title: Ultrasonic couplants for acoustic microscopy of low speed materials.
abstract: A method is presented for estimating the compression wave velocities of organic fluids, based only on their density and molecular properties. The method is applied to a search for very low-speed ultrasonic couplants, suitable for 250 MHz acoustic microscopy studies of epoxy materials. Experimental measurements confirmed that acoustic velocity could be predicted within 3% for simple fluorine-containing organic compounds, and within 10% for those with a more complex molecular structure. The compound 2-dichloropentafluoropropane (C(3 )HCl(2)F(5)), with a compression wave velocity of C(L)=638 m/s and acceptably low attenuation coefficient, was identified as a good coupling agent for acoustic microscopy studies of low speed materials.
authors.affiliation: Dept. of Mech. Eng., Toronto Univ., Ont.
authors.forename: V S
authors.initials: VS
authors.lastname: Ardebili
authors.forename: A N
authors.initials: AN
authors.lastname: Sinclair
authors.forename: J K
authors.initials: JK
authors.lastname: Spelt