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Uttenreuth, Germany

Weidner M.,MEDAV GmbH | Ernst E.,GKN plc
International Powder Metallurgy Congress and Exhibition, Euro PM 2013 | Year: 2013

Acoustic Resonance Testing (ART) provides an economic solution for line-integrated quality testing to manufacturers of powder-metallurgical parts (see Ref. [1] - [5]). The technique convinces through a high degree of reliability, short measurement cycles for complete component testing and relatively small cost investment. The method uses the fact, that on modern lines mainly faultless parts are produced. It sorts out conspicuous parts, which show acoustic characteristics different from the bulk. After changes of material or production parameters, a new adaption of the abnormality limits is performed. This adaptation has to be stable against changing production scatter. That means that the system's sensitivity against faulty parts within a very homogenous production lot should be comparable to the selectivity necessary to sort out all conspicuous parts within an untypically inhomogeneous production lot. The subsequent contribution discusses how such comparable test conditions can be achieved even if the absolute extent of production scatter differs from lot to lot. Source


Weidner M.,MEDAV GmbH | Ernst E.,GKN plc
Euro PM 2014 Congress and Exhibition, Proceedings | Year: 2014

Acoustic Resonance Testing (ART) provides an economic solution for line-integrated quality testing of all kinds of powder-metallurgical or MIM parts. The assessed characteristics directly depend on geometry, density, mass, elastic modulus and stiffness and therefore relate to the steadiness of the component. ART is a comparative method. It sorts out conspicuous parts, which show acoustic characteristics different from the bulk. The technique convinces through a high degree of reliability, short measurement cycles for complete component testing and relatively small cost investment. The subsequent contribution discusses the characteristics of two different ways to achieve sound excitation, namely by an impact device, which is a small electro-mechanical hammer, or by a slide device, where parts fall down on an impingement plate. Based on theoretical and practical considerations, criteria for the choice of the best method for signal generation are presented. Different installations for testing PM and MIM parts at GKN Sinter Metals are presented as example. Source


Strama O.,MEDAV GmbH | Ernst E.,GKN plc
Proceedings of the International Euro Powder Metallurgy Congress and Exhibition, Euro PM 2012 | Year: 2012

As practice shows, with the help of the Acoustic Resonance Testing (ART) cracks and other quality related issues can be found in test specimens. To make this technique interesting for powder metal production environments from the technical and the economical point of view, a number of requirements have to be taken into account. Today, high quality requirements are in contradiction to the challenge, to provide even security-related components at a low price per part. This, on the other hand, requires quality testing methods, which are able to detect quality related issues with high speed and low operating costs. This contribution shows how these conflicting requirements can be solved by Acoustic Resonance Testing. Starting from the basics of this technique, particular these points are referenced, which are crucial for stable long-time operation at the PM production. One of the main requirements is the assessment of the typical production scatter. Usually, the issues to be detected have smaller influences on the resonance frequencies than the production deviations over a long time. The presented MEDAV technique allows detection of conspicuous parts in a series of produced parts, even if they are covered by the overall production scatter. This is solved by an automatic and adaptive algorithm, which can be optimized by a so called quality evaluation loop to avoid pseudo rejects by simultaneously detection of relevant issues. Source


Muller R.,TU Ilmenau | Wollenschlager F.,TU Ilmenau | Schulz A.,TU Ilmenau | Elkhouly M.,Ihp Microelectronics | And 5 more authors.
Proceedings of 6th European Conference on Antennas and Propagation, EuCAP 2012 | Year: 2012

For high-data-rate multimedia access and measurement applications (such as channel sounding and radar) the 60 GHz unlicensed band is of interest for short range applications. Currently, there is enormous progress in the field of monolithic-millimeter-wave-integrated-circuits (MMIC) for 60 GHz technology, but there are still many challenges related to reliability and usable bandwidth for compact packaging solutions. The aim of this work is to demonstrate the implementation of miniaturized 60 GHz front-ends, including fully differential MMICs, with gain control and phase-shifting capabilities, interconnected to a broadband differentially fed waveguide for the WR-15 standard. The front-ends were designed based on MMICs using 0.25 m SiGe BiCMOS and packaging on low-temperature-cofired-ceramics (LTCC) technology. We have designed, simulated, fabricated, and tested the front-ends showing a useable bandwidth of more than 12 GHz at the 60 GHz band fulfilling the requirements of the IEEE 802.11ad standard. © 2012 IEEE. Source


Malz E.,TU Ilmenau | Thoma R.S.,TU Ilmenau | Zetik R.,TU Ilmenau | Semashko P.,TU Ilmenau | Ariza A.P.G.,MEDAV GmbH
Proceedings - IEEE International Conference on Ultra-Wideband | Year: 2012

In this article we give an overview about the principles of polarimetric Ultrawideband Radar. Starting from the state of the art and a summary of the theory we analyze the calibration principles of polarized UWB Radar Data, we investigate possible imaging algorithms and we list important applications. Finally we show an example, to detect certain targets using a polarimetric MIMO UWB radar by doing an analysis of the radar cross section (RCS) of the individual targets. © 2012 IEEE. Source

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