Pub Date : 2002-10-08DOI: 10.1109/ULTSYM.2002.1193543
K. Lakin
Coupled Resonator Filters (CRF) are a new form of bulk acoustic wave device that involves the vertical stacking of resonators. In that regard, the CRF can be thought of as a variation on the better known Stacked Crystal Filter (SCF). This paper will review the SCF and expand on the basic concepts of the CRF. Experimental results will be shown for SCFs operating to 12 GHz and CRFs near 3 GHz. Manufacturing issues associated with both filter types will be reviewed with greater emphasis on the CRF.
{"title":"Coupled resonator filters","authors":"K. Lakin","doi":"10.1109/ULTSYM.2002.1193543","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193543","url":null,"abstract":"Coupled Resonator Filters (CRF) are a new form of bulk acoustic wave device that involves the vertical stacking of resonators. In that regard, the CRF can be thought of as a variation on the better known Stacked Crystal Filter (SCF). This paper will review the SCF and expand on the basic concepts of the CRF. Experimental results will be shown for SCFs operating to 12 GHz and CRFs near 3 GHz. Manufacturing issues associated with both filter types will be reviewed with greater emphasis on the CRF.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128569450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-10-08DOI: 10.1109/ULTSYM.2002.1193560
R. Lanz, P. Carazzetti, P. Muralt
This contribution deals with surface micromachined BAW resonators based on AlN thin films. Process, design issues and first results are presented and discussed. Devices with two resonators in series having a resonance frequency between 7 and 8 GHz show promising results. Coupling coefficients of k/sub t//sup 2/ =3.8% and quality factors of 100 to 150 have been obtained with resonators having a approximate size of 30/spl times/30/spl mu/m adapted for a 50/spl Omega/ system. These results are clearly inferior to earlier results obtained with SMR designs (k/sub t//sup 2/=5.5% and Q=580). Reasons are too high serial resistances caused by bad step coverage of the top electrode, possibly also incomplete etching of the sacrificial layer, and warping by too large film stresses.
{"title":"Surface micromachined BAW resonators based on AlN","authors":"R. Lanz, P. Carazzetti, P. Muralt","doi":"10.1109/ULTSYM.2002.1193560","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193560","url":null,"abstract":"This contribution deals with surface micromachined BAW resonators based on AlN thin films. Process, design issues and first results are presented and discussed. Devices with two resonators in series having a resonance frequency between 7 and 8 GHz show promising results. Coupling coefficients of k/sub t//sup 2/ =3.8% and quality factors of 100 to 150 have been obtained with resonators having a approximate size of 30/spl times/30/spl mu/m adapted for a 50/spl Omega/ system. These results are clearly inferior to earlier results obtained with SMR designs (k/sub t//sup 2/=5.5% and Q=580). Reasons are too high serial resistances caused by bad step coverage of the top electrode, possibly also incomplete etching of the sacrificial layer, and warping by too large film stresses.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128742198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-10-08DOI: 10.1109/ULTSYM.2002.1192645
S. Inge Rabben, P. Segers, J. De Backer, J. De Sutter, P. Verdonck, T. Gillebert
In 16 subjects (age 26-74) we recorded radio-frequency (RF) data of the Carotid artery with a Vivid7 scanner (GE Vingmed Ultrasound, Horten, Norway) and Carotid diameters with WallTrack (Pie Medical, Maastricht, The Netherlands). The RF data were stored as complex demodulated radio-frequency data (IQ data) and transferred to a PC for estimation of diameter curves. For the prototype system, diameter curves are derived using a modified autocorrelation method, in contrast to Walltrack where the complex cross-correlation method is applied. For all datasets, 2-5 beats were averaged to calculate representative one-cycle curves. The diameter distension /spl Delta/D as obtained with both systems was in the range 0.27-0.71 mm, and was highly correlated (r = 0.91, p < 0.002, y = 0.99x + 0.03) with a mean difference of -0.03 mm and limits of agreement (mean difference /spl plusmn/ 2*SD of the differences) of -0.15-0.09 mm. The relative distension /spl Delta/D/D ranged from 3.5 to 11.1% and had a correlation coefficient of r = 0.92 (p < 0.002, y = 0.94x + 0.75). The mean difference of /spl Delta/D/D was -0.4%, and the limits of agreement were -2.2-1.4%. In conclusion, this study indicates that it is adequate to use the modified autocorrelation method for vessel wall tracking.
{"title":"Vessel wall tracking based on the modified autocorrelation estimator","authors":"S. Inge Rabben, P. Segers, J. De Backer, J. De Sutter, P. Verdonck, T. Gillebert","doi":"10.1109/ULTSYM.2002.1192645","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192645","url":null,"abstract":"In 16 subjects (age 26-74) we recorded radio-frequency (RF) data of the Carotid artery with a Vivid7 scanner (GE Vingmed Ultrasound, Horten, Norway) and Carotid diameters with WallTrack (Pie Medical, Maastricht, The Netherlands). The RF data were stored as complex demodulated radio-frequency data (IQ data) and transferred to a PC for estimation of diameter curves. For the prototype system, diameter curves are derived using a modified autocorrelation method, in contrast to Walltrack where the complex cross-correlation method is applied. For all datasets, 2-5 beats were averaged to calculate representative one-cycle curves. The diameter distension /spl Delta/D as obtained with both systems was in the range 0.27-0.71 mm, and was highly correlated (r = 0.91, p < 0.002, y = 0.99x + 0.03) with a mean difference of -0.03 mm and limits of agreement (mean difference /spl plusmn/ 2*SD of the differences) of -0.15-0.09 mm. The relative distension /spl Delta/D/D ranged from 3.5 to 11.1% and had a correlation coefficient of r = 0.92 (p < 0.002, y = 0.94x + 0.75). The mean difference of /spl Delta/D/D was -0.4%, and the limits of agreement were -2.2-1.4%. In conclusion, this study indicates that it is adequate to use the modified autocorrelation method for vessel wall tracking.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129009635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-10-08DOI: 10.1109/ULTSYM.2002.1192638
H. Horinaka, T. Iwade, Y. Kanetaka, K. Wada, T. Matsunaka
A new imaging method using the interaction between the near infrared light and the ultrasonic wave was investigated for application to medical diagnosis. The method was applied to a biological tissue (a dog stomach) including absorbers. The ultrasonic echo pulse from absorbers in the biological tissues shifted due to the illumination of laser diode. The image reconstructed from the shift of ultrasonic echo pulses revealed the shape of the absorber hidden in the biological tissue.
{"title":"New imaging method using ultrasonic velocity change caused by light absorption","authors":"H. Horinaka, T. Iwade, Y. Kanetaka, K. Wada, T. Matsunaka","doi":"10.1109/ULTSYM.2002.1192638","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192638","url":null,"abstract":"A new imaging method using the interaction between the near infrared light and the ultrasonic wave was investigated for application to medical diagnosis. The method was applied to a biological tissue (a dog stomach) including absorbers. The ultrasonic echo pulse from absorbers in the biological tissues shifted due to the illumination of laser diode. The image reconstructed from the shift of ultrasonic echo pulses revealed the shape of the absorber hidden in the biological tissue.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129147995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-10-08DOI: 10.1109/ULTSYM.2002.1193397
Y. Aoki, H. Yoshida, K. Koh, C. Kaneshiro, K. Hohkawa
In this paper, we present the design of a novel SAW amplifier that consists of multi-stripe tapping electrodes and a GaAs FET amplifier. Using a general circuit simulator, we analyse the frequency characteristics of the SAW amplifier. The SAW amplifier with differential operation shows wideband frequency characteristics better than that without differential operation. We also investigate the frequency characteristics by changing tapping electrode pitches and the impedance matching condition between SAW and FET. These results confirm that the SAW amplifier is applicable to wideband communication systems and signal processing systems.
{"title":"Design of SAW amplifier with distributed semiconductor transistor","authors":"Y. Aoki, H. Yoshida, K. Koh, C. Kaneshiro, K. Hohkawa","doi":"10.1109/ULTSYM.2002.1193397","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193397","url":null,"abstract":"In this paper, we present the design of a novel SAW amplifier that consists of multi-stripe tapping electrodes and a GaAs FET amplifier. Using a general circuit simulator, we analyse the frequency characteristics of the SAW amplifier. The SAW amplifier with differential operation shows wideband frequency characteristics better than that without differential operation. We also investigate the frequency characteristics by changing tapping electrode pitches and the impedance matching condition between SAW and FET. These results confirm that the SAW amplifier is applicable to wideband communication systems and signal processing systems.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129367951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-10-08DOI: 10.1109/ULTSYM.2002.1193449
D. Powell, K. Kalantar-zadeh, S. Ippolito, W. Wlodarski
Surface Acoustic Wave (SAW) sensors comprising a zinc oxide guiding layer deposited on a 36/spl deg/-YX lithium tantalate substrate were developed. They were found to have greater mass sensitivity than other LiTaO/sub 3/ based SAW sensors, such as the -SiO/sub 2//LiTaO/sub 3/ configuration. In this paper, the fabrication of the ZnO/LiTaO/sub 3/ sensor is described and micro-characterisation of the deposited films is presented. Sensitivity of these devices to surface mass and dielectric perturbations is then presented, followed by an analysis of temperature stability.
{"title":"A layered SAW device based on ZnO/LiTaO/sub 3/ for liquid media sensing applications","authors":"D. Powell, K. Kalantar-zadeh, S. Ippolito, W. Wlodarski","doi":"10.1109/ULTSYM.2002.1193449","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193449","url":null,"abstract":"Surface Acoustic Wave (SAW) sensors comprising a zinc oxide guiding layer deposited on a 36/spl deg/-YX lithium tantalate substrate were developed. They were found to have greater mass sensitivity than other LiTaO/sub 3/ based SAW sensors, such as the -SiO/sub 2//LiTaO/sub 3/ configuration. In this paper, the fabrication of the ZnO/LiTaO/sub 3/ sensor is described and micro-characterisation of the deposited films is presented. Sensitivity of these devices to surface mass and dielectric perturbations is then presented, followed by an analysis of temperature stability.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129543037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-10-08DOI: 10.1109/ULTSYM.2002.1192527
Y. Estanbouli, G. Hayward, J. Barbenel
Despite significant advances in ultrasonic instrumentation, accurate and repeatable measurements of skin structure and dimensions remain problematic. Skin structure is complicated and structural boundaries are non-planar and may be diffuse, inhibiting the application of inversion methods for skin thickness measurement. Coupling a transducer to the skin surface with water or aqueous gel can produce significant artefacts in thickness measurement, which may be prevented by using a rubber dry contact. This work describes a theoretical investigation of these problems, using the PZFlex finite element code as a virtual prototyping tool. Simulations show that non-planar and diffuse boundaries have significant effect on the output backscattered signals; and using of low loss rubber dry contact is possible but further work is required to determine the properties and optimum shape of the rubber interface.
{"title":"A theoretical investigation of ultrasonic transducer design for measurement of skin","authors":"Y. Estanbouli, G. Hayward, J. Barbenel","doi":"10.1109/ULTSYM.2002.1192527","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192527","url":null,"abstract":"Despite significant advances in ultrasonic instrumentation, accurate and repeatable measurements of skin structure and dimensions remain problematic. Skin structure is complicated and structural boundaries are non-planar and may be diffuse, inhibiting the application of inversion methods for skin thickness measurement. Coupling a transducer to the skin surface with water or aqueous gel can produce significant artefacts in thickness measurement, which may be prevented by using a rubber dry contact. This work describes a theoretical investigation of these problems, using the PZFlex finite element code as a virtual prototyping tool. Simulations show that non-planar and diffuse boundaries have significant effect on the output backscattered signals; and using of low loss rubber dry contact is possible but further work is required to determine the properties and optimum shape of the rubber interface.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123605436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-10-08DOI: 10.1109/ULTSYM.2002.1192584
R. F. Kerr, M.E. Anderson
We present the results of a study exploring the upper velocity limit of vector flow estimation with Heterodyned Spatial Quadrature. Since this is highly dependent on apodization, we investigated a set of apodization windows designed to explore means of extending the practical velocity range. Heterodyned Spatial Quadrature (HSQ) is a recently described vector flow technique that has been shown to provide accurate flow estimates in both the axial and lateral directions. The complex PSF created by this technique induces a modulation in the received echo of a scatterer traversing the resolution volume at a frequency proportional to the scatterer lateral velocity. We measure the rate of phase change of this modulation to provide an estimate of the lateral flow velocity component. The technique is extendible to 3D vector flow estimation with a 2D array. We expect lateral tracking methods in general to be limited by a number of factors including the PSF beam width and the system amplitude sensitivity. Using a Siemens Elegra ultrasound scanner with a 7.5 MHz linear array, we simulated flow up to 405 /spl mu/m per step in a tissue-mimicking phantom, corresponding to velocities up to 4.05 m/sec for a PRF of 10 kHz, at Doppler angles of 60/spl deg/ and 90/spl deg/. We estimated lateral velocities to within 5% relative bias up to 315 cm/sec in an f/2 geometry at a 90/spl deg/ Doppler angle. The spatial quadrature receive aperture utilized a bi-lobed Blackman apodization with a width of 1/2D, where D is the full width of the array. Computer simulations of the system under similar conditions produced lateral velocity estimates up to 303 cm/sec. As expected, the maximum estimable velocity scales with focal depth. In simulations, the same aperture estimated flow velocities up to 672 cm/sec at a focal depth of 75 mm, representing an f/5 geometry.
{"title":"Aperture design analysis for vector flow imaging","authors":"R. F. Kerr, M.E. Anderson","doi":"10.1109/ULTSYM.2002.1192584","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192584","url":null,"abstract":"We present the results of a study exploring the upper velocity limit of vector flow estimation with Heterodyned Spatial Quadrature. Since this is highly dependent on apodization, we investigated a set of apodization windows designed to explore means of extending the practical velocity range. Heterodyned Spatial Quadrature (HSQ) is a recently described vector flow technique that has been shown to provide accurate flow estimates in both the axial and lateral directions. The complex PSF created by this technique induces a modulation in the received echo of a scatterer traversing the resolution volume at a frequency proportional to the scatterer lateral velocity. We measure the rate of phase change of this modulation to provide an estimate of the lateral flow velocity component. The technique is extendible to 3D vector flow estimation with a 2D array. We expect lateral tracking methods in general to be limited by a number of factors including the PSF beam width and the system amplitude sensitivity. Using a Siemens Elegra ultrasound scanner with a 7.5 MHz linear array, we simulated flow up to 405 /spl mu/m per step in a tissue-mimicking phantom, corresponding to velocities up to 4.05 m/sec for a PRF of 10 kHz, at Doppler angles of 60/spl deg/ and 90/spl deg/. We estimated lateral velocities to within 5% relative bias up to 315 cm/sec in an f/2 geometry at a 90/spl deg/ Doppler angle. The spatial quadrature receive aperture utilized a bi-lobed Blackman apodization with a width of 1/2D, where D is the full width of the array. Computer simulations of the system under similar conditions produced lateral velocity estimates up to 303 cm/sec. As expected, the maximum estimable velocity scales with focal depth. In simulations, the same aperture estimated flow velocities up to 672 cm/sec at a focal depth of 75 mm, representing an f/5 geometry.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121198488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-10-08DOI: 10.1109/ULTSYM.2002.1192572
A. Watanabe, T. Takatera, T. Sato, S. Takeuchi, H. Nishimura, N. Kawashima
The effect of ultrasound exposure on cancer cell proliferation properties and its mechanism has been studied in our laboratory. The suppression of cancer cells proliferation rate in the culturing process after ultrasound exposure was confirmed. We suppose that the inertial cavitation generated by ultrasound exposure induced the apoptosis in the cancer cells. It was found with a digital microscope that the shape of the cancer cells did not change remarkably immediately after ultrasound exposure, but the cancer cells exposed to ultrasound shrunk gradually with passage of culturing time. Ladder patterns of electrophoresis were observed in the agarose gel with apoptosis induced cancer cells with ultrasound exposure. Therefore, it can be thought that the suppression of cancer cells proliferation by ultrasound exposure was caused by induction of apoptosis in the cancer cells.
{"title":"Study on suppression mechanism of cancer cells proliferation by ultrasound exposure for minimally invasive cancer treatment","authors":"A. Watanabe, T. Takatera, T. Sato, S. Takeuchi, H. Nishimura, N. Kawashima","doi":"10.1109/ULTSYM.2002.1192572","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192572","url":null,"abstract":"The effect of ultrasound exposure on cancer cell proliferation properties and its mechanism has been studied in our laboratory. The suppression of cancer cells proliferation rate in the culturing process after ultrasound exposure was confirmed. We suppose that the inertial cavitation generated by ultrasound exposure induced the apoptosis in the cancer cells. It was found with a digital microscope that the shape of the cancer cells did not change remarkably immediately after ultrasound exposure, but the cancer cells exposed to ultrasound shrunk gradually with passage of culturing time. Ladder patterns of electrophoresis were observed in the agarose gel with apoptosis induced cancer cells with ultrasound exposure. Therefore, it can be thought that the suppression of cancer cells proliferation by ultrasound exposure was caused by induction of apoptosis in the cancer cells.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121675804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-10-08DOI: 10.1109/ULTSYM.2002.1193536
Shih-Jeh Wu, C. Jeng, Jow-Lay Huang
Chromium carbide (Cr/sub 3/C/sub 2/) has been proved to be a potential material for toughening alumina in biomedical and industrial applications because of its high Young's modulus and erosion resistance. On the other hand, TiC/Al/sub 2/O/sub 3/ composite has been used a magnetic head slider due to its good wear resistance and mechanical strength. In this study we prepare samples of Cr/sub 3/C/sub 2//Al/sub 2/O/sub 3/ composite by injection moulding method. To use this ceramic material as structural components when the temperature varies rapidly, it is necessary to be able to estimate damage or thermal shock cracking. Ultrasonic attenuation measurements are made for assessment of thermal shock damage. Results show that the attenuation increases as the shock temperature raises. Corresponding SEM pictures show although the size of micro-crack doesn't change the depth of the micro-cracks increases. It is demonstrated that ultrasonic attenuation proves to be a reliable tool for evaluating micro-fractures in solids.
{"title":"Ultrasonic evaluation of thermally shocked Cr/sub 3/C/sub 2//Al/sub 2/O/sub 3/","authors":"Shih-Jeh Wu, C. Jeng, Jow-Lay Huang","doi":"10.1109/ULTSYM.2002.1193536","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193536","url":null,"abstract":"Chromium carbide (Cr/sub 3/C/sub 2/) has been proved to be a potential material for toughening alumina in biomedical and industrial applications because of its high Young's modulus and erosion resistance. On the other hand, TiC/Al/sub 2/O/sub 3/ composite has been used a magnetic head slider due to its good wear resistance and mechanical strength. In this study we prepare samples of Cr/sub 3/C/sub 2//Al/sub 2/O/sub 3/ composite by injection moulding method. To use this ceramic material as structural components when the temperature varies rapidly, it is necessary to be able to estimate damage or thermal shock cracking. Ultrasonic attenuation measurements are made for assessment of thermal shock damage. Results show that the attenuation increases as the shock temperature raises. Corresponding SEM pictures show although the size of micro-crack doesn't change the depth of the micro-cracks increases. It is demonstrated that ultrasonic attenuation proves to be a reliable tool for evaluating micro-fractures in solids.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"78 15","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113940818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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