A new production technique: ion milling

1981 ◽  
Vol 21 (2) ◽  
pp. 289
Author(s):  
L. D. Schwartz ◽  
C. M. Lukaniuk ◽  
T. H. Estell

Author(s):  
Arno Pronk ◽  
Qingpeng Li ◽  
Elke Mergny

In the past, record breaking large shell structures with ice composites were successfully realized by spraying cellulose-water mixture on an inflatable mould. This paper presents the application of a new, production technique for ice composites by extrusion instead of spraying. With this additive manufacturing technique, the world's first gridshell in fibre-reinforced ice was designed, constructed, and tested. To increase the stiffness of the gridshell the floorplan of the inflatable mould was designed with an anti-clastic curvature at the supports of the structure. Concerning the pattern of the grid different options were developed and compared and verified in ABAQUS®. The size of the struts were determined by an iterative process. The gridshell was realized in a cold environment by printing multiple layers of cellulose-water mixture on the inflatable mould using piping bags. After the substance has been extruded, the mixture froze at temperatures of minus eight degrees Celsius or lower. The realized structure was tested on-site with a dead load to prove its strength.


1995 ◽  
Vol 49 (3) ◽  
pp. 532-536
Author(s):  
E. Savola

Measurement ◽  
2006 ◽  
Vol 39 (7) ◽  
pp. 674-679 ◽  
Author(s):  
Vedat Tanyıldızı ◽  
Haydar Eren

Author(s):  
L. D. Ackerman ◽  
S. H. Y. Wei

Mature human dental enamel has presented investigators with several difficulties in ultramicrotomy of specimens for electron microscopy due to its high degree of mineralization. This study explores the possibility of combining ion-milling and high voltage electron microscopy as a means of circumventing the problems of ultramicrotomy.A longitudinal section of an extracted human third molar was ground to a thickness of about 30 um and polarized light micrographs were taken. The specimen was attached to a single hole grid and thinned by argon-ion bombardment at 15° incidence while rotating at 15 rpm. The beam current in each of two guns was 50 μA with an accelerating voltage of 4 kV. A 20 nm carbon coating was evaporated onto the specimen to prevent an electron charge from building up during electron microscopy.


Author(s):  
G. G. Shaw

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.


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