Tool shape

Tools shape how we think when the only tool you have is an axe, everything resembles a tree or a log. The rapid advances in instrumentation in the last decade, which allow us to measure and manipulate individual molecules and structures on the nanoscale, have caused a paradigm shift in the way we view molecular behavior and surfaces. The microscopic details underlying interfacial phenomena have customarily been inferred from in situ measurements of macroscopic quantities. Now we can see and fmgeT physical and chemical processes at interfaces. 

Another important parameter is the electrode polarity. Using an anode compared with a cathode results in very different microhole shapes, as discussed in Section 5.4. The microhole profile is also a function of the tool shape. For cylindrical tools (cathodes), the typical profile is conical but the hole bottom presents in general two bumps. These bumps, due to localisation of the discharges at the tool edges, are more pronounced for ceramic and composite materials than for glass [19]. 

Tool Shape Flat Sidewall and Flat Fronts -... 

The combination of tool-electrode rotation, tool shape, and optimal pulse duty ratio results in this excellent result. 

Tool-electrodes can be fabricated in several ways. An excellent and flexible solution is wire electrical discharge grinding (WEDG), which is well suited for microfabrications [85]. An alternative way is to use anodic etching of tungsten. As shown by Lim et al. [82] very thin cylindrical electrodes (down to 50 pm) with controlled diameters can be fabricated. The important point is to use a high concentration of the electrolyte (typically 5 M KOH) and relatively high current densities around 10 mA/mm2. Thus, the diffusion layer around the electrode can be controlled in order to achieve various tool shapes by anodic... 

There is an almost infinite variety of possible tool shapes, and fabricating tool steel profiles and conducting experimental trials is expensive. Hence, the potential of modeling is particularly great in the area of tool design. Colegrove and Shercliff (Ref 45 7, 50) used the 2-D CED methods discussed in section 10.3.5, Tool Material Interface Conditions, to study a series of profiles, as illustrated in Fig. 10.9. The sensitivity of the flow pattern, torque, and traverse force to tool shape was compared for 2024, 7075, and 7449 aluminum alloys. Experimental... 

Tool Shape and Trajectory Definition In order to curb a great variety of all possible tool shapes and sizes, the industry focuses on the standardized geometric definition of a generalized cutting tool that is based on the APT definition. The most comprehensive shape of an APT cutter may consist of the bottom and side lines and fillets connecting the lines, as shown in Fig. 5. However, in practical applications, the range of used tool shapes is narrower. The most used tool shapes, also in five-axis machining, are shown in Fig. 6. 

In a second method, five-axis tool path generation algorithms usually do not use (i, j, k) notation for tool orientation. It is replaced by a notation that includes two angles which can define tool orientation within the LCS. These angles are easier to use to align tool shape to the local surface properties. There are two ways to define these angles ... 

Ion Beam Machining, Fig. 3 Micro cutting tool shaped by focused ion beam direct writing (Zhang et al. 2009)... 

Zhang SJ, Fang FZ, Xu ZW, Hu XT (2009) Controlled morphology of micro tools shaped using focused ion beam milling technique. J Vac Sci Technol B 27(3) 1304-1309... 

Tool shapes can be complex. For example, O Bradaigh etal. (1991) formed fiat, eight-ply, quasi-isotropic sheets into a rectangular cargo trailer bed with cylindrical wheel wells. The diaphragm can be any material that supports the laminate and that deforms to the component shape under the applied pressure. Composite aircraft structures, which are expensive by any process, are formed between superplastic aluminium diaphragms (Raman and Barnes, 2010). The procedure fabricates three parts the composite laminate... 

Schematic of the tool removal process (a) prior to tool removal, part and tool in equilibrium, part conformed to tool shape (b) tooling removed, residual tool/part interface forces remain (c) add negative of interface loads to obtain stress free interface (d) predicted part shape after tool removal. 

The cathode is a tool shaped to conform to the desired cut in the workpiece. The tool is usually made from copper, steel, or alloy and insulated on the sides to give directed current lines. The tool is moved during electrolysis to maintain a constant small gap (about 0.25 mm) between the electrodes to reduce the voltage required. 

The type of machining determines the tool shapes. Circumferential grinding wheels are customary for circular grinding, but likewise for spherical surfaces. Cup wheels are used for the working of flat and spherical surfaces, core drills for through-holes or for the production of rods, as well as various types of special shaped tools. 

A fast metrology is needed to control the lapping process and continuously to obtain the exact topography of the optical surface. With that information the tool shape can be adapted to the next figuring step, as can the function of the tool wear rate. Lapping and testing become an iterative process. 

High degree of shape complexity possible, limited only by ability to produce tool shape. 

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