25s
LITERATURE
half the pump pressure at a distance of about 35” nozzle diameters. In many cutting applications the first stage in the process would bc the impingement of a water jet on a surface at right angles. The initial cutting would depend upon the stress distribution within the target, which in turn would depend upon the pressure distribution produced by the water jet on the surface. A theory is given of the pressure ~listributic)Il on th\ target plate, which predicts that the pressure will fall to zero at about r-6 jet radii : this was found to bc in good agreement with experiments. I’rcliminary studies were made of the penetration of several types of rock by water jets of velocities up to about IO”” m/xc (pressures about 5000 atm). It was found that a I mm diameter jet drills a cylindrical hole about 5 mm in diameter. The pressure that the water jet produces at the bottom of such holes was measured and shown to fall off to about one-tenth of the nozzle pressure at a hole depth of about Z+cm. XXVII. IXscussion 3”9--31”.
of
paper
XSVI,
pp.
XXVlII. F. P. Bowden Conclusion. pp. 311-315, I table.
0. SURFACE ANALYSIS, TATlON AND TESTING
INSTRUMEN-
The Structure of Electrodeposited Copper Examined by X-ray Diffraction Techniques. E. Nf. Hofer and H. E. Hintermann, I. ~~ec~~oc~e~~.Sot., 112 (2) (rg65). X-ray diffraction line profiles of copper, electrodeposited from an acid plating bath in the presence of thiourca, have been analyzed by Fourier techniques. From the coefficients data on microstrains, crystallite size, twin-fault, and stacking-fault densities were obtained. The stored energy and the dislocation density have been derived from the value of the r.m.s. strains. The sums of the determination of the Fourier coefficients of tbe various diffraction peaks were calculated with a computer. The particle size as determined by the Fourier analysis varies between 135” and 180 a.The smallest particle size is obtained in a plating bath with a thiourea concentration of 20 mg/l. The deposits contain no stacking faults; the microtwin density is high. The microstrains are strong, indicating high values for the stored and the dislocation mO.25 Cdl/g, energy. density, -2 x 1011/cm?. A relationship was established between hardness and strain. Wear, 10 (1967) z.+5-z5g
APil)
CI‘XKENT
EVENTS
S-ray results wcrc compared with those ob tainctl from electron-microscopic~~l obscrvations on the same spccimcns. Defects in the Structure of EiecWodeposited Copper. Ii. >I. Hofer, I,. F. Chollet and H. I<. Hintermann, j. Electrochenz. Sm., 112 (1965) ,145, Three methods used to obtain characteristic ~~icrostructural quantities irl~portant for a better understanding of the mechanical properties and the behaviour of electrodeposited metals are described, compared and discussed. These techniques are electron microscopy, Fourier analysis of the X-ray diffraction line profiles, and small-angle, X-ray scattering applied on copper electrodeposits. In certain cases some of the structural parameters can be measured by two of these methods and the resu1t.s are compared.
Vacuum Envelopes for Ultra-high Vacuum Systems. J. T. Ozark, ~~~~~~uf~~~Et&g., 22 (IO) (1966) 398--407; 25 figs., 3 refs. Development of a Magnetic-tape Static Friction Testing Device. I’. T. Cole, U.S. Natl. Aeron. Space Ad&z. Tech. I%-&, NASA TN-D 3399, x966, 6 pp. Determination of the coefficient of friction of various materials used in magnetic tape formulation is discussed. Development of a Device for Ultrasonic Testing of Bearing Bushes. A. Matting and A. Heidemann, Material$hi~. , 8 (5) (1966) 175.-180; 7 figs., 3 tables, 5 refs. ITsability and life time of a slide bearing depend on the quality of the joint between lining metal and supporting shell. Therefore it is advisable to test the bearing bushes non-destructively before mounting. Theoretical considerations and practical preliminary tests show that ultrasonic testing (immersion technique) is a, suitable means for this purpose. The flaw detection sensibility is satisfying; joint defects as well as pores can be detected to a sufficient accuracy. 6.3. Testing Method of Selecting an Optimum Lubricant Testing System, I,. S. Akin, A.512 Trans., 9 (1966) z49--2s6. This paper presents a method of optimizing a system required for the experimental analysis of functional fluids used as lubricants. A system is chosen as a result of an analysis of the expected failure modes, the conditions under which the fluids must lubricate, the lubrication qualities of the fluids, as well as