Friends who are familiar with titanium metal know that there are many sayings about titanium. For example, what is the difference between titanium steel, pure titanium, and titanium alloy that we are familiar with? Let's briefly explain today.
The name -titanium steel is not a standard academic name, but a commercial name. Because 316L stainless steel has better corrosion resistance and acid and alkali resistance than ordinary stainless steel, the standard grade is 022Cr17Ni12Mo2, which mainly contains Cr, Ni, and Mo, and the number indicates the approximate percentage.
It can be seen that titanium steel does not contain titanium, and its main component is still iron. This commercial name is to distinguish it from other stainless steels when used as jewelry, and to obtain higher value. In fact, the cost and sweat resistance of 316L stainless steel are indeed better than those of common stainless steel.
There are generally two types of titanium that can be called titanium, one is pure titanium, and the other is titanium alloy.
The highest titanium content is freshly made sponge titanium, which is made from titanium tetrachloride reduced by magnesium. It looks like this:
is loose and porous, its strength is very low, and it cannot be used directly as titanium material. It is the most upstream material of titanium material. After smelting, forging and rolling, it is processed into various shapes of plates, wires, tubes, etc.
The titanium content of sponge titanium is close to 100%. But titanium is too active, and it can easily react with oxygen, nitrogen, hydrogen, etc. in the air when exposed to air, so it is almost impossible to achieve 100% purity.
Generally speaking, those with a titanium content of more than 95% become industrial pure titanium. Pure titanium is divided into GR1-GR4 according to the difference of titanium content and impurity content. We usually have GR1 and GR2. Impurities are mainly oxygen, nitrogen, hydrogen, carbon, iron and so on. The higher the titanium content, the softer it is. We say the lower the strength, but the better its toughness.
So when we make titanium belt buckles and titanium jewelry, we will use GR1 material where the force is not strong, while shafts and small screws will use GR2 material.
When we make pure titanium cups, we cannot use GR2. The higher the purity, the better, especially the hydrogen content must be low, otherwise it will be easy to crack due to insufficient toughness, or there will be more obvious stretch lines. Or pitting, the scrap rate will be quite high.
Titanium alloy, as the name suggests, is an alloy formed by titanium and other metals and non-metals. These metals and non-metals such as aluminum, molybdenum, vanadium, chromium, iron, zirconium, tin, oxygen, carbon, etc. Titanium alloys are divided into TA, TB, and TC series according to the different metallographic structure. Do not delve into it here.
Take the most commonly used GR4 titanium alloy as an example. Its titanium content is 90%, aluminum 6%, and vanadium 4%, so it is also called titanium 6 aluminum 4 vanadium. TC4 titanium alloy is the earliest developed and most widely used titanium alloy in the world. It is also the earliest titanium alloy used in medical treatment. Its output accounts for more than the total output of various titanium alloy products in the world. It is even more important in the aerospace industry. More than 80%. It has high corrosion resistance, higher strength than pure titanium, good toughness, relatively easy processing and welding, so the overall performance is very good, and like pure titanium, it will not cause allergies.
Is pure titanium better or titanium alloy?
This is inconclusive. Different materials are suitable for different products. Generally speaking, excluding factors such as shape, the material cost of titanium alloy is higher than that of pure titanium. Of course, the titanium alloy here needs a regular grade, which is based on titanium and other metals and non-metals are added, instead of adding a little titanium to other metals, and if it contains a little titanium, it will pretend to be a titanium alloy.
