Ultrasonic Interface Waves

S. I. Rokhlin, M. Hefets, and M. Rosen, An ultrasonic interface-wave method for predicting the strength of adhesive bonds, J. Appl. Phys. 52, 2847 (1981). 

Analysis of Metal-Polymer Boundaries using Ultrasonic Interface Waves... 

Fig. 3.7.1. Experimental arrangement for studying the reflexion of ultrasonic shear waves at a solid-nematic interface.

The viscosity coefficients may also be determined by studying the reflexion of ultrasonic shear waves at a solid-nematic interface. The technique was developed by Martinoty and Candau. A thin film of a nematic liquid crystal is taken on the surface of a fused quartz rod with obliquely cut ends (fig. 3.7.1). A quartz crystal bonded to one of the ends generates a transverse wave. At the solid-nematic interface there is a transmitted wave, which is rapidly attenuated, and a reflected wave which is received at the other end by a second quartz crystal. The reflexion coefficient, obtained by measuring the amplitudes of reflexion with and without the nematic sample, directly yields the effective coefficient of viscosity. 

Figure 14 Ultrasonic shear waves at the interface between two media (r, > i .).

Scala C.M. and P.A., Doyle, Ultrasonic leaky interface waves for composite-metal adhesive bond characterization. Journal of Nondestructive Evaluation, 14(2), 1995. 

G. C. Knollman and J. J. Hartog, Shear modulus gradients in adhesive interfaces as determined by means of ultrasonic Rayleigh waves, J. Appl. Phys. 53, Part I, 1516 (1982). 

Use of Ultrasonic Shear Waves for the Study of Liquid Interfaces... 

This chapter is concerned with the study of liquid interfaces. Liquid interfaces would mostly mean droplets, vesicles, or bubbles. Bubbles and "nanobubbles," in particular, have been studied extensively in the context of slippage and the long-range hydrophobic attraction.Today they are studied by numerous groups independently of these specific applications. This chapter only covers a rather narrow subtopic of this research field. We show in the second part that nanobubbles look like stiff objects when investigated with ultrasonic shear waves. 

Figure 6.5 Shear modulus, Ga, of an epoxy adhesive, as determined by an ultrasonic Rayleigh wave technique, as a hmction of the thickness of the adhesive layer from the adhesive/aluminium alloy interface [20].

This study detects the defect of the void and the exfoliation in the solid phase diffusion bonding interface of ductile cast iron and stainless steel with a nickel insert metal using ultrasonic testing method, and examine the influence of mutual interference of the reflectional wave both the defect and the interface. 

Therefore, the establishment of the Non-Destructive Inspection technique to understand the presence of the defect on the bonding interface by the ultrasonic wave etc. accurately is demanded. And, the reliability of the product improves further by feeding back accurate ultrasonic wave information obtained here to the manufacturing process. 

Nondestructive Testing. Nondestmctive inspection of an explosion-welded composite is almost totally restricted to ultrasonic and visual inspection. Radiographic inspection is appHcable only to special types of composites consisting of two metals having a significant mismatch in density and a large wave pattern in the bond interface (see Nondestructive evaluation). 

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