scholarly journals INFORMATION-MEASURING ELECTROMECHANICAL TRANSDUCERS FOR ASSESSING THE QUALITY OF THE SURFACE OF FERROMAGNETIC METAL ITEMS BY ULTRASONIC WAVES RAYLEIGH

2017 ◽  
Vol 2017 (2) ◽  
pp. 70-76 ◽  
Author(s):  
R.P. Migushchenko ◽  
◽  
G.M. Suchkov ◽  
O.N. Petrishchev ◽  
V.F. Bolyukh ◽  
...  
Keyword(s):  
Ultrasonic Waves ◽  
Ferromagnetic Metal ◽  
Information Measuring ◽  
Electromechanical Transducers

Development of a system using ultrasonic waves for assessing the quality of frying oil and salad oil during frying

2008 ◽  
Vol 123 (5) ◽  
pp. 3837-3837
Author(s):  
Driss Izbaim ◽  
Bouazza Faiz ◽  
Adil Hamine ◽  
Naima Taifi ◽  
Ali Moudden
Keyword(s):  
Ultrasonic Waves ◽  
Frying Oil

Laser Ultrasonic Inspection of Solder Bumps in Flip Chip Packages Using Virtual Package Device as Reference

2010 ◽  
Author(s):  
I. Charles Ume ◽  
Jie Gong ◽  
Razid Ahmad ◽  
Abel Valdes
Keyword(s):  
Time Domain ◽  
Flip Chip ◽  
Electronic Device ◽  
Ultrasonic Inspection ◽  
Reference Method ◽  
Ultrasonic Waves ◽  
Quality Analysis ◽  
Inspection System ◽  
Solder Bumps

Flip chip package is widely used in the electronic device manufacturing industry. The top side of a flip chip device is manufactured with solder bumps. The device is then flipped on its top so that the solder bumps can be bonded to a substrate, forming the mechanical and electrical connection between the device and substrate. As a result, the solder bumps are sandwiched between the silicon die and the substrate, making them no longer visible for usual inspection. A novel solder joint inspection system capable of evaluating the quality of the hidden solder bumps on a flip chip package has been developed using laser ultrasound techniques. The system pulses a laser onto the top surface of a chip package to generate ultrasonic waves in the package and excite structural vibrations which can then be measured using an interferometer. Since defective solder bumps cause changes in the transient vibration response of a tested sample, quality of the tested sample can be assessed by correlating its vibration responses to that of a known good device. A limitation of this implementation is the necessity of a known-good reference chip package, which typically involves expensive testing using alternate methods. In this paper, the development of a method capable of generating a virtual reference chip package is presented. This method, called Hybrid Reference Method, uses a statistical approach to find which packages in a sample set are most similar and then averages their time domain signals to generate a virtual chip package, known as the Hybrid Reference Package. The signals associated with Hybrid Reference Package are then correlated with the time domain signals obtained from the packages under inspection to obtain a quality signature. Finally, defective and non-defective chip packages are separated by estimating a beta distribution that fits the quality signature histogram of the inspected packages and then determining a cutoff threshold for an acceptable quality signature. This method was applied to two types of flip chip packages where no pre-established known-good reference package was available. The results of this quality analysis were validated by comparison with electrical test and X-ray results.

scholarly journals Non-linear methods based on ultrasonic waves to analyse disbonds in single lap joints

2017 ◽  
Vol 231 (16) ◽  
pp. 3066-3076 ◽  
Author(s):  
G Scarselli ◽  
F Ciampa ◽  
F Nicassio ◽  
M Meo
Keyword(s):  
Adhesive Layer ◽  
Lap Joints ◽  
Ultrasonic Waves ◽  
Destructive Testing ◽  
Linear Elastic ◽  
Single Lap Joints ◽  
Non Linear ◽  
Structural Responses ◽  
Non Destructive

Adhesive bonded lap joints are widely used in the aerospace field and non-destructive testing (NDT) techniques are critical in evaluating the quality of adhesion before and during use. Two types of bonded samples have been experimentally investigated in order to verify the reliability of non-linear elastic wave spectroscopy (NEWS) based on the use of ultrasound. Piezoelectric sensors have been attached to the samples and used as generators and receivers. Both the samples have shown non-linearities in their dynamic behaviour. Non-linear metrics have been applied to their structural responses over an assigned range of excitation frequencies based on higher order harmonic analysis in order to evaluate the degree of non-linearity of the samples. Possible interpretations of the experimental behaviour are provided in the paper based also on tomographic testing of the adhesive layer that showed the presence of microbubbles in the bond due to manufacturing process.

Superimposing Ultrasonic Waves on the Dies in Tube and Wire Drawing

2001 ◽  
Vol 123 (4) ◽  
pp. 517-523 ◽  
Author(s):  
Klaus Siegert ◽  
Jochen Ulmer
Keyword(s):  
Sliding Friction ◽  
Wire Drawing ◽  
Ultrasonic Waves ◽  
Forming Process ◽  
Vibration Direction ◽  
Tube Drawing ◽  
Forming Technology ◽  
The University ◽  
Main Influence

The forces during wire and tube drawing can be reduced by ultrasonically oscillating dies. It is a major problem of conventional wire and tube drawing to introduce high forces into the forming area. Compared to conventional wire and tube drawing, the forming process limits can be extended by superimposing ultrasonic waves due to decreasing drawing forces. Different techniques can be used to excite the die. One possibility is the variation of the vibration mode. In tube and wire drawing, the dies are usually excited longitudinally. If the vibration direction is parallel to the drawing direction, the main influence will be on the friction between workpiece and die. The Institute for Metal Forming Technology of the University of Stuttgart, Germany started a project to investigate the effect of ultrasonic waves on the tribology and on the formability of the workpiece. The objective of this investigation is to separate the ultrasonic effect on the surface from the volume effects. This paper shows that the reduction of the sliding friction between a longitudinal oscillating die and the workpiece can be explained by the so-called Sliding Friction Vector Effect (SFVE). A statistical evaluation of roughness-measurements makes it possible to show the effect of the ultrasonic vibration on the friction and gives an insight into the operation of the SFVE. The results are compared with wire and tube drawing experiments of copper and Ti-alloys. New tube- and wire-drawing experiments with longitudinally vibrating dies support the theoretical approach. The surface quality of the manufactured workpieces can be improved and the productivity increased.

scholarly journals Modernization of information-measuring systems for grain processing

2021 ◽  
Vol 247 ◽  
pp. 01010
Author(s):  
Vitaliy Fedotov ◽  
Sergey Solovykh
Keyword(s):  
Neural Networks ◽  
Computer Vision ◽  
Artificial Neural Networks ◽  
Grain Hardness ◽  
Wheat Grain ◽  
Measuring Systems ◽  
Information Measuring ◽  
Grain Processing ◽  
Artificial Neural

The paper discusses the basic operation principles of information-measuring systems for optimization wheat grain processing. The quality of grain processing products (cereals, flour, etc.) is influenced by both weather and climatic factors and grinding technologies. The modern development of information technologies makes it possible to modernize the existing information-measuring systems for grain processing and create new ones through the development of algorithms for analyzing the physical characteristics of the grain mass. During the study, test grinding of wheat grains of different varieties was carried out in a laboratory mill. To increase the yield of the finished product, digitalization of the selection of optimal grain separation modes was used. The obtained mathematical models allow predicting the quality of grain separation in separators of various types. The digitalization of the grain processing industry includes the use of artificial neural networks to analyze images of the grain mass using computer vision algorithms. It is promising to increase the information content of granulometric analysis using modern intelligent (information-measuring) systems. For the classification of wheat according to the milling properties, it is proposed to use the grain hardness. The studies used computer vision and artificial neural networks to find and organize the particles of grain grinding by geometric properties. The characteristics of the contours of the images of the grinding particles were taken into account. The values obtained by the developed information-measuring system were compared with that obtained using the Russian State Standard GOST methods. The error in assessing the grain hardness by the new method does not exceed 3.5%. The use of modern information tools allows improving the quality of wheat grain processing.

Investigation of Ultrasonic Effect on Morphology, Optical and Growth Properties of ZnO Quantum Dots

2017 ◽  
Vol 49 ◽  
pp. 10-17
Author(s):  
Elaheh Moghaddam ◽  
Amir Ali Youzbashi ◽  
Asghar Kazemzadeh
Keyword(s):  
Quantum Dots ◽  
Ostwald Ripening ◽  
Ultrasonic Waves ◽  
Synthetic Methods ◽  
Crystal Quality ◽  
Growth Stages ◽  
Two Samples ◽  
Zno Quantum Dots ◽  
Diffraction Patterns

Recent advances in nanomaterials have been led by new synthetic methods that provide control over size, morphology and crystal quality of materials. The present study is tried to discuss the effect of ultrasonic waves on characteristics of ZnO quantum dots by study of UV absorption, photoluminescence spectroscopy, X ray diffraction patterns, transmission electron microscopy and growth stages of two samples prepared by sonochemical and conventional methods. The results demonstrated that the quantum dots synthesized under ultrasonic waves were of smaller size with more narrow size distribution. Also, improvement of their crystal quality was inferred from investigation of visible emission intensity. The use of ultrasonic waves caused the phase purity of nanocrystals obtained by complete conversion of precursors into ZnO. Further, the study of their growth stages indicated that the rapid nucleation and nucleation growth were followed by Ostwald ripening process which improve the crystal properties. The better crystal quality of ultrasonic prepared ZnO indicated the enhancement of its applicability to be used for optoelectronic applications.

scholarly journals Modeling of wood properties from parameters obtained in nursery seedlings

2018 ◽  
Vol 48 (6) ◽  
pp. 621-628
Author(s):  
Raquel Gonçalves ◽  
Rafael Gustavo Mansini Lorensani ◽  
Esther Merlo ◽  
Oscar Santaclara ◽  
Manuel Touza ◽  
...  
Keyword(s):  
Forest Management ◽  
Modulus Of Elasticity ◽  
Prediction Models ◽  
Longitudinal Velocity ◽  
Basic Density ◽  
Wood Properties ◽  
Ultrasonic Waves ◽  
Early Selection ◽  
Selection Of

Early selection of trees allows acceleration of genetic improvement, as well as processes related to forest management, to improve the quality of the wood produced; however, to reach this objective, it is necessary to know which parameters can be used as predictors of a tree’s aged condition. The objective of this research was to study parameters that are measurable in nursery seedlings and that could be used in prediction models of basic density (BDt), modulus of elasticity (EMt), and strength (fmt) of wood from trees. The tests were performed in 240 seedlings (3 and 6 months old) and in 52 trees (72 months old) from seven genetic units of two species: three Eucalyptus clones and four Pinus pinaster progenies. In the seedlings, measurements of longitudinal velocity of ultrasonic waves (VLs), basic density (BDs), height (Hs), diameter (Ds), strength (fts), and modulus of elasticity (Ets) in tension parallel to the grain were obtained. The EMt and fmt can be predicted by parameters obtained in seedlings of the same genetic unit. Thus, the use of these parameters, in association with others already used in selection programs, may increase the positive results of the early selection, with economic gains and time reductions in forest management.

Sign in / Sign up

Export Citation Format

Share Document