TITANIUM 6AL4V BALL or, 6AL4V-ELI, and CP-1 ( Commercially Pure ) are very human body or bio compatible. Basically what this means is that the human body does not reject these materials. This metal is widely used in the medical industry. Because of this bio-compatibility, it is used in many medical implants.
At the peak of body jewelry sales, we were investigated by the government to find out what we were doing with all of the Titanium. We had become the tenth largest consumer of this metal in the country. The body jewelry industry has calmed down from this peak, but Titanium balls are still a common material for body jewelry.
In the realm of electro chemistry Titanium metal is again very unusual. Titanium will anodize, vivid dichroic colors that extend from a dull gray to blue, then a vivid purple and ultimately a brilliant gold. Using anodes and thieves’ vivid landscape like patterns can be crated.
Titanium is an interesting metal. With very few exceptions the crystalline structure of all metals is in the form of a cube, but Titanium has a very usual Hexagonal Close Pack structure. One of the effects of this unusual structure is that Titanium can be electro mechanically processed to yield a satin finished ball with almost perfect sphericity and size that has exceptional optical properties. Although the surfaces of the satin finished Titanium ball will reflect a fair amount of visible light (about 17%) there is absolutely no spectral reflectivity. The surface is not shiny or glossy. There are no hot spots of high intensity light. This unusual property makes satin finished Titanium balls perfect archival targets for calibrating optical measuring equipment of all kinds. These same properties allow the production of nearly perfect flat test artifacts without any spackle.
Titanium is one of the most totally non magnetic of metals. We were called on to produce a considerable number of rather large diameter Titanium balls with of close dimensional tolerances and exceptional surface quality. These were used in a satellite to study gravity waves. The main reason for choosing this metal was its magnetic transparency.
The strength to weight ratio for Titanium is very high. It weighs only 60% of steel. This means it is 40% lighter than steel.
Titanium is a very strong metal. The hardness measurement is 36 HRC, and the tensile strength yield is 128,000 PSI.
Solid pieces of Titanium metal are no more flammable than Aluminum, but fine Titanium chips are very flammable. The fire hazards of machining Titanium must be guarded against. Titanium is very incendiary. I worked in a machine shop that was fly cutting some Titanium castings on a brand new vertical milling machine, the operator allowed a pile of fine chip to accumulate on the knee, behind the table. The fly-cutter threw a spark into this pile of chips, and a white hot fire resulted. When the fire burned out, that brand new milling machine was a twisted pile of scrap iron.
When we are done expounding on the wonderful merits of Titanium, it is a very expensive metal, (in 2008 we were paying over $60.00 per pound for 4.25 inch diameter raw material).
Titanium is a very difficult material to work with. It can not be cold headed (cold formed). Cold heading is usually the first step in the manufacturing of precision balls. See our paper on “How Balls are Made.” In order to form Titanium, it must be raised to a temperature of 800°F.