Surface roughness evaluation via ultrasonic scanning

Despite extensive applications of ultrasonic waves to various nondestructive testing and evaluation of materials, scattering of focused ultrasonic waves due to surface roughness has not been fully investigated. This paper presents an analytical and experimental evaluation of surface roughness measurement using focused ultrasonic beams. The characteristics of focused ultrasonic waves are analyzed by using the impulse response method with a sine-modulated Gaussian pulse as source. First, the beam profile in the focal plane of the focused ultrasonic transducer is analyzed both numerically and experimentally. Second, peak amplitude distribution and reflected waveforms from a flat surface with various incident angles are analytically generated and compared with experimental results. Then, the peak amplitudes of the ultrasonic waves reflected from cusped surfaces which are easily found among machined surfaces are analyzed and compared with experimental data for the first time. The analysis shows good agreement between analytical and experimental results. The excellent correlation between the measurements using a profilometer and the proposed ultrasonic system demonstrates a good potential for surface roughness measurement by ultrasonic sensing.<<ETX>>

[1]  F. Luk,et al.  Measurement of surface roughness by a machine vision system , 1989 .

[2]  Paul Vanherck,et al.  Assessment of surface typology analysis techniques , 1979 .

[3]  T. Tarnoczy,et al.  Sound focussing lenses and waveguides , 1965 .

[4]  P. F. Smith,et al.  Enhanced surface parametrization using maximum entropy signal processing of ultrasonic pulses , 1991 .

[5]  T. Vorburger,et al.  Optical techniques for on-line measurement of surface topography , 1981 .

[6]  M Arditi,et al.  Transient fields of concave annular arrays. , 1981, Ultrasonic imaging.

[7]  Ian Sherrington,et al.  The significance of surface topography in engineering , 1986 .

[8]  Ian Sherrington,et al.  Modern measurement techniques in surface metrology: part I; stylus instruments, electron microscopy and non-optical comparators , 1988 .

[9]  The Possibility of Assigning a Signature to Rough Surfaces Using Ultrasonic Backscattering Diagrams , 1976, IEEE Transactions on Sonics and Ultrasonics.

[10]  A. J. Hayman,et al.  Observations of the propagation of very short ultrasonic pulses and their reflection by small targets , 1978 .

[11]  P. King,et al.  Scanning capacitance microscopy , 1988 .

[12]  Mauri Luukkala,et al.  The impulse response and pressure nearfield of a curved ultrasonic radiator , 1976 .

[13]  J. Baboux,et al.  The transient field of a planar ultrasonic transducer coupled to a lens: Experiments and simulations , 1990 .

[14]  Mauri Luukkala,et al.  Sound pressure near the focal area of an ultrasonic lens , 1976 .

[15]  J. Cardoso,et al.  Diffraction Effects in Pulse-Echo Measurement , 1984, IEEE Transactions on Sonics and Ultrasonics.

[16]  K. Mitsui.  In-proces sensors for surface roughness and their applications , 1986 .

[17]  P. F. Smith,et al.  The determination of surface topology by the signal processing of ultrasonic pulses , 1988 .

[18]  J. C. Baboux,et al.  Theoretical and experimental study of the field radiated by ultrasonic focussed transducers , 1991 .

[19]  J. C. Baboux,et al.  Experimental determination of the impulse response of axisymmetric focused ultrasonic transducers , 1990 .

[20]  D. G. Eitzen,et al.  Ultrasonic Sensor For Measuring Surface Roughness , 1989, Other Conferences.

[21]  E. S. Furgason,et al.  Beam profiling using correlation systems , 1980 .

[22]  Albert Freedman,et al.  Sound Field of Plane or Gently Curved Pulsed Radiators , 1970 .

[23]  Ian Sherrington,et al.  Modern measurement techniques in surface metrology: part II; optical instruments , 1988 .

[24]  P. F. Smith,et al.  The performance of the maximum entropy method: deconvolution and the frequency content of data , 1989 .

[25]  G. Quentin,et al.  Experimental Results on the Scattering of Ultrasound by Randomly or Periodically Rough Surfaces in the Frequency Range 2 to 25 MHz , 1975 .

[26]  V. Ruisi,et al.  Computer vision profilometer: equipment and evaluation of measurements , 1991 .

[27]  Joseph L. Garbini,et al.  Surface Profile Measurement During Turning Using Fringe-Field Capacitive Profilometry , 1990 .

[28]  E. G. Thwaite,et al.  Measurement and control of surface finish in manufacture , 1984 .

[29]  H. M. Ryan,et al.  Surface micrometrology using ultrasound , 1990, IEEE Symposium on Ultrasonics.

[30]  David J. Whitehouse.  Surface metrology instrumentation , 1987 .

[31]  H. O'neil.  Theory of Focusing Radiators , 1949 .

[32]  A. M. Hamouda.  A precise pneumatic co-axial jet gauging system for surface roughness measurements , 1979 .