and the obtained material is re-melted to refine and modify its microstructure and to develop a mechanically more efficient alloy. Ti as grain refiner, in form of TiB, and modifier, in forms of AlSr, were added to the basic alloy composition. Microstructural analysis and impact toughness evaluation were performed at room temperature and up to 180°C. The results obtained confirm that the proposed alloy reveal good properties in the considered temperature range, and demonstrate their applicability for structural components development in the aforementioned areas and in a wide range of temperature.

Tensile Properties at High and Low Temperatures and at Room Temperature after High-Temperature Exposure

2004 ◽  
pp. 211-242
Keyword(s):  
High Temperatures ◽  
Room Temperature ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Data Set ◽  
Casting Alloys ◽  
Subzero Temperatures ◽  
Wide Range ◽  
Temperature Exposure ◽  
High And Low Temperatures

Abstract This data set contains the results of uniaxial tensile tests of a wide range of aluminum casting alloys conducted at high temperatures from 100 to 370 deg C, subzero temperatures from -269 to -28 deg C, and room temperature after holding at high temperatures from 100 to 370 deg C. In most cases, tests were made of several lots of material of each alloy and temper. The results for the several lots were then analyzed together graphically and statistically, and the averages were normalized to the room-temperature typical values. For some alloys, "representative" values (raw data) rather than typical values are provided.

Magnetic Properties of Some Hydrated Transition Metal Oxide and Hydroxide Nanoparticles Synthesized in Different Media

2010 ◽  
Vol 123-125 ◽  
pp. 727-730 ◽  
Author(s):  
Abdulaziz A. Bagabas ◽  
Khalil A. Ziq ◽  
Ahmad F. Salem ◽  
Emad S. Addurihem
Keyword(s):  
Particle Size ◽  
Transition Metal ◽  
Room Temperature ◽  
Permanent Magnets ◽  
Cost Effective ◽  
Precipitation Method ◽  
Energy Product ◽  
Wide Range ◽  
Precipitation Medium ◽  
And Performance

Nanoscale particle size of metal oxides and hydroxides showed enhanced various physical properties and performance. We established a simple, cost-effective, room-temperature (RT) precipitation method for the preparation of the magnetic, first-raw transition metal (TM) hydrated oxide and hydroxide nanoparticles. This method is based on the use of the TM nitrate, as the metal source, and cyclohexylamine (CHA), as a precipitating agent, either in the water (H2O) or ethanol (EtOH) medium. We found that the precipitation medium and the identity of precipitated TM strongly affect the morphology, particle size, and magnetism of the product. The morphology varies from spherical, to rectangular, to rod shape; while the size varies in the range of 5-30 nm. All samples showed paramagnetic behavior with Curie temperatures span over a wide range (20-150K). Huge hysteresis looses has been observed for manganese (Mn) sample, prepared in H2O. The coercively (Hc) at 4.2K for this sample is about 1.5T, which is comparable to the strongest permanent magnets (Nd-based magnets) available at room temperature. The energy product (Hc*MR) is about 4.5*105 (emu/g)Oe.

scholarly journals Highly Sensitive Hydrogen Sensor Based on Palladium-Coated Tapered Optical Fiber at Room Temperature

2020 ◽  
Vol 2 (1) ◽  
pp. 8
Author(s):  
Mohammed Majeed Alkhabet ◽  
Saad Hayatu Girei ◽  
Suriati Paiman ◽  
Norhana Arsad ◽  
Mohd Adzir Mahdi ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Room Temperature ◽  
Light Propagation ◽  
Cost Effective ◽  
Hydrogen Sensor ◽  
X Ray ◽  
Multimode Optical Fiber ◽  
Casting Technique ◽  
H2 Sensor ◽  
Tapered Optical Fiber

This paper describes the application of a palladium (Pd)-coated tapered optical fiber in order to develop a hydrogen (H2) sensor. A transducing channel was fabricated with multimode optical fiber (MMF) with cladding and core diameters of 125 µm and 62.5 µm, respectively, in order to enhance the evanescent field of light propagation through the fiber. The multimode optical fiber was tapered from a cladding diameter of 125 µm to a waist diameter of 20 µm, waist-length of 10 mm, and down taper and up of 5 mm, and coated with Pd using the drop-casting technique. In order to establish the palladium’s properties, various characterization techniques were applied, such as Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray (EDX), and X-ray Diffraction (XRD). The developed palladium sensor functioned reproducibly at a gas concentration of 0.125% to 1.00% H2 at room temperature in the synthetic air. In this case, the response and recovery times were 50 and 200 s, respectively. Furthermore, this study demonstrated that the production of a dependable, effective, and reproducible H2 sensor by applying a basic, cost-effective method is possible.

scholarly journals Structural and optical properties of a revived Pb0.5Ba1.5BiVO6 perovskite oxide

2019 ◽  
Vol 09 (01) ◽  
pp. 1950004 ◽  
Author(s):  
R. K. Parida ◽  
D. K. Pattanayak ◽  
Bhagyashree Mohanty ◽  
Nimai C. Nayak ◽  
B. N. Parida
Keyword(s):  
Perovskite Structure ◽  
Room Temperature ◽  
Microstructural Analysis ◽  
Compositional Analysis ◽  
Rhombohedral Phase ◽  
Double Perovskite ◽  
Xrd Analysis ◽  
Perovskite Oxide ◽  
Dielectric Study ◽  
Wide Range

The polycrystalline ceramic Pb[Formula: see text]Ba[Formula: see text]BiVO6 manifesting the complex double perovskite structure was tailored by the conventional solid state route at a moderate temperature. Qualitative phase analysis and formation of the ceramic were affirmed by XRD analysis. The X-ray powder diffraction pattern of the compound explored at room temperature affirms the single phase formation with double perovskite structure exhibiting rhombohedral phase. Microstructural analysis of the studied compound procured from the Scanning Electron Microscope (SEM) validates the formation of dense microstructures and nonuniformly distributed grains with minimal voids. Compositional analysis was shaped through the Electron Diffraction Spectroscopy (EDS) confirming the absence of contamination of any other metals apart from the mentioned ones. Dielectric (Cr and [Formula: see text]) parameters of the compound were studied using the LCR analyzer at different temperatures and wide range of frequencies. The polarization and dielectric study affirms the presence of ferroelectricity in the material with transition temperature much above the room temperature. The tangent dielectric loss of this sample being almost minimal at room temperature attributes it to find applications in different grounds of electronics. Optical equities of the ceramic were further analyzed by the RAMAN, FTIR, UV–Vis and Photoluminescence spectroscopy.

Magnetic Properties of Fe-Nb-B-Re (Re=Y, Gd) Bulk Nanocrystalline Alloys

2011 ◽  
Vol 170 ◽  
pp. 114-117 ◽  
Author(s):  
Artur Chrobak ◽  
G. Haneczok ◽  
Grażyna Chełkowska ◽  
Anna Bajorek ◽  
Jerzy Kansy ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Room Temperature ◽  
Preparation Method ◽  
Nanocrystalline Alloys ◽  
Squid Magnetometer ◽  
Casting Technique ◽  
Magnetic Hardening ◽  
Bulk Nanocrystalline ◽  
Mould Casting ◽  
Magnetic Balance

Magnetic properties of the Fe76.2Nb5.7B13.3Gd4.8, Fe69.6Nb5.2B12.2Gd13, Fe76.2Nb5.7B13.3Y4.8, Fe69.6Nb5.2B12.2Y13 bulk nanocrystalline alloys (mould casting technique) are presented and discussed. Measurements were carried out by the means of SQUID magnetometer (temperature range 2 K – 400 K, field up to 7 T) and magnetic balance (temperatures up to 1100 K). Microstructure was studied by the Mössbauer spectroscopy at room temperature. It was shown that the samples are nonocrystalline with α-Fe and different Fe-B, Y/Gd-Fe or Y/Gd-Fe-B compounds. The preparation method as well as the Gd addition causes a magnetic hardening of the studied alloys.

Effect of 1-Ethyl-3-Methylimidazolium Nitrate on the Electrical Properties of Starch/Chitosan Blend Polymer Electrolyte

2016 ◽  
Vol 846 ◽  
pp. 510-516 ◽  
Author(s):  
Azwani Sofia Ahmad Khiar ◽  
M.R.S. Anuar ◽  
M.A. Md Parid
Keyword(s):  
Polymer Electrolyte ◽  
Solid Polymer Electrolyte ◽  
Room Temperature ◽  
Liquid Electrolyte ◽  
Solid Polymer ◽  
Casting Technique ◽  
Wide Range ◽  
Solution Casting Technique ◽  
Blend Polymer Electrolyte ◽  
Blend Polymer

Solid polymer electrolyte (SPE) can be viewed as an alternative of conventional liquid electrolyte since it is easier to handle. Previous Solid polymer electrolyte (SPE) can be viewed as an alternative of conventional liquid electrolyte since it is easier to handle. In the present work, starch/chitosan-ammonium nitrate (NH4NO3) SPE has been prepared by solution casting technique. Different amount of 1-ethyl-3-methylimidazolium nitrate ([EMIM][NO3]) was added to the sample. Ionic conductivity analysis was conducted over a wide range of frequency between 50 Hz-1 MHz using impedance spectroscopy to evaluate the dielectric properties and conductivity of the sample.Sample with 15 wt% of [EMIM][NO3] has shown the highest conductivity of 7.36 x 10-5 S cm-1 at room temperature. Complex permittivity for real (εr), imaginary (εi) and electrical modulus for real (Mr) and imaginary (Mi) part was determined and plotted.

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

Evaluation of 99mTc-Label led Vitamin K4 as an Agent for Testicular Imaging

1991 ◽  
Vol 30 (01) ◽  
pp. 35-39 ◽  
Author(s):  
H. S. Durak ◽  
M. Kitapgi ◽  
B. E. Caner ◽  
R. Senekowitsch ◽  
M. T. Ercan
Keyword(s):  
Soft Tissue ◽  
Room Temperature ◽  
Normal Subjects ◽  
Left Testis ◽  
Wide Range ◽  
Activity Ratios ◽  
The Right ◽  
Radioactivity Levels

Vitamin K4 was labelled with 99mTc with an efficiency higher than 97%. The compound was stable up to 24 h at room temperature, and its biodistribution in NMRI mice indicated its in vivo stability. Blood radioactivity levels were high over a wide range. 10% of the injected activity remained in blood after 24 h. Excretion was mostly via kidneys. Only the liver and kidneys concentrated appreciable amounts of radioactivity. Testis/soft tissue ratios were 1.4 and 1.57 at 6 and 24 h, respectively. Testis/blood ratios were lower than 1. In vitro studies with mouse blood indicated that 33.9 ±9.6% of the radioactivity was associated with RBCs; it was washed out almost completely with saline. Protein binding was 28.7 ±6.3% as determined by TCA precipitation. Blood clearance of 99mTc-l<4 in normal subjects showed a slow decrease of radioactivity, reaching a plateau after 16 h at 20% of the injected activity. In scintigraphic images in men the testes could be well visualized. The right/left testis ratio was 1.08 ±0.13. Testis/soft tissue and testis/blood activity ratios were highest at 3 h. These ratios were higher than those obtained with pertechnetate at 20 min post injection.99mTc-l<4 appears to be a promising radiopharmaceutical for the scintigraphic visualization of testes.

2D Color-Intensity Representation of Ultrasonic Thickness Gauge Measurements

2020 ◽  
pp. 1192-1198
Author(s):  
M.S. Mohammad ◽  
Tibebe Tesfaye ◽  
Kim Ki-Seong
Keyword(s):  
Cost Effective ◽  
The Other ◽  
Thickness Gauge ◽  
Color Intensity ◽  
Digital Readout ◽  
Flat Surfaces ◽  
Video Cameras ◽  
Wide Range ◽  
Cost Effective Alternative ◽  
Ultrasonic Thickness

Ultrasonic thickness gauges are easy to operate and reliable, and can be used to measure a wide range of thicknesses and inspect all engineering materials. Supplementing the simple ultrasonic thickness gauges that present results in either a digital readout or as an A-scan with systems that enable correlating the measured values to their positions on the inspected surface to produce a two-dimensional (2D) thickness representation can extend their benefits and provide a cost-effective alternative to expensive advanced C-scan machines. In previous work, the authors introduced a system for the positioning and mapping of the values measured by the ultrasonic thickness gauges and flaw detectors (Tesfaye et al. 2019). The system is an alternative to the systems that use mechanical scanners, encoders, and sophisticated UT machines. It used a camera to record the probe’s movement and a projected laser grid obtained by a laser pattern generator to locate the probe on the inspected surface. In this paper, a novel system is proposed to be applied to flat surfaces, in addition to overcoming the other limitations posed due to the use of the laser projection. The proposed system uses two video cameras, one to monitor the probe’s movement on the inspected surface and the other to capture the corresponding digital readout of the thickness gauge. The acquired images of the probe’s position and thickness gauge readout are processed to plot the measured data in a 2D color-coded map. The system is meant to be simpler and more effective than the previous development.

The Future of Plasma-Based Surface Engineering Techniques in Tribology (Keynote)

2005 ◽  
Author(s):  
Allan Matthews ◽  
Adrian Leyland
Keyword(s):  
Surface Engineering ◽  
Performance Enhancement ◽  
Bulk Material ◽  
Cost Savings ◽  
Cost Effective ◽  
Ceramic Coatings ◽  
Performance Improvements ◽  
Treatment Techniques ◽  
Wide Range ◽  
Macro Scale

Over the past twenty years or so, there have been major steps forward both in the understanding of tribological mechanisms and in the development of new coating and treatment techniques to better “engineer” surfaces to achieve reductions in wear and friction. Particularly in the coatings tribology field, improved techniques and theories which enable us to study and understand the mechanisms occurring at the “nano”, “micro” and “macro” scale have allowed considerable progress to be made in (for example) understanding contact mechanisms and the influence of “third bodies” [1–5]. Over the same period, we have seen the emergence of the discipline which we now call “Surface Engineering”, by which, ideally, a bulk material (the ‘substrate’) and a coating are combined in a way that provides a cost-effective performance enhancement of which neither would be capable without the presence of the other. It is probably fair to say that the emergence and recognition of Surface Engineering as a field in its own right has been driven largely by the availability of “plasma”-based coating and treatment processes, which can provide surface properties which were previously unachievable. In particular, plasma-assisted (PA) physical vapour deposition (PVD) techniques, allowing wear-resistant ceramic thin films such as titanium nitride (TiN) to be deposited on a wide range of industrial tooling, gave a step-change in industrial productivity and manufactured product quality, and caught the attention of engineers due to the remarkable cost savings and performance improvements obtained. Subsequently, so-called 2nd- and 3rd-generation ceramic coatings (with multilayered or nanocomposite structures) have recently been developed [6–9], to further extend tool performance — the objective typically being to increase coating hardness further, or extend hardness capabilities to higher temperatures.

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