Fabrication metal forming techniques

Addnl Refs on Explosive Fabrication of Metals, A) 1.1. Islamoff, Metal-Forming Techniques , NASA, SP-5017(May 1965)... 

Some ductile plastics, such as PC and ABS, can be fabricated like metals with punching and cold-forming techniques. These processing techniques are analogous to the hardness tests in that a rigid indentor is pressed into a sheet of a less-rigid plastic. 

Ultrasonic machining, also known as ultrasonic impact grinding, uses ultra-sonically induced vibration delivered to a tool to create accurate cavities and channels of many shapes [146]. It can be used to form deep cavities as small as 250 pm in diameter (with an accuracy of 50 pm) in both hard and brittle materials such as glass, quartz, polymers, ceramics and metals. This technique may be useful for fabrication of large masters. 

A lot of research has also been devoted to the infiltration of macroporous templates by reactive components. Porous polymeric material was synthesized by either infiltration of a monomer-initiator mixture with subsequent polymerization [29], or by infiltration of a prepolymer solution, which can be UV-cured afterwards [27]. A quite common route to fabricate metal oxide networks is to infiltrate the precursor structure with its corresponding sol-gel solution, which eventually hydrolyzes and solidifies in the desired porous shape. This technique has been shown for a great variety of materials (compare Table 2 in [10], Table 1 in [37], and Table 1 in [38]), such as silica [52], titania [30,50], zirconia [30] or aliunina [30], just to mention a few. Another pathway to metal oxide structures was introduced by Park et al., who precipitated acetate salt solutions of the desired material in the free voids. After addition of oxalic acid the porous metal oxide was formed during the combustion of the latex template [73]. 

Manufacture of nanostructured or nanograined metals and alloys mainly relies on two categories of approaches, one for producing fine powders (i.e particulates) and the other for bulk materials. To date, numerous fabrication and synthesis methods of nanostructured metals in both particulate and bulk forms have been developed, but many of them are still distant from industrial-scale production. This section focuses on the fabrication and processing techniques that have high potential for industrial manufacture. 

Quite a variety of different techniques are employed in the forming of polymeric materials. The method used for a specific polymer depends on several factors (1) whether the material is thermoplastic or thermosetting (2) if thermoplastic, the temperature at which it softens (3) the atmospheric stability of the material being formed and (4) the geometry and size of the finished product. There are numerous similarities between some of these techniques and those used for fabricating metals and ceramics. 

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