As we all know, or at least we all know that at some point we have been in contact with this metal, zinc is grayish white or bluish white. It has a metallic luster, can take on a high gloss, and quickly tarnishes with ordinary air.
When zinc is crushed, its microstructure becomes homogeneous and its hardness increases. Annealing restores the crystal structure. Molten metal “cries” weaker than tin.
Zinc is brittle at normal temperatures, but becomes malleable and ductile between 100 °C and 150 °C. Metal is hot rolled on a large scale, but still malleable enough after heating to be able to re-roll or stretch it of wire. Above 205 °C, zinc is again brittle enough to be pulverized in a mortar.
Zinc has a clearly plastic behavior between 200 °C and 400 °C, and hot metal can be structed through an opening.
The density of zinc distilled at 20-24 °C is 6.9225 g / ml, increases to 7.12722 g / ml after compression by 10,000 atmospheres, but varies with the history of the metal and generally decreases with “work ”
Schiff found that the density of granulated zinc at 12 °C varies between 6,966 to 6,975 g / ml, and recorded the determinations by other observers to vary between 6,861 to 7.1908 g / ml. According to Kalischer, a coiled zinc specimen of density 7.1812 has a density of 7.1841 when crystallizing between 130-300 °C.
The density of zinc decreases when melting according to the following expression: D = 6.59 – 0.00097 (T-419), for any temperature T. The slight contraction during solidification adapts the metal to the castings.
The vapor density of zinc corresponds to a monatomic molecule. When zinc dissolves into mercury, it depresses the vapor pressure as if its molecule were monatomic.
Zinc melts at 419.4 °C. The latent heat of fusion of zinc is approximately 1,730 Cal.
Berthelot found that 920 °C is the boiling point of zinc. Previous researchers had found higher temperatures. It has recently been assigned 918 °C as the boiling point.
In a vacuum, zinc slowly volatilizes at 184 °C and boils at 550 °C. According to Heycock and Lamplough, the boiling point is altered by 0.133 °C per mm. difference from normal pressure.
Thermal conductivity decreases with temperature to its melting point. Subsequently there is a sharp decline followed by another gradual increase. According to Lees, the thermal conductivity of redistilled and pure molten zinc ranges from 0.20 to -170 °C to 0.268 to 18 °C. According to Jager and Diesselhorst, it is 0.265 to 18 °C for pure molten zinc and 0.262 to 100 °C.
The linear expansion coefficient is 10.06 × 10-6 between -183 °C and 12.6 °C, and 17.11 × 10-6 between 19.3 °C and 100.2 °C.
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