Pyrex thermal expansion coefficient

Fig. 3.14. Relative linear thermal expansion coefficient of (1) Invar, (2) Pyrex, (3) W, (4) Ni, (5) Cuo.7Ni03, (6) stainless steel, (7) Cu, (8) brass, (9) Al, (10) Torlon, (11) soft solder, (12) Vespel SP-22, (13) Hg, (14) In, (15) Araldite, (16) Stycast 1266, (17) PMMA, (18) Nylon, (19) Teflon [60]. Some additional data are Ag between (8) and (9) Stycast 2850 GT slightly larger than (9). The integral contraction between 300 and 4K is 103AL/L = 11.5, 4.2, 6.3 and 5.7 for Stycast 1266, Stycast 2850 GT, Vespel SP-22 and solders...

Mercedes introduces the first supercharged automobile, the 6/25/40 hp Coming scientists invent Pyrex, a glass with a very low thermal expansion coefficient... 

Pyrex glass has been bonded to silicon using an anodic bonding technique. With it, the thermal expansion coefficients of the two materials are similar thus residual stress after bonding is minimized. Operationally, a mirror-polished, clean flat piece of glass is placed on top of a clean... 

A special type of glass named Pyrex 7740 is most commonly used in anodic bonding because of large sodium cation content and matched thermal expansion coefficient ( 32.5 X 10 cm/°C) with that of silicon. The approximate Composition of Pyrex 7740 is... 

Borosilicate glass contains about 80% silica, 13% boric oxide, 4% alkali, and 2% alumina. It is more heat-shock-resistant than most glasses due to its unusually small coefficient of thermal expansion (typically between 2 and 5 x 10 cm /°C for soda-lime glass it is 8 to 9 X 10 cm /°C). It is better known by such trade names as Kim ax and Pyrex. Bakeware and glass pipelines are often borosilicate glass. 

Pyrex glass contains about 80% of silicon dioxide, about 5% of alkalies, and has a low expansion coefficient. Ware made from it has a high thermal stability. The softening point of this glass is about 620 °C. 

Typical linear coefficients curves of aluminum, platinum, and Pyrex glass are shown in Figure 11.10. The loading on the probe is 5 g with various sizes of the samples indicated (18). Linear coefficients of thermal expansion for several metals and other substances, as determined by TDA, are given in Table 11.2 (19). Single crystals of the inorganic salts were used for all TDA measurements. 

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