Practice for Ultrasonic C-Scan Bond Evaluation of Sputtering Target-Backing Plate Assemblies

10.1520/f1512 ◽  
2020 ◽  
Author(s):  
Keyword(s):  
Backing Plate ◽  
Bond Evaluation

Hetero-Epitaxy of Group Va Metals on Sapphire

1972 ◽  
Vol 30 ◽  
pp. 492-493
Author(s):  
J. E. O'Neal ◽  
J. J. Bellina ◽  
B. B. Rath
Keyword(s):  
Thermal Contact ◽  
High Vacuum ◽  
Electron Beam Evaporation ◽  
Ultra High Vacuum ◽  
Backing Plate ◽  
Sapphire Substrates ◽  
Deposition Parameters ◽  
Polishing Damage ◽  
Reflection Electron Diffraction

Thin films of the bcc metals vanadium, niobium and tantalum were epitaxially grown on (0001) and sapphire substrates. Prior to deposition, the mechanical polishing damage on the substrates was removed by an in-situ etch. The metal films were deposited by electron-beam evaporation in ultra-high vacuum. The substrates were heated by thermal contact with an electron-bombarded backing plate. The deposition parameters are summarized in Table 1.The films were replicated and examined by electron microscopy and their crystallographic orientation and texture were determined by reflection electron diffraction. Verneuil-grown and Czochralskigrown sapphire substrates of both orientations were employed for each evaporation. The orientation of the metal deposit was not affected by either increasing the density of sub-grain boundaries by about a factor of ten or decreasing the deposition rate by a factor of two. The results on growth epitaxy are summarized in Tables 2 and 3.

Cased borehole acoustic-wave propagation with varying bonding conditions: Theoretical and experimental modeling

Geophysics ◽  
2019 ◽  
Vol 84 (4) ◽  
pp. D161-D169
Author(s):  
Can Jiang ◽  
Xue-Lian Chen ◽  
Yuan-Da Su ◽  
Xiao-Ming Tang
Keyword(s):  
Acoustic Wave ◽  
Wave Theory ◽  
Acoustic Measurements ◽  
Acoustic Wave Propagation ◽  
Velocity Change ◽  
Slip Boundary ◽  
Wave Measurements ◽  
Bonding Condition ◽  
Bond Evaluation ◽  
Cased Borehole

Acoustic measurements in cased boreholes are important for cement-bond evaluation behind the casing. In conjunction with a recently developed acoustic-wave theory using slip-boundary modeling, we carried out an experimental study for different cement-bond conditions. Four different cased-hole models were constructed, where the interface between the casing and the cement, and that between the cement and the formation, are decoupled or partially bonded to simulate the different cement bond conditions. An acoustic system is placed in the borehole to measure extensional casing waves along the borehole. By extracting the attenuation and velocity of casing waves from the experimental data, the bonding conditions were analyzed and compared with the theoretical modeling. The results indicate that, compared with the free-pipe situation, the casing waves are attenuated when there is some degree of bonding (good or poor) between the casing and the formation. However, when the poor bonding occurs at the cement-formation interface, the casing wave indicates significant velocity reduction and dispersion, the degree of the velocity change varying with the bonding condition. This wave phenomenon is predicted by the slip-boundary modeling. By adjusting the slip-boundary parameters in the modeling, the experimental results can be quantitatively modeled. These results are also confirmed by cased-hole acoustic logging data examples. The theoretical model can therefore be used to interpret cased-borehole acoustic-wave measurements.

Experimental Investigation of Single Point Incremental Forming of Aluminum Sheet in Groove Test

2017 ◽  
Vol 867 ◽  
pp. 177-183 ◽  
Author(s):  
Vikrant Sharma ◽  
Ashish Gohil ◽  
Bharat Modi
Keyword(s):  
Experimental Investigation ◽  
Incremental Forming ◽  
Single Point ◽  
Fractional Factorial ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Backing Plate ◽  
Groove Test ◽  
Factorial Design Of Experiments ◽  
Tool Diameter

Incremental sheet forming is one of the latest processes in sheet metal forming industry which has drawn attention of various researchers. It has shown improved formability compared to stamping process. Single Point Incremental Forming (SPIF) process requires only hemispherical tool and no die is required hence, it is a die-less forming process. In this paper experimental investigation on SPIF for Aluminium sheet has been presented. A groove test on Vertical Machining Centre has been performed. Factors (Step depth, Blank holder clamping area, Backing plate radius, Program strategy, Feed rate and Tool diameter) affecting the process are identified and experiments are carried out using fractional factorial design of experiments. Effect of the factors on fractured depth, forming time and surface finish have been analyzed using Minitab 17 software.

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