Aluminum alloy

Pure aluminum is light and conducts heat well, but it is soft. Adding a little of other elements turns it into an alloy several times stronger that is almost as light. The alloy here belongs to the family most used for extrusions: aluminum with small amounts of magnesium and silicon.

It is made by melting aluminum in a furnace and stirring in measured amounts of magnesium and silicon, typically around half a percent to one percent each for extrusion grades. The melt is cleaned of gas and impurities and cast into long logs called billets. After the metal is shaped, a heat treatment called aging lets the magnesium and silicon gather into tiny particles of magnesium silicide spread through the metal. These block the metal's crystal layers from sliding, making it much stronger. Alloys meant for pouring into molds use far more silicon, often 7 percent or more, because it helps the melt flow into fine details.

In a TV it is extruded into the thin frame of the bezel and into the finned bars that become heat sinks. The same family, with grades such as 6061 and 6063, makes window frames, bicycle frames and laptop bodies.