Single phase plastics examples

Some examples of the grain-size effect in ceramics are illustrated below Ti3SiC2 was chosen as one exemplar, since this ternary compound exhibits a unique combination of properties. It is a layered material that is as machinable as graphite. At the same time, CG (100-300 pm) samples of Ti3SiC2 have been observed to be damage-tolerant, not susceptible to thermal shock and oxidation resistant. The specimens are fully dense, bulk, single-phase polycrystalline samples of Ti3SiC2. This material exhibits brittle failure characteristics at RT, but is plastic at 1,300 °C with yield points of 300 and 100 MPa under compression and flexure, respectively. 

Contrary to metals, ceramics do not yield plastically when loaded. Therefore, cracks cannot grow under cyclic loading by localised plastic deformation at the crack tip. Furthermore, no intrusions and extrusions can form on the surface of an initially smooth specimen by dislocation movement. Because of this, many ceramics do not exhibit any cyclic effects i. e., there is no difference between their behaviour under static and cyclic loads. All loads that they can bear once, they can bear infinitely many times. For example, this is the case in fine-grained ceramics with a single phase i.e., many technical ceramics. 

Alloy a- 16i also 9- Il6i n [F aloiy fr. OF alei, fr. aleir to combine, fr. L alligare to bind] (1604) A blend of a polymer or copolymer with other polymers or elastomers. An important example is a blend of styrene-acrylonitrile copolymer with butadiene-acrylonitrile rubber. The term polyblend is sometimes used for such mixtures. Some writers restrict the term allow to mixtures of polymers that form a single phase, reserving the term blend for nonhomogeneous mixture. The sale of plastics blends and alloys worldwide was 1.3 billion pounds (0.95 Tg) in 1987 and was predicted to have increased by more than 50% by 1992. 

Chemistry is everywhere, even in industries that do not seem chemical. Making a single electronic microcircuit, for example, involves nearly one hundred different chemical processes. The air we breathe, the water we drink, the food we eat, and even the sunlight that we used to bask in, all are affected by chemical processes that we understand better thanks to new research. We depend on synthetic materials in our homes and workplaces, and even in our clothing. Our society is built in large part on plastics and semiconductors. Many of the problems that we confront have causes that chemistry can elucidate. Many of the remedies that we apply to these problems are chemical remedies, which often, as in the agreement to phase out CFCs, involve political solutions too. Whether we like it or not, the present scale of food production around the globe would be impossible without extensive use of chemical aids, in the form of pesticides and fertilizers. 

Figure 8 shows the volume as a function of time for four overdriven single shock wave simulations in the [110] direction of a 25688 atom perfect Lennard-Jones face centered cubic crystal. Elastic compression is characterized by VjV 0.9 and plastic compression occurs for smaller volumes. As the shock speed decreases, the amount of time the molecular dynamics system spends in the elastically compressed state increases. This plot illustrates how the final thermodynamic state in the shock is a function of the simulation duration when slow chemical reactions or phase transitions occur. For example, on the 10-20 ps timescale, the 2.8 km/sec shock has an elastically compressed final state on the 100 ps timescale, this simulation has a plastically compressed final state. 

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