Thermal conductivity table

In appUcations in which electrical conductivity is required, metals, copper, tungsten, molybdenum, and Kovar [12606-16-5] are the preferred chip-carrier materials. Metals have exceUent thermal conductivities. Tables 2 and 3 Ust the various materials used for substrates, along with their mechanical, electrical, and thermal properties. 

The transmission of heat is favored by the presence of ordered crystalline lattices and covalently bonded atoms. Thus graphite, quartz, and diamond are good thermal conductors, while less-ordered forms of quartz such as glass have lower thermal conductivities. Table 7.3 contains a brief listing of thermal conductivities for a number of materials. Most polymeric materials have X values between 10 and 10° W m- K"1. 

Lithium and its compounds may be used in fusion reactors in either liquid or solid form. Liquid Li is an excellent coolant with low density and viscosity, and with high heat capacity and thermal conductivity (Table 1). Consequently, it is used in many designs as a combined breeding material and coolant. However, hot molten Li can react violently with water or air under certain conditions. Hence, either strict engineering design must preclude large scale Li - air or water reactions, or another form of Li must be used. Both approaches have been studied. 

Insulation suited to cryogenic equipment are characterized by multiple small spaces or pores that occlude more or less stagnant air of comparatively low thermal conductivity. Table 8.19 lists the most common of these materials. In application, vapor barriers are provided in the insulating structure to prevent inward diffusion of atmospheric moisture and freezing on the cold surface with resulting increase in thermal conductivity and deterioration of the... 

Samples measuring 50 x 6 x 3 mm were thermally shocked by quenching from 1000 or 1200°C into room temperature water. Flexural strengths measured before and after thermal shock are shown in Table III. The relatively low composite thermal conductivity (Table I) does not adversely affect thermal shock behavior. Repeated thermal shocks from 1000°C to room temperature water for five cycles results in only a modest decrease (15%) in room temperature strength. 

FRP composites, as a combination of fibers and polymer matrix, show also lightweight and high strength. In addition, because of the polymer matrix, they present high corrosion resistance and low thermal conductivity. Table 1.2 shows a comparison of basic material physical properties of FRP composites and other common constructive materials [11]. 

Materials having the highest thermal conductivities are the metals, metal alloys, and some ceramics while plastics, polymeric materials, and glasses have the lowest thermal conductivities (Tables 2.5,2.6, and 2.7). 

Two-electron covalent bonds are formed between the metal (Me) and silicon atoms in monosilicides. The overall electron-valence nature of these bonds determines the uniformity of the crystal structure of silieides. The high value of their lattice thermal conductivity (Table 2) is an indirect confirmation that stable covalent bonds are present in monosllicide crystals. The uniformity of the structures amounts not only... 

A high modulus fiber will reduce the coefficient of thermal expansion and increase the thermal conductivity (Table 16.1). 

Functional Fillers. A variety of fillers can be used to add specific properties. Metals, and beryllium and aluminum oxides, can be added to increase thermal conductivity (Table 3.33). Metals can be added to increase electrical conductivity (Table 3.34). Graphite increases lubricity and electrical conductivity. Mica increases elec-... 

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