Standard mechanical test methods

What are the advantages of the small punch test over standard mechanical test methods described in Chapter 12 ... 

Along with the already discussed standard mechanical testing methods, there are highly precise techniques that are used specifically for the measurements of mechanical properties in colloidal... 

For the approval of a drug, it is necessary to know the results of elementary analysis, the structural formula, ultraviolet cind infrared absorption. X-ray diffraction and the other physicochemical properties of the substance. The test results on the forced decomposition, decomposition mechanism, etc., of bulk drugs are to be part of b-2 (Notification No. 43 of the PAB in 1992). The contents of the standards and test methods in the application form for new drugs should follow the guidelines on the standards and test methods for new drugs (Notification No. 586 of the PAB in 1994). 

Morphological characterization can be conducted by light and electron microscope techniques and by X-ray diffraction and thermal analysis, often used to determine crystallinity. Standard mechanical tests can be used to determine strength, extension to break in tension, and toughness. Normally, a selection of characterization methods is used with samples exposed for selected periods. When mechanical tests are used, the exposure period increment must be fairly short, in case a recovery phenomenon is present (see the section Engineering Properties—Consequences of Photodegradation ). Other tests related to appearance. 

While TMA is one of the older and simpler forms of thermal analysis, its importance is in no way diminished by its age. Advances in DSC technology and the appearance of dynamic mechanical analysis (DMA) as a common analytical tool have decreased the use of it for measuring glass transitions, but nothing else allows the measurement of CTE as readily as TMA. In addition, the ability to run standardized material test methods at elevated temperatures easily makes TMA a reasonable alternative to larger mechanical testers. As the electronic, biomedical, and aerospace industries continue to push the operating limits of polymers and their composites, this information will become even more important. During the last 5 years a major renewed interest in dilatometry and volumetric expansion has been seen. Other thermomechanical techniques will also likely be developed or modernized as new problems arise. 

This type of measurement is widely used in Europe [West German Industrial Standard (DIN) Test Methods for Gypsum Plaster (DIN 1168)] to determine the so-called water stucco factor, that is, the amount of stucco in grams that can be wetted by 100 mL water. The method consists of sprinkling stucco into the water at a specific rate without mechanical mixing. Therefore, it differs from other consistency measurements in that only spontaneous disintegration occurs. Pouring Consistency... 

The main forums for standardization in the UK were for many years either through BSI itself or via its role in support of ISO standards. For the materials testing and specification level, the work within ISO is undertaken in Technical Committee (TC) 61 (Plastics) mainly within Subcommittee SC13 (Composites and Reinforcement Fibers). In addition to this, many other subcommittees, such as SC2 for dealing with mechanical test methods, SC4 for fire tests, and SC12 for thermosets, develop relevant test methods covering both unreinforced and reinforced plastics. 

For practical reasons, mechanical testing methods are among those used most often to characterize aging. Suitable standard testing methods include ... 

The American Society of Mechanical Engineers (ASME) United Engineering Center 345 East 47th Street New York, NY 10017 The ASME Boiler and Pressure Vessel Code, under the cognisance of the ASME PoHcy Board, Codes, and Standards, considers the interdependence of design procedures, material selection, fabrication procedures, inspection, and test methods that affect the safety of boilers, pressure vessels, and nuclear-plant components, whose failures could endanger the operators or the pubHc (see Nuclearreactors). It does not cover other aspects of these topics that affect operation, maintenance, or nonha2ardous deterioration. 

In addition to chemical analysis a number of physical and mechanical properties are employed to determine cemented carbide quaUty. Standard test methods employed by the iadustry for abrasive wear resistance, apparent grain size, apparent porosity, coercive force, compressive strength, density, fracture toughness, hardness, linear thermal expansion, magnetic permeabiUty, microstmcture, Poisson s ratio, transverse mpture strength, and Young s modulus are set forth by ASTM/ANSI and the ISO. 

The American Society for Testing and Materials (ASTM) F4 Committee on Medical Materials and Devices has developed specifications for chemical composition, mechanical properties, and other factors. Standard test methods also are available from ASTM, 1916 Race Street, Philadelphia. The quaHty of castings is important for dental implants, and standards to define this would be useful. 

For physical, thermal, electrical, and mechanical properties, ASTM test methods are employed (28). Flammability ratings are often based on Underwriters Laboratories (UL) standards (29). UL flammabiUty ratings given ia this article are aot iateaded to reflect the hazards preseated by the resias uader use coaditioas. Typical properties are givea ia Table 3. More details and additional properties are given ia Refereaces 5 and 31—33. 

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