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incident pulse shaping

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Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006469
EISBN: 978-1-62708-190-0
... intervals of time. If the pulses encounter a reflecting surface, some or all of the energy is reflected. The proportion of energy that is reflected is highly dependent on the size of the reflecting surface in relation to the size of the incident ultrasonic beam. The direction of the reflected beam (echo...
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006470
EISBN: 978-1-62708-190-0
..., surface waves, and lamb waves. The article reviews the major variables in ultrasonic inspection, including frequency, acoustic impedance, angle of incidence, and beam intensity. It discusses the attenuation of ultrasonic beams and provides information on the pulse-echo and transmission methods for...
Series: ASM Handbook
Volume: 10
Publisher: ASM International
Published: 15 December 2019
DOI: 10.31399/asm.hb.v10.a0006667
EISBN: 978-1-62708-213-6
... through bombarding a heavy metal target of, for example, tungsten or mercury, with a high-energy proton beam (several hundreds of mega-electron volt to giga-electron volt). The proton beam typically reaches the target in carefully shaped and timed discrete bunches or pulses. Each impact starts a cascade...
Book Chapter

By S.L. Rohde
Series: ASM Handbook
Volume: 5
Publisher: ASM International
Published: 01 January 1994
DOI: 10.31399/asm.hb.v05.a0001288
EISBN: 978-1-62708-170-2
... ejected from a surface by momentum transfer from an energetic bombarding species of atomic/molecular size. It uses a glow discharge or an ion beam to generate a flux of ions incident on the target surface. This article provides an overview of the advantages and limitations of sputter deposition. It...
Series: ASM Handbook
Volume: 5
Publisher: ASM International
Published: 01 January 1994
DOI: 10.31399/asm.hb.v05.a0001294
EISBN: 978-1-62708-170-2
... Abstract This article presents a general description of pulsed-laser deposition. It describes the components of pulsed-laser deposition equipment. The article also discusses the effects of angular distribution of materials. Finally, the article reviews the characteristics of high-temperature...
Book Chapter

Series: ASM Desk Editions
Publisher: ASM International
Published: 01 December 1998
DOI: 10.31399/asm.hb.mhde2.a0003236
EISBN: 978-1-62708-199-3
... surface with respect to the incident beam. Reflected energy is monitored; both the amount of energy reflected in a specific direction and the time delay between transmission of the initial pulse and receipt of the echo are measured. Interpretation of pulse-echo data is relatively...
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006464
EISBN: 978-1-62708-190-0
... flash pulse or a longer step or temporally modulated sequence (e.g., a square wave or sinusoid). Optical excitation is widely used for SET because it is relatively easy to apply over a large area, and the sources are compact and cost-effective. Lamps are usually housed in reflectors to shape the spatial...
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006473
EISBN: 978-1-62708-190-0
... reviews the determination of area-amplitude and distance-amplitude curves of a straight-beam pulse-echo ultrasonic inspection system. The article discusses the three principal conventional manual ultrasonic sizing techniques: 6 dB drop technique, maximum-amplitude technique, and 20 dB drop technique. It...
Book Chapter

Series: ASM Desk Editions
Publisher: ASM International
Published: 01 December 1998
DOI: 10.31399/asm.hb.mhde2.a0003240
EISBN: 978-1-62708-199-3
... Abstract Holography is basically a two-step process for creating a whole three dimensional image of a diffusely reflecting object having some arbitrary shape. This article discusses the advantages, disadvantages and applications of using the optical holography method in nondestructive...
Series: ASM Handbook
Volume: 10
Publisher: ASM International
Published: 15 December 2019
DOI: 10.31399/asm.hb.v10.a0006677
EISBN: 978-1-62708-213-6
... the essential components, and explains their function only to the extent that it helps the operator obtain the desired results. An explanation of how the components of ion optical column shape and steer the ion beam to the desired target locations is then provided. The article also reviews the many...
Series: ASM Handbook
Volume: 23
Publisher: ASM International
Published: 01 June 2012
DOI: 10.31399/asm.hb.v23.a0005680
EISBN: 978-1-62708-198-6
... and stimulated emission. The former describes a one-to-one ratio of photon emission to electron relaxation. In stimulated emission, the incident photon collides with another energized atom, causing an emission of another photon of equal frequency, phase polarization, and direction of travel. During...
Book Chapter

Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006474
EISBN: 978-1-62708-190-0
... plane shaped to the ideal surface, with the central ray kept normal to the surface. In liquid-surface systems ( Fig. 8 ), two separate ultrasonic transducers supply the object beam and reference beam, which are both usually pulsed. The two transducers and the test object are immersed in a water-filled...
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006475
EISBN: 978-1-62708-190-0
... boundaries and interact with the molecules that constitute the material. For example, it was found that the best source for the thickness and voids in radomes was the microwaves generated within the radomes. Both continuous and pulsed incident waves were used in these tests, and either reflected or...
Series: ASM Handbook
Volume: 5
Publisher: ASM International
Published: 01 January 1994
DOI: 10.31399/asm.hb.v05.a0001233
EISBN: 978-1-62708-170-2
... current dissolution, hence the uniformity of metal dissolution and the shape profiles during throughmask EMM. A new finishing method has been developed using an electrochemical finishing machine ( Ref 8 ). This method enables the operator to set the timing of a switchover to pulses having a high current...
Series: ASM Desk Editions
Publisher: ASM International
Published: 01 December 1998
DOI: 10.31399/asm.hb.mhde2.a0003194
EISBN: 978-1-62708-199-3
...; high temperature alloy forgings; odd shaped holes and cavities; jet engine blade airfoils; small deep holes; jet engine blade cooling holes; deburring; face turning of disks; tungsten carbide machining; etching of numbers and letters in hard steels; selective machining of one material from another...
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006471
EISBN: 978-1-62708-190-0
... piezoelectric implies, an electrical charge is developed by the crystal when pressure is applied to it. Conversely, when an electrical field is applied, the crystal mechanically deforms (changes shape). Piezoelectric crystals exhibit various deformation modes; thickness expansion is the principal mode used in...
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006460
EISBN: 978-1-62708-190-0
... penetration of 5 to 10 nm for metals becomes comparable to the acoustic wavelength). When penetration increases, the displacement pulse starts to increase and its shape is found to follow proportionally that of the laser pulse. With further increase of light penetration, when the penetration depth becomes...
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006478
EISBN: 978-1-62708-190-0
... material. If the heating laser pulse duration is short (10 to 100 ns), then the expansion will be in the frequency of ultrasound (1 to 10 MHz). The important feature is that the ultrasound will propagate perpendicular to the surface, independent of the laser angle of incidence. This allows generation of...
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006461
EISBN: 978-1-62708-190-0
... Fig. 7 . The reflected amplitude of the Rayleigh wave from the crack will be different for the oblique and normal incidence cases. In this case, the crack length can be characterized by performing a B-scan (single-axis scan) in pulse-echo mode. The drop in amplitude will represent the crack length...
Series: ASM Handbook
Volume: 23
Publisher: ASM International
Published: 01 June 2012
DOI: 10.31399/asm.hb.v23.a0005685
EISBN: 978-1-62708-198-6
... images combined using an extended depth-of-field technique to allow the surfaces of interest to be in focus in a single image. Sample size, shape, and condition requirements depend on the configuration of the microscope. Low-magnification stereomicroscopes are small and have a long focal length (up...