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Correlation of thin-film bond compliance and bond fracture resistance
microscope has a space resolution of 20 micro meters, a scanning area of 5 x 5 ram, and a line-scanning time that is variable within 2- 120 sec. The number of lines can be set at 32, 64, 128, or 256. 40632
Fatkin, D.G.P.; Scruby, C.B.; Briggs, G.A.D.
Review - acoustic microscopy of low-ductility materials Journal of Materials Science, Vol. 24, No. 1, pp. 23-40 (Jan. 1989) This paper describes the application of acoustic microscopy to two important classes of low-ductility material: engineering ceramics and ceramic-fibre composites. Images of a wide range of near-surface defects are presented for the six ceramics studied, including porosity and microcracks. An application to crack length determination during indentation tests is also discussed. In the composites, there were systematic variations in contrast from the fibre-matrix interface, which appeared to correlate with changes in interfacial strength. Finally, the line-focus microscope was used to demonstrate how the Rayleigh velocity and attenuation can be used to characterize the micro-structure of ceramics and ceramic composites. 40616
Cheeke, J.D.N.
Cryogenic acoustic microscopy Ultrasonic Methods in Evaluation of Inhomogeneous Materials, Proceedings, Erice, (Italy), 15-25 Oct. 1985, pp. 123-162. Edited by A. Alippi and W.G. Mayer. Nato Advanced Study Institute Series E Applied Sciences, Vol. 126, Martinus Nijhoff, 1987 This course of three lectures is focussed on one particular aspect of the scanning acoustic microscope SAM, that of low temperature microscopy. The first lecture deals with basic principles of the SAM; lens characteristics, choice of the liquid, imaging properties of the SAM, reflectance function, materials signatures of V(z) and ideas on the origin of contrast. The second lecture treats the question of nonlinear effects in fluids. These effects are pronounced at low temperatures which is the subject of the third lecture. 40576
Yi, G.; Wu, Z.; Sreenivas, K.; Sayer, M.
Ultrasonic experiments with lead zirconate titanate thin films fabricated by sol gel processing Electronics Letters, Vol. 25, No. 5, pp. 307-309 (2 Mar. 1989) Surface and bulk acoustic wave measurements with lead zirconate titanate (PZT) thin films fabricated by a sol gel processing technique are reported for the first time. The piezoelectricity of such films was achieved by poling. Good acoustic properties of these films are confirmed by the acoustic images and V(z) curves obtained by a scanning acoustic microscope. 40407
Lawrence, C. W.; Scruby, C.B.; Briggs, G.A.D.; Dunhill, A.
Crack detection in silicon nitride by acoustic microscopy United Kingdom Atomic Energy Authority, Harwell, A E R E - R 13196, 22 pp. (Dec. 1988) This paper reports the application of acoustic microscopy to the detection of critical defects in a test block and in a finished ball bearing component, both of which were manufactured from the same silicon nitride material. The data demonstrate the importance of choosing a sufficiently high frequency in order to detect shallow surface-opening cracks. Thus defects that could not be detected or resolved at 250 MHz, were resolvable at 400 MHZ. 40286
Issouckis, M.
Scanning acoustic microscopy - principles and applications Metals and Materials, Vol. 5, No. 2, pp. 63-67 (Feb. 1989) Acoustic microscopy is a relatively new technique which offers materials scientists the ability to image surface or sub-surface structures according to variations in their elastic properties, and its applications encompass a wide range of materials. This article describes the basic principles of acoustic microscopy and its use in materials science in the study of ceramics, polymers, composites, metals and semiconductor materials. The author considers the imaging capabilities of the technique and describes its quantitative aspects and use in material characterisation. 40241
Khandelwal, P.K.
Nondestructive evaluation (NDE) of structural ceramics by photoaeoustic microscopy General Motors Corp., Indianapolis, IN (United States) N88-23884, 7 pp. (May 1986) Photoacoustic microscopy (PAM) was utilized to detect surface and subsurface defects in structural ceramic materials. A computerized PAM data acquisition, color imaging and analysis system was developed and used. Subsurface simulated cylindrical holes can be detected to about 1 mm below the interrogating surface. Simulated tight surface cracks of 96 microns length and 48 microns depth can be detected in these materials under optimum conditions. 40240
Vary, A.
Nondestructive evaluation of structural ceramics National Aeronautics and Space Administration, Cleveland, OH. Lewis Research Center (United States) N88-23876, 12 pp. (May 1986) Research on nondestructive evaluation (NDE) of structural ceramics for heat engine applications is reviewed. Microfocus radiography and scanning laser acoustic microscopy are the NDE techniques highlighted. The techniques were applied to research samples of sintered silicon nitride and silicon carbide in the form of modulus-of-rupture (MOR) bars. The strength and limitations of the aforementioned techniques are given in terms of probability of detection for voids in green and sintered MOR bars. Voids for this purpose were introduced by seeding green ceramic bars and characterizing each void in terms of its size,
NDT International February 1990
shape, location, and nature before and after sintering. The effects of materials density, microstructure, surface finish, thickness, void depth, and size characteristics on detectability are summarized. 40194
Ringermacher, H.L; Bak, M.
Thermomechanical contrast mechanism in thermoacoustic imaging for NDE Review of Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States), 22-26 Jun. 1987. Vol. 7A, pp. 239-244. Edited by D . D . T h o m p s o n and D.E.Chimenti, Plenum Press, 1988. An unusual thermoacoustic image has been observed using Scanning Electron Microscopy (SEAM), of a prepared subsurface groove in a calibration specimen. An exceptionally clear thermoacoustic image was obtained of the subsurface portion of the groove even in the region where the groove depth exceeded 25 thermal diffusion lengths of the thermal wave at the operating modulation frequency. This was clearly not a thermal wave image. At that time is was proposed that this was a new contrast mechanism which was essentially an image of the local compliance of the plate- that is, a thermomechanicai image. In the present work, the thermomechanical contrast mechanism is verified using a finite element analysis employing a purely thermomechanical formulation. The analysis is time independent and also independent of the temperature distribution of the ingoing thermal wave. A single thermal element constant energy loading is assumed to produce the specimen's mechanical response. 40192
Favro, L.D.; Shepard, S.M.; Kuo, P.K.; Thomas, R.L.
Sound producing mechanisms in thermoaconstic microscopes Review of Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States), 22-26 Jun. 1987. Voi. 7A, pp. 225-229. Edited by D . D . T h o m p s o n and D.E.Chimenti, Plenum Press, 1988. Thermoacoustic microscopes generate sound in a solid by using a focussed laser or particle beam to deposit energy and momentum in a localized region just beneath the samples surface. These beams may be either pulsed or periodically modulated and generate sound either through thermal expansion effects or through direct momentum transfer to the lattice. In general both longitudinal and transverse (as well as surface) sound waves and thermal waves are generated. For purposes of microscopy, sources which are much more nearly approximated by a point are used, and the operation is usually in the frequency domain, i.e., with a periodically modulated source. Therefore a model is needed of the sound generation for a periodic point source. In this paper an exact solution to the thermoelastic equations with such a source is described. Although all of the details are not discussed in this paper, the solution, being exact, describes all of the thermal and elastic wave modes, in the bulk and on the surface. 40075
Fanton, J.T.; Chou, C.-H.; Khuri-Yakub, B.T.; Kino, G.S.
Evaluation of solder bonds in a silicon flip chip device Review of Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States), 22-26 Jun. 1987. Vol. 7B, pp. 1195-1202. Edited by D.D. T h o m p s o n and D.E. Chimenti, Plenum Press, 1988. Recently two nondestructive testing techniques were adapted for the evaluation of electrical connections between a silicon device wafer and an inverted silicon interconnect chip. A focused acoustic microscope was used to check the mechanical quality of the connections, and a photothermal probe was used to measure their electrical conductivity. With the combination of these two techniques, differences can be observed between good bonds, partial disbonds, and complete open circuits. The type of disbond can also be determined. 40074
Addison, R.C. Jr.; Marshal[, D.B.
Correlation of thin-film bond compliance and bond fracture resistance Review of Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States), 22-26 Jun. 1987. Vol. 7B, pp. 1185-1194. Edited by D.D. Thompson and D.E. Chimenti, Plenum Press, 1988. The integrity of the interracial bond between a coating and its substrate is of primary importance for any application. Scanning acoustic microscopy (SAM) provides a method for making localized measurements of film disbonds and film bond compliance based on the changes in the surface acoustic wave velocity in the layered medium, The results of these measurements for chrome/gold and gold films on glass substrates are summarized. An experiment to determine if this correlation exists for chrome/gold and gold films on sapphire substrates is described. Results of such an experiment would provide an empirical correlation between surface acoustic wave velocity measurements and the fracture energy of the film. The results of an experiment to measure the fracture energy of the interfacial bond between a gold film and the sapphire substrate are described.
40064 Thomas, G.; Odegard, B.C. Inspecting advanced composite materials at ultrasonic frequencies from 2 megahertz to 2 gigahertz Review of Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States), 22-26 Jun. 1987. Vol. 7B, pp. 1003-1010. Edited by D.D. T h o m p s o n and D.E. Chimenti, Plenum Press, 1988. Ultrasonic nondestructive evaluation is an effective method of evaluating various types of composite materials for defects. This paper discusses the role ultrasonic nondestructive evaluation performed in studying the impact tolerance
41
Fatkin, D.G.P.; Scruby, C.B.; Briggs, G.A.D.
Review - acoustic microscopy of low-ductility materials Journal of Materials Science, Vol. 24, No. 1, pp. 23-40 (Jan. 1989) This paper describes the application of acoustic microscopy to two important classes of low-ductility material: engineering ceramics and ceramic-fibre composites. Images of a wide range of near-surface defects are presented for the six ceramics studied, including porosity and microcracks. An application to crack length determination during indentation tests is also discussed. In the composites, there were systematic variations in contrast from the fibre-matrix interface, which appeared to correlate with changes in interfacial strength. Finally, the line-focus microscope was used to demonstrate how the Rayleigh velocity and attenuation can be used to characterize the micro-structure of ceramics and ceramic composites. 40616
Cheeke, J.D.N.
Cryogenic acoustic microscopy Ultrasonic Methods in Evaluation of Inhomogeneous Materials, Proceedings, Erice, (Italy), 15-25 Oct. 1985, pp. 123-162. Edited by A. Alippi and W.G. Mayer. Nato Advanced Study Institute Series E Applied Sciences, Vol. 126, Martinus Nijhoff, 1987 This course of three lectures is focussed on one particular aspect of the scanning acoustic microscope SAM, that of low temperature microscopy. The first lecture deals with basic principles of the SAM; lens characteristics, choice of the liquid, imaging properties of the SAM, reflectance function, materials signatures of V(z) and ideas on the origin of contrast. The second lecture treats the question of nonlinear effects in fluids. These effects are pronounced at low temperatures which is the subject of the third lecture. 40576
Yi, G.; Wu, Z.; Sreenivas, K.; Sayer, M.
Ultrasonic experiments with lead zirconate titanate thin films fabricated by sol gel processing Electronics Letters, Vol. 25, No. 5, pp. 307-309 (2 Mar. 1989) Surface and bulk acoustic wave measurements with lead zirconate titanate (PZT) thin films fabricated by a sol gel processing technique are reported for the first time. The piezoelectricity of such films was achieved by poling. Good acoustic properties of these films are confirmed by the acoustic images and V(z) curves obtained by a scanning acoustic microscope. 40407
Lawrence, C. W.; Scruby, C.B.; Briggs, G.A.D.; Dunhill, A.
Crack detection in silicon nitride by acoustic microscopy United Kingdom Atomic Energy Authority, Harwell, A E R E - R 13196, 22 pp. (Dec. 1988) This paper reports the application of acoustic microscopy to the detection of critical defects in a test block and in a finished ball bearing component, both of which were manufactured from the same silicon nitride material. The data demonstrate the importance of choosing a sufficiently high frequency in order to detect shallow surface-opening cracks. Thus defects that could not be detected or resolved at 250 MHz, were resolvable at 400 MHZ. 40286
Issouckis, M.
Scanning acoustic microscopy - principles and applications Metals and Materials, Vol. 5, No. 2, pp. 63-67 (Feb. 1989) Acoustic microscopy is a relatively new technique which offers materials scientists the ability to image surface or sub-surface structures according to variations in their elastic properties, and its applications encompass a wide range of materials. This article describes the basic principles of acoustic microscopy and its use in materials science in the study of ceramics, polymers, composites, metals and semiconductor materials. The author considers the imaging capabilities of the technique and describes its quantitative aspects and use in material characterisation. 40241
Khandelwal, P.K.
Nondestructive evaluation (NDE) of structural ceramics by photoaeoustic microscopy General Motors Corp., Indianapolis, IN (United States) N88-23884, 7 pp. (May 1986) Photoacoustic microscopy (PAM) was utilized to detect surface and subsurface defects in structural ceramic materials. A computerized PAM data acquisition, color imaging and analysis system was developed and used. Subsurface simulated cylindrical holes can be detected to about 1 mm below the interrogating surface. Simulated tight surface cracks of 96 microns length and 48 microns depth can be detected in these materials under optimum conditions. 40240
Vary, A.
Nondestructive evaluation of structural ceramics National Aeronautics and Space Administration, Cleveland, OH. Lewis Research Center (United States) N88-23876, 12 pp. (May 1986) Research on nondestructive evaluation (NDE) of structural ceramics for heat engine applications is reviewed. Microfocus radiography and scanning laser acoustic microscopy are the NDE techniques highlighted. The techniques were applied to research samples of sintered silicon nitride and silicon carbide in the form of modulus-of-rupture (MOR) bars. The strength and limitations of the aforementioned techniques are given in terms of probability of detection for voids in green and sintered MOR bars. Voids for this purpose were introduced by seeding green ceramic bars and characterizing each void in terms of its size,
NDT International February 1990
shape, location, and nature before and after sintering. The effects of materials density, microstructure, surface finish, thickness, void depth, and size characteristics on detectability are summarized. 40194
Ringermacher, H.L; Bak, M.
Thermomechanical contrast mechanism in thermoacoustic imaging for NDE Review of Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States), 22-26 Jun. 1987. Vol. 7A, pp. 239-244. Edited by D . D . T h o m p s o n and D.E.Chimenti, Plenum Press, 1988. An unusual thermoacoustic image has been observed using Scanning Electron Microscopy (SEAM), of a prepared subsurface groove in a calibration specimen. An exceptionally clear thermoacoustic image was obtained of the subsurface portion of the groove even in the region where the groove depth exceeded 25 thermal diffusion lengths of the thermal wave at the operating modulation frequency. This was clearly not a thermal wave image. At that time is was proposed that this was a new contrast mechanism which was essentially an image of the local compliance of the plate- that is, a thermomechanicai image. In the present work, the thermomechanical contrast mechanism is verified using a finite element analysis employing a purely thermomechanical formulation. The analysis is time independent and also independent of the temperature distribution of the ingoing thermal wave. A single thermal element constant energy loading is assumed to produce the specimen's mechanical response. 40192
Favro, L.D.; Shepard, S.M.; Kuo, P.K.; Thomas, R.L.
Sound producing mechanisms in thermoaconstic microscopes Review of Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States), 22-26 Jun. 1987. Voi. 7A, pp. 225-229. Edited by D . D . T h o m p s o n and D.E.Chimenti, Plenum Press, 1988. Thermoacoustic microscopes generate sound in a solid by using a focussed laser or particle beam to deposit energy and momentum in a localized region just beneath the samples surface. These beams may be either pulsed or periodically modulated and generate sound either through thermal expansion effects or through direct momentum transfer to the lattice. In general both longitudinal and transverse (as well as surface) sound waves and thermal waves are generated. For purposes of microscopy, sources which are much more nearly approximated by a point are used, and the operation is usually in the frequency domain, i.e., with a periodically modulated source. Therefore a model is needed of the sound generation for a periodic point source. In this paper an exact solution to the thermoelastic equations with such a source is described. Although all of the details are not discussed in this paper, the solution, being exact, describes all of the thermal and elastic wave modes, in the bulk and on the surface. 40075
Fanton, J.T.; Chou, C.-H.; Khuri-Yakub, B.T.; Kino, G.S.
Evaluation of solder bonds in a silicon flip chip device Review of Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States), 22-26 Jun. 1987. Vol. 7B, pp. 1195-1202. Edited by D.D. T h o m p s o n and D.E. Chimenti, Plenum Press, 1988. Recently two nondestructive testing techniques were adapted for the evaluation of electrical connections between a silicon device wafer and an inverted silicon interconnect chip. A focused acoustic microscope was used to check the mechanical quality of the connections, and a photothermal probe was used to measure their electrical conductivity. With the combination of these two techniques, differences can be observed between good bonds, partial disbonds, and complete open circuits. The type of disbond can also be determined. 40074
Addison, R.C. Jr.; Marshal[, D.B.
Correlation of thin-film bond compliance and bond fracture resistance Review of Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States), 22-26 Jun. 1987. Vol. 7B, pp. 1185-1194. Edited by D.D. Thompson and D.E. Chimenti, Plenum Press, 1988. The integrity of the interracial bond between a coating and its substrate is of primary importance for any application. Scanning acoustic microscopy (SAM) provides a method for making localized measurements of film disbonds and film bond compliance based on the changes in the surface acoustic wave velocity in the layered medium, The results of these measurements for chrome/gold and gold films on glass substrates are summarized. An experiment to determine if this correlation exists for chrome/gold and gold films on sapphire substrates is described. Results of such an experiment would provide an empirical correlation between surface acoustic wave velocity measurements and the fracture energy of the film. The results of an experiment to measure the fracture energy of the interfacial bond between a gold film and the sapphire substrate are described.
40064 Thomas, G.; Odegard, B.C. Inspecting advanced composite materials at ultrasonic frequencies from 2 megahertz to 2 gigahertz Review of Progress in Quantitative Nondestructive Evaluation, Williamsburg, Virginia (United States), 22-26 Jun. 1987. Vol. 7B, pp. 1003-1010. Edited by D.D. T h o m p s o n and D.E. Chimenti, Plenum Press, 1988. Ultrasonic nondestructive evaluation is an effective method of evaluating various types of composite materials for defects. This paper discusses the role ultrasonic nondestructive evaluation performed in studying the impact tolerance
41