Non-Contact Ultrasound CERAMIC ANALYSIS, INCLUDING REFRACTORIES & FILTERS SecondWave M510Ultrasonic Analysis System
Introduction Contact or water immersion ultrasound does provide significant information about materials quality and properties. But, it cannot be applied to the early stages of materials formation - when they are tacky or fragile. It is also not reliable for materials that are porous, liquid sensitive, or when any type of contact with a material is cumbersome. Non-Contact Ultrasound (NCU) is the most desirable choice for such applications. Ultran has been working to facilitate NCU since 1978. In 1997, Ultran created internationally patented piezoelectric transducers characterized by phenomenal efficiency in air and other gases with frequencies from 50 khz to 5.0 MHz. Complementing the NCU transducers are Ultran s equally novel ultrasonic imaging systems and analyses software. The SecondWave M510 is a focused non-contact ultrasonic analysis system that is customer-friendly and understands the significance of materials testing and analysis, including the speeds required to accomplish a task. The M510 supports through transmission, same-side and pulse-echo techniques. M510 single and multichannel systems have been fully configured and installed for on-line (production line) and off-line (bench top) analysis of green ceramics, green alumina, refractory blocks, sintered ceramic tiles and compressed powders. M510 capabilities High resolution detection of cracks and other conditions in ceramic products Green stage materials evaluation. Moisture estimation. Determination of density/porosity, texture and other properties SecondWave M510 Components NCU Transducers Ultran s transducers boast the highest efficiency devices among non-contact transducers approaching those of conventional contact transducers. Frequency Range: 50 khz - 5.0 MHz. Active dimensions: 1.0 mm - 500mm. with planar, point, parabolic, and compound beam geometry. Robust lightweight construction. Scanning: Vertical or horizontal acoustic bench, single or multi-transducer multi-axis scanning frames. System Instrumentation 4U industrial grade unit incorporating Intel Core2 Quad processors, 2 GB RAM, RAID5 Serial ATA hard drives and redundant power supplies. Integrated are: Pulser: PCI-based 375V RF toneburst pulser with 50 khz to 5 MHz range, adjustable bursts, voltage and PRF. Receiver: Internal 1-8 channel low-noise amplifier with 80 db gain and 10 MHz bandwidth, multi-value low and high pass filters. DAQ: 14 bit Analog to Digital Converter with 50 MHz sample rate and on-board 256 MB storage. Multi-axis encoder inputs for motion synchronized acquisition. Software SecondWave Studio: Windows XP-based A-Scan and C-Scan software with user-friendly GUI. Displays rolling single and multi-channel C-Scans. Capture and storage of full-wave data for scans. Project Manager with multiple access levels. SQL Database integration. SecondWave Research Studio: C-Scan and A-Scan post-processing software. Generates cross-sectional material profiles. Parametric correlation to determine material density, porosity and fiber orientation. Image processing functions to find and highlight defects. 2 SecondWave M510 shown with single and multi-channel transducers on different materials
3 Non-contact ultrasound techniques Direct transmission AIR T Air + Test Material Transmission Surface Reflections Defect, crack, delamination detection Velocity, time-of-flight, thickness measurements Oblique incidence & refraction for shear wave and anisotropy measurements AIR R Thickness Reflections Same side transmitter-receiver pitch-catch Defect, delamination, corrosion detection Location of discontinuities T R AIR Surface Waves Longitudinal/Shear Waves Single transducer pulse-echo Surface profiling Surface acoustic analysis Reflectance measurements Depth measurement Object identification AIR Ultrasonic reflection image Quantitative detectability example Detection of side drilled holes (varying from 0.5 to 6.3 mm) in 10 mm PMMA with direct NCU transmission 1.0 MHz
4 Observations and case studies by direct transmission and same side NCU imaging (All images generated without signal post-processing, and in most cases no signal averaging was used) Green Ceramics: Density and moisture determination 860 840 820 y = 536.21x - 190.68 R 2 = 0.9751 Fig. 1. Density of green alumina from ultrasound velocity - 500 khz Velocity (m/s) 800 780 760 740 720 700 1.65 1.7 1.75 1.8 1.85 1.9 1.95 Density (g/cc) Fig. 2. Moisture as a function of time in floor tile samples. 500 khz Fig. 3. Density vs. transmittance relationship for green and dry samples of floor tiles Fig. 4. Image of a green floor tile, presumably indicating subtle density variations 500 khz Fig. 5. Relative transmittance in samples of green alumina pressed at different pressures; left at 9000 psi and right at 12,000 psi - 500 khz
5 Sintered Ceramics & refractories: Density and defect detection Fig. 6. Relative transmission in alumina varying in density. Left: 64.8%, 2.58 g/cc. Middle: 70.3%, 2.80g/cc. Right: 77.3%, 3.08 g/cc.- 500 khz Fig. 7. Alumina refractory, without cracks (left) and with cracks (right.) 500 khz Fig. 8. Fused silica refractory, assumed to be without defects. Note the left hand portion is severely cracked internally - 200 khz.
6 Fig. 9. Power Metal (Green Iron Compact Left: Transmission (db) Right: Velocity (m/s) Fig. 10. Semiconductor alumina abrasive disc -Subtle microstructure variations -Higher transmission is indicative of low density high porosity Non-Defective Defective Fig. 11. Fused silica kiln furniture. Left: without defects, however, it exhibits either gross porosity or internal cracks. Right: With severe internal cracks with the exception of small left hand region, it is completely delaminated - 500 khz.
7 Fig. 12. Steel making refractory blocks. Left, with severe internal cracks and defects. Right, without defects - 200 khz.
8 Conclusions Ultran s SecondWave M510 ultrasonic imaging and analysis system is characterized by a wide range of frequencies from 50 khz to 5.0 MHz. This makes it possible to apply non-contact ultrasound (NCU) for ceramic and sintered metal evaluation all the way from early stages of their formation to finished products. Typical applications include crack detection, moisture detection, porosity and texture analysis, properties, etc. The M510 is a powerful tool for materials process analysis and QC, directly saving you cost, energy, and materials, besides assuring the quality and reliability of your materials. Sales representatives HEAD OFFICE The Ultran Group 3100 Research Drive State College, PA 16801 USA Tel: +1.814.466.6200 Fax: +1.814.466.6847 Email: info@ultrangroup.com ITALY Pierluigi Carni Via B. Angelico, 1 24047 Treviglio BG, Italy Tel: +39 340 9125410 Email: plcarni@atenatec.it UK What Ultran provides We supply complete NCU systems suitable for customers needs. These include specifically designed transducer libraries so that our customers can start characterizing all their materials from Day 1. Ultran also supplies custom NCU systems geared for production (online) configured to customers applications and environment of testing. Under agreements, Ultran will transfer science and technology - targeted to customer needs. We offer hands-on training to all our customers. We maintain a fully-stocked ultrasound materials analytical laboratory and we are fully equipped to provide feasibility, in-depth analysis, and R&D for our customers. Sonatest NDTS Jenny Hough Units 1-3 Prospect House, Colliery Close, Ireland Business Park, Staveley, Chesterfield, S41 8NG, UK Tel: +44 (0) 1246 474269 Fax: +44 (0) 1246 474089 Email: jenny.hough@sonatest.com JAPAN Ken Automation Tatsuya Yaoita Hiranuma 1-11-12 Yokohama KMH Bldg., Nishi-Ku Yokohama - 220-0023 Tel: +81.45.290.0432 Fax: +81.45.321.6590 Email: yaoita@kenautomation.com CHINA Matrix U/E Technologies Inc. Jiang Yunxi Chaoyang District, Beijing Wangjing Litse emerging industries in Park District No. 106 Building 402B Tel:+86-10-64391208-819 Mobile: 0086-13910978697 E-Mail: jiangyunxi@matrixndt.com INDIA Speck Systems Ltd. D Simon Amallraja B-49, Electronics Complex Kushaiguda, Hyderabad-500062 Tel: +91-40-27125305 Fax: +91-40-27122489 Email: samallraja@specksystems.co.in