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Material characterization by acoustic line-focus beam
13- 14 Nov. 1984. pp. 193-205. N A S A C o n f e r e n c e P u b l i c a t i o n 2383 (1986) One potential approach to the quantitative acquisition of discriminatory information that can isolate a single structural state is pattern recognition. The pattern recognition characterizations of micromechanical and morphological materials states via analytical quantitative ultrasonics are outlined in this paper. The concepts, terminology, and techniques of statistical pattern recognition are reviewed. Feature extraction and classification and states of the structure can be determined via a program of ultrasonic data generation. 36803
Generazio, E.R.
Ultrasonic treatment
verification
of mierostructural
changes
due
to heat
A n a l y t i c a l U l t r a s o n i c s in M a t e r i a l s R e s e a r c h a n d Testing. P r o c e e d i n g s of a c o n f e r e n c e , N A S A L e w i s R e s e a r c h C e n t e r , O h i o ( U n i t e d States), 13- 14 Nov. 1984. pp. 207-217. N A S A C o n f e r e n c e P u b l i c a t i o n 2383 (1986) Ultrasonic attenuation was measured for polycrystalline samples of nickel and copper with various grain-size distributions produced by heat treatment. Attenuation as a function of frequency was determined for a sample having a known mean grain diameter. Once this function was determined, it could be scaled to determine the mean grain size of other samples of the same material with different mean grain diameters. These results were obtained by using broadband pulse-echo ultrasound in the 25- to 100-MHz frequency range. The results suggest an ultrasonic, nondestructive approach for verifying heat treatment of metals. 36802
Serabian, S.
Ultrasonic material property determinations A n a l y t i c a l U l t r a s o n i c s in M a t e r i a l s R e s e a r c h a n d Testing. P r o c e e d i n g s of a c o n f e r e n c e , N A S A L e w i s R e s e a r c h C e n t e r , O h i o ( U n i t e d States), 13- 14 Nov. 1984. pp. 219-232. N A S A C o n f e r e n c e P u b l i c a t i o n 2383 (1986) The use and potential offered by ultrasonic velocity and attenuation measurements to determine and/or monitor material properties is explored. The basis for such unique measurements along with examples of materials from a variety of industries will be presented. 36797 Various A n a l y t i c a l U l t r a s o n i c s in M a t e r i a l s Research and Testing A n a l y t i c a l U l t r a s o n i c s in M a t e r i a l s R e s e a r c h a n d Testing. P r o c e e d i n g s of a c o n f e r e n c e , N A S A L e w i s R e s e a r c h C e n t e r , O h i o ( U n i t e d States), 13- 14 Nov. 1984. N A S A C o n f e r e n c e P u b l i c a t i o n 2382, 364 pp. (1986) The Analytical Ultrasonics in Materials Research and Testing Conference was held at the NASA Lewis Research Center on November 13-14, 1984. This proceedings includes 21 papers dealing with various aspects of analytical ultrasonics. Analytical ultrasonics may be defined as a branch of nondestructive evaluation concerned with measurement of microstructural factors that govern mechanical properties and dynamic response of structural materials. This definition goes beyond flaw detection, flaw imaging, and defect characterization. Analytical ultrasonics includes the assessment of material environments in which the flaws reside. This proceedings presents recent results and advancements in analytical ultrasonics for application to materials research and testing. (Individual papers have been abstracted separately). 36796
Vary, A.; Kautz, H.E.
Transfer function concept for ultrasonic characterization of material microstructures A n a l y t i c a l U l t r a s o n i c s in M a t e r i a l s R e s e a r c h a n d Testing. P r o c e e d i n g s of a c o n f e r e n c e , N A S A L e w i s R e s e a r c h C e n t e r , O h i o ( U n i t e d States), 13- 14 Nov. 1984. pp. 257-297. N A S A C o n f e r e n c e Publication 2383 (1986) The approach given herein depends on treating material microstructures as elastomechanical filters that have analytically definable transfer functions. These transfer functions can be defined in terms of the frequency dependence of the ultrasonic attenuation coefficient (Vary, 1980b, 1984). The transfer function concept provides a basis for synthesizing expressions that characterize polycrystalline materials relative to microstructural factors such as mean grain size, grain-size distribution functions, and grain boundary energy transmission. Although our approach is nonrigorous, it leads to a rational basis for combining the previously mentioned diverse and fragmented equations for ultrasonic attenuation coefficients. 36784
Telschow, K.L.; Flinn, J.E.
Ultrasonic backscatter and attenuation measurements for microstructure characterization: application to consolidated rapidly solidified type 304 stainless steel powder I d a h o N a t i o n a l E n g i n e e r i n g L a b o r a t o r y , I d a h o ( U n i t e d States), E G G - S C M - 7198, DE86-014917, 41 pp. (Mar. 1986) The results of this study show that ultrasonic measurements of attenuation and baekscatter energy can be correlated with microstructural features in the RSP consolidated materials utilized. In particular, attenuation and backscatter energy were shown to be consistent with each other and to yield approximately the same microstructural information. This is important because the backscatter technique can be implemented more easily than the attenuation measurement as it requires access to only one surface of the sample under study. More information is available in the backscatter signals, but as yet is not understood well enough to be utilized. The high degree of correlation between the
31 0
microstructural examinations and the ultrasonic measurements allows the latter to be of use in evaluating the effectiveness of various consolidation methods. 36781
Thompson, R.B.; Lee, S.S.; Smith, J.F.
Relative anisotropies of plane waves and guided modes in thin orthorhombic plates: implication for texture characterization U l t r a s o n i c s , Vol. 25, No. 3, pp. 133-137 ( M a y 1987) The angular dependences of the long wavelength velocities of S/sub o / a n d SH/sub o/modes of orthorhombic (orthotropic) plates are compared to those of the velocities of corresponding plane waves. To first order in the anisotropy, many of the phenomena are as expected. The absolute velocities and anisotropy of the SH/sub o/plate modes are identical to those for plane SH waves and the absolute velocities of the S/sub o/modes propagating along symmetry axes are reduced from the longitudinal plane wave velocities by an amount explained by the change from the plane strain to the plane stress condition. However, for certain classes of materials such as metal polycrystals, the anisotropy of the S/sub o/mode can be substantially different from that of the longitudinal plane waves. This effect is explained through an expansion of the crystallite orientation distribution function in terms of generalized spherical harmonics. Implications of the results for the ultrasonic measurement of preferred grain orientation (texture) in polycrystals is indicated. 36776
Vary,A.
Ultrasonic nondestructive evaluation, microstructure, and mechanical property interrelations N a t i o n a l A e r o n a u t i c s a n d Space A d m i n i s t r a t i o n , C l e v e l a n d , O h i o ( U n i t e d States), N85-10371, 30 pp. (Oct. 1984) Ultrasonic techniques for mechanical property characterizations are reviewed and conceptual models are advanced for explaining and interpreting the empirically based results. 36753
Kushibiki, J.; Matsumoto, Y.; Chubachi, N.
Material characterization by acoustic line-focus beam A c o u s t i c a l I m a g i n g , Vol. 13. P r o c e e d i n g s of the T h i r t e e n t h International Symposium on Acoustical Imaging, Minneapolis (United States), 26-28 Oct. 1983. pp. 193-202. E d i t e d b y M. K a v e h a n d R.K. M u e l l e r . P l e n u m Press, 605 pp. (1984) In this paper, we propose a novel method of material characterization of determining both the velocity and the attenuation of leaky waves directly from V(z) curves obtained by the acoustic line-focus beam microscope. In this method, a simple model is developed to represent transducer output V(z), which is approximately formed by a combination of ray and field theories. Experiments are demonstrated for a fused quartz sample using an acoustic line-focus-beam sapphire lens of 1.0 mm radius at 226.3 MHz. This characterization method is applied to quantitative estimation of two Mn-Zn ferrite samples with different grain size, and the results are compared with acoustic imaging information observed by the reflection type scanning acoustic microscope at a frequency of 440 MHz. 36749
Lee, S.S.
Inference of stress and texture from the velocities of ultrasonic plate modes D i s s e r t a t i o n A b s t r a c t s I n t e r n a t i o n a l , Vol. 47, No. 8, p. 3479 (Feb. 1987) An ultrasonic approach is proposed to independently characterize stress and texture in rolled metal plate. The approach is based on the theory for the angular dependence of the ultrasonic wave velocity in a symmetry plane of an orthorhombic, stressed material. The theory for the angular dependence of the velocities reveals terms with two-fold, four-fold, and six-fold symmetry, which are utilized in the separation of the stress and texture contributions. 36746
Ogilvy, J.A.
The influence of austenitie weld geometry and manufacture u l t r a s o n i c inspection of welded joints
on
British J o u r n a l of N o n d e s t r u c t i v e Testing, Vol. 29, No. 3, pp. 147-156 ( M a y 1987) A theoretical ray-tracing model to investigate how ultrasonic energy travels through austenitic weld metal is used. Bending of ray paths, due to the inhomogeneous nature of the metal, unexpected directions of beam travel due to the anisotropy, and changes in ray amplitudes due to grain refraction, is observed. Some common weld structures are investigated to see how favourable these welds are to ultrasonic inspection. This study shows that the welds most suited to predictable ultrasonic inspection are not necessarily those with a small volume of weld metal. It is primarily the form of the grain structure which determines the intrinsic ultrasonic inspectability of a weld. The weld ideal for ultrasonic inspection has a grain structure which is as close to homogeneous as possible. The importance of understanding the relationships between welding technique and grain structure, in order to ensure that commonly manufactured welds possess favourable grain structures, is briefly discussed. 36565
Sayers, C..M.; Proudfoot, G.G.
Angular dependence of the ultrasonic SH wave velocity in rolled m e t a l sheets United Kingdom Atomic Energy Authority, Harwell, AERE-R12077, 29pp. (Jan. 1986) The ultrasonic SH wave technique is a promising method for separating out the effects of texture and stress on the ultrasonic velocity, and allows the texture and stress to be determined separately. Allen and Langman have reported
NDT International October 1989
Generazio, E.R.
Ultrasonic treatment
verification
of mierostructural
changes
due
to heat
A n a l y t i c a l U l t r a s o n i c s in M a t e r i a l s R e s e a r c h a n d Testing. P r o c e e d i n g s of a c o n f e r e n c e , N A S A L e w i s R e s e a r c h C e n t e r , O h i o ( U n i t e d States), 13- 14 Nov. 1984. pp. 207-217. N A S A C o n f e r e n c e P u b l i c a t i o n 2383 (1986) Ultrasonic attenuation was measured for polycrystalline samples of nickel and copper with various grain-size distributions produced by heat treatment. Attenuation as a function of frequency was determined for a sample having a known mean grain diameter. Once this function was determined, it could be scaled to determine the mean grain size of other samples of the same material with different mean grain diameters. These results were obtained by using broadband pulse-echo ultrasound in the 25- to 100-MHz frequency range. The results suggest an ultrasonic, nondestructive approach for verifying heat treatment of metals. 36802
Serabian, S.
Ultrasonic material property determinations A n a l y t i c a l U l t r a s o n i c s in M a t e r i a l s R e s e a r c h a n d Testing. P r o c e e d i n g s of a c o n f e r e n c e , N A S A L e w i s R e s e a r c h C e n t e r , O h i o ( U n i t e d States), 13- 14 Nov. 1984. pp. 219-232. N A S A C o n f e r e n c e P u b l i c a t i o n 2383 (1986) The use and potential offered by ultrasonic velocity and attenuation measurements to determine and/or monitor material properties is explored. The basis for such unique measurements along with examples of materials from a variety of industries will be presented. 36797 Various A n a l y t i c a l U l t r a s o n i c s in M a t e r i a l s Research and Testing A n a l y t i c a l U l t r a s o n i c s in M a t e r i a l s R e s e a r c h a n d Testing. P r o c e e d i n g s of a c o n f e r e n c e , N A S A L e w i s R e s e a r c h C e n t e r , O h i o ( U n i t e d States), 13- 14 Nov. 1984. N A S A C o n f e r e n c e P u b l i c a t i o n 2382, 364 pp. (1986) The Analytical Ultrasonics in Materials Research and Testing Conference was held at the NASA Lewis Research Center on November 13-14, 1984. This proceedings includes 21 papers dealing with various aspects of analytical ultrasonics. Analytical ultrasonics may be defined as a branch of nondestructive evaluation concerned with measurement of microstructural factors that govern mechanical properties and dynamic response of structural materials. This definition goes beyond flaw detection, flaw imaging, and defect characterization. Analytical ultrasonics includes the assessment of material environments in which the flaws reside. This proceedings presents recent results and advancements in analytical ultrasonics for application to materials research and testing. (Individual papers have been abstracted separately). 36796
Vary, A.; Kautz, H.E.
Transfer function concept for ultrasonic characterization of material microstructures A n a l y t i c a l U l t r a s o n i c s in M a t e r i a l s R e s e a r c h a n d Testing. P r o c e e d i n g s of a c o n f e r e n c e , N A S A L e w i s R e s e a r c h C e n t e r , O h i o ( U n i t e d States), 13- 14 Nov. 1984. pp. 257-297. N A S A C o n f e r e n c e Publication 2383 (1986) The approach given herein depends on treating material microstructures as elastomechanical filters that have analytically definable transfer functions. These transfer functions can be defined in terms of the frequency dependence of the ultrasonic attenuation coefficient (Vary, 1980b, 1984). The transfer function concept provides a basis for synthesizing expressions that characterize polycrystalline materials relative to microstructural factors such as mean grain size, grain-size distribution functions, and grain boundary energy transmission. Although our approach is nonrigorous, it leads to a rational basis for combining the previously mentioned diverse and fragmented equations for ultrasonic attenuation coefficients. 36784
Telschow, K.L.; Flinn, J.E.
Ultrasonic backscatter and attenuation measurements for microstructure characterization: application to consolidated rapidly solidified type 304 stainless steel powder I d a h o N a t i o n a l E n g i n e e r i n g L a b o r a t o r y , I d a h o ( U n i t e d States), E G G - S C M - 7198, DE86-014917, 41 pp. (Mar. 1986) The results of this study show that ultrasonic measurements of attenuation and baekscatter energy can be correlated with microstructural features in the RSP consolidated materials utilized. In particular, attenuation and backscatter energy were shown to be consistent with each other and to yield approximately the same microstructural information. This is important because the backscatter technique can be implemented more easily than the attenuation measurement as it requires access to only one surface of the sample under study. More information is available in the backscatter signals, but as yet is not understood well enough to be utilized. The high degree of correlation between the
31 0
microstructural examinations and the ultrasonic measurements allows the latter to be of use in evaluating the effectiveness of various consolidation methods. 36781
Thompson, R.B.; Lee, S.S.; Smith, J.F.
Relative anisotropies of plane waves and guided modes in thin orthorhombic plates: implication for texture characterization U l t r a s o n i c s , Vol. 25, No. 3, pp. 133-137 ( M a y 1987) The angular dependences of the long wavelength velocities of S/sub o / a n d SH/sub o/modes of orthorhombic (orthotropic) plates are compared to those of the velocities of corresponding plane waves. To first order in the anisotropy, many of the phenomena are as expected. The absolute velocities and anisotropy of the SH/sub o/plate modes are identical to those for plane SH waves and the absolute velocities of the S/sub o/modes propagating along symmetry axes are reduced from the longitudinal plane wave velocities by an amount explained by the change from the plane strain to the plane stress condition. However, for certain classes of materials such as metal polycrystals, the anisotropy of the S/sub o/mode can be substantially different from that of the longitudinal plane waves. This effect is explained through an expansion of the crystallite orientation distribution function in terms of generalized spherical harmonics. Implications of the results for the ultrasonic measurement of preferred grain orientation (texture) in polycrystals is indicated. 36776
Vary,A.
Ultrasonic nondestructive evaluation, microstructure, and mechanical property interrelations N a t i o n a l A e r o n a u t i c s a n d Space A d m i n i s t r a t i o n , C l e v e l a n d , O h i o ( U n i t e d States), N85-10371, 30 pp. (Oct. 1984) Ultrasonic techniques for mechanical property characterizations are reviewed and conceptual models are advanced for explaining and interpreting the empirically based results. 36753
Kushibiki, J.; Matsumoto, Y.; Chubachi, N.
Material characterization by acoustic line-focus beam A c o u s t i c a l I m a g i n g , Vol. 13. P r o c e e d i n g s of the T h i r t e e n t h International Symposium on Acoustical Imaging, Minneapolis (United States), 26-28 Oct. 1983. pp. 193-202. E d i t e d b y M. K a v e h a n d R.K. M u e l l e r . P l e n u m Press, 605 pp. (1984) In this paper, we propose a novel method of material characterization of determining both the velocity and the attenuation of leaky waves directly from V(z) curves obtained by the acoustic line-focus beam microscope. In this method, a simple model is developed to represent transducer output V(z), which is approximately formed by a combination of ray and field theories. Experiments are demonstrated for a fused quartz sample using an acoustic line-focus-beam sapphire lens of 1.0 mm radius at 226.3 MHz. This characterization method is applied to quantitative estimation of two Mn-Zn ferrite samples with different grain size, and the results are compared with acoustic imaging information observed by the reflection type scanning acoustic microscope at a frequency of 440 MHz. 36749
Lee, S.S.
Inference of stress and texture from the velocities of ultrasonic plate modes D i s s e r t a t i o n A b s t r a c t s I n t e r n a t i o n a l , Vol. 47, No. 8, p. 3479 (Feb. 1987) An ultrasonic approach is proposed to independently characterize stress and texture in rolled metal plate. The approach is based on the theory for the angular dependence of the ultrasonic wave velocity in a symmetry plane of an orthorhombic, stressed material. The theory for the angular dependence of the velocities reveals terms with two-fold, four-fold, and six-fold symmetry, which are utilized in the separation of the stress and texture contributions. 36746
Ogilvy, J.A.
The influence of austenitie weld geometry and manufacture u l t r a s o n i c inspection of welded joints
on
British J o u r n a l of N o n d e s t r u c t i v e Testing, Vol. 29, No. 3, pp. 147-156 ( M a y 1987) A theoretical ray-tracing model to investigate how ultrasonic energy travels through austenitic weld metal is used. Bending of ray paths, due to the inhomogeneous nature of the metal, unexpected directions of beam travel due to the anisotropy, and changes in ray amplitudes due to grain refraction, is observed. Some common weld structures are investigated to see how favourable these welds are to ultrasonic inspection. This study shows that the welds most suited to predictable ultrasonic inspection are not necessarily those with a small volume of weld metal. It is primarily the form of the grain structure which determines the intrinsic ultrasonic inspectability of a weld. The weld ideal for ultrasonic inspection has a grain structure which is as close to homogeneous as possible. The importance of understanding the relationships between welding technique and grain structure, in order to ensure that commonly manufactured welds possess favourable grain structures, is briefly discussed. 36565
Sayers, C..M.; Proudfoot, G.G.
Angular dependence of the ultrasonic SH wave velocity in rolled m e t a l sheets United Kingdom Atomic Energy Authority, Harwell, AERE-R12077, 29pp. (Jan. 1986) The ultrasonic SH wave technique is a promising method for separating out the effects of texture and stress on the ultrasonic velocity, and allows the texture and stress to be determined separately. Allen and Langman have reported
NDT International October 1989