hen thinking about metals and which is the strongest, it’s often assumed that there’s an easy answer, but how do you determine what makes a metal the ‘strongest’?
Strength can be measured in a strength to weight ratio, as a metal that is light-weight but extremely strong. A metal that doesn’t deteriorate in high temperatures could also be considered strong. If you don’t take weight into account, or temperature limits, then the answer to the question ‘What’s the strongest metal?’ changes. You also have yield strength to consider; the degree to which a material can be put under stress until its elasticity fails completely and it’s left deformed permanently. Tensile strength is more commonly used, it’s the amount of pulling force that can be applied before it weakens and breaks apart. With all this taken in to account, the question has multiple answers depending on the uses of the metal.
Titanium is often thought as the strongest metal but it’s only the strongest metal in regards to strength to weight; arguably this makes titanium the most useful metal. Its ideal applications are in aerospace, aircraft and engine components, due to it being highly resistant to heat. Another unique property of titanium is that it’s highly resistant to corrosion in sea water and chlorine. In its unalloyed condition, titanium is as strong as some steels but around half the weight.
There are multiple metals stronger than titanium, certain stainless steels, as well as tungsten. Tungsten is the strongest metal in natural form; found in its pure form with a tensile strength of 1510 mega-pascals. It has the unique property of having the highest melting point of any pure metal, only surpassed by carbon on the entire periodic table. It’s not a widely used metal due to being very dense and brittle. It’s most common use is in military projectiles or inside light bulbs as tungsten filaments.
The strongest alloy metal without accounting strength to weight (titanium) is steel. Steel alloys are continuously changing to get different variations and properties. Vanadium steel alloys can have up to 5205 tensile strengths. Steel itself is an alloy of carbon and iron, though other elements added to this can give it different strengths and weaknesses.
If strength is determined by the surface hardness of a metal then the answer would be Chromium. The surface hardness of a mineral is resolved by the Mohs Scale, used to define the scratch resistance of a mineral. Diamonds take the crown as the hardest material known to man, but chromium wins when it’s limited just to metals. Chromium can be combined and used as an ingredient to form stainless steel, protecting against corrosion and physical damage. Alloys of iron, nickel and chromium are highly resistant to heat; they’re used in similar ways to titanium – in aircraft or jet engines.
About the author:
Simon Moore is the MD of Midbrook Steel Buildings based in Derbyshire of the UK.
Midbrook specialize in Steel Framed Buildings for the commercial building industry.