The Elements in Your Car
Have you ever wondered how many different metals it takes to make your car? Of course the older the car is, the more likely it is that these elements are fewer in number, but nevertheless diverse and highly complex as I hope to demonstrate. Iron of course is the main metal in all cars old or new except for specially made vehicles constructed principally for lightness when aluminium might be the predominant metal.
In all production cars iron will be there in the greatest weight.What is also true is that none of these metals are present in elemental purity (perhaps with the exception of copper and lead in certain cases); all are alloyed or compounded to one degree or another and this leads to even greater diversity. Thus iron is always found alloyed with carbon; in the case of cast iron as used for cylinder blocks and heads the level is about 2 to 4% with 1 to 3% silicon the latter two elements (carbon and silicon) being non-metallic.
High Strength, Low Alloy
When you reduce the level of carbon in the iron to .05 to .25% the metal becomes what we call steel and in HSLA (high strength, low alloy) steel used in modern cars many other metals are alloyed in small amounts including copper, nickel, niobium, vanadium, chromium, molybdenum, titanium calcium and zirconium. Even pre-war cars used vanadium sheet steels and typical steel for springs is iron with 0.8% carbon, 0.8% manganese and 0.03% phosphorus.
So you will see already that only touching on the main car constituent we have a wide range of metallic elements combined with non-metallic ones and this is only in the realm of the main structure. Iron will also be found where you have stainless steel which typically has from 10.5% to as much as 26% chromium in alloy to provide the resistance to corrosion that is decorative as well as desirable. Earlier we mentioned copper which as well as being found in small quantities in alloy with iron, also has an indispensible role in the electrics both in the wiring itself and the windings and commutators of dynamos and windings of solenoids and coils, and switch contacts.
Here it will be as pure as possible as impurities just impede electrical conductivity. Other metals like silver and gold are good conductors too but are not used for obvious reasons; however silver does find its way into the car as the reflective element on the headlamp reflectors at least on older cars, aluminising having succeeded it on more modern vehicles. Copper is also to be found in brass used in electrical fittings and other car parts such as radiator shells, headlamp shells and even hubcaps in old cars - usually an alloy of about 65% copper and 35% zinc. Bronze bushes also contain copper (around 80%) with tin (about 15%) and perhaps also lead or zinc, and tin also appears as solder in alloy with lead and sometimes also antimony which is a metalloid like silicon. Antimony sometimes also turns up alloyed with lead in lead–acid batteries where the maker has decided on an alloy rather than pure lead.
Aluminium
Aluminium is usually the second most abundant metal in cars and can be found in engine block and head castings, pistons and con-rods, bell housings and gearbox cases as well as being used in panels for more expensive cars. The aluminium is usually some form of alloy with 95% or more of aluminium and other metals such as copper, magnesium, manganese, silicon or zinc. Zinc is also the element used to protect steel parts with a coating either electrically applied or ‘hot-dipped’ at about 460 centigrade. This is commonly known as galvanizing and derives from the name of Luigi Galvani (1737-98) who was an early experimenter with electricity.
As we have seen, zinc is often found in cars alloyed with other metals and it is one of the principal metals in the ubiquitous casting alloy Mazak (known in America as Zamak – its name derives from the German names for its constituents; Zink, Aluminium, Magnesium, Kupfer [copper]). The English name has the complication of incorporating the initials MA for Morris Ashby who produced the alloy under license in England in the 1930’s. In this alloy zinc is about 95% with 4% aluminium, 1% copper and a trace of magnesium. It is the usual metal of door handles, often carburettors, and other small castings. For external use it is invariably chromium plated.
Chromium
This takes us to chromium which has already been mentioned as alloyed with iron in stainless steel, it is of course most recognised as an embellisher and protector of base metals such as brass and steel. In fact it does not really protect steel bumpers or brass radiator shells very much as the final chrome finish is measured in microns and the underlying coats of electrolytically applied copper and then nickel are the real protectors – chrome provides that bluish-silver sparkle we all love. In England cars have been ‘chrome plated’ since about 1928; prior to that nickel was used. And there you have copper and nickel popping up again! Lead often turns up in alloys of all sorts and is found as almost pure lead in some lead-acid batteries which still dominate in the car industry, after a hundred years or so, with lithium-ion batteries being those used for propelling electric cars, but unless you have such a car, you won’t find much lithium in your vehicle.
But you will find other perhaps unexpected metals such as sodium, potassium and calcium somewhere other than in alloys. These three elements exist with many others in the windows! Glass like many alloys has various forms but a general formula would be 70% quartz sand (silica or silicon dioxide), 13% soda (sodium carbonate), 10% lime (calcium carbonate) with the balance made up with dolomite (calcium-magnesium carbonate), feldspar (which is a mixture of potassium-aluminium silicate, sodium-aluminium silicate and calcium-aluminium silicate), and finally potash (potassium carbonate). So you will see from all this that your car is perhaps a rather more complicated machine than you may have once thought.
