The extra-sponge sponge titanium and sponge titanium product sieve prepared by magnesium reduction method (these sieves are coarse titanium powder) are directly ground and pulverized by an ordinary ball mill to obtain the equi-exterior titanium powder. This is the simplest direct crushing method. However, this method must be effective against external titanium particles that are brittle, and is not effective for titanium sponge with good toughness, and the efficiency is low.
Obtain coarse titanium powder with high impurity oxygen and iron content.
Another method is to cool the metal titanium, such as sponge titanium, titanium ingots, and residual titanium chips, to -129 ° C in an inert liquid (such as liquid nitrogen) after surface purification and drying, and use its low temperature brittleness in the grinder Grinded in the middle, and finally through the magnetic separation, screening and other processes to obtain powder titanium. The titanium powder produced by this method is easily polluted by air and crushing equipment during the grinding process, so the purity of the product is not high, especially the content of oxygen and iron is high. If the titanium metal chips are cooled to -130 ° C and grinded in a vortex grinder, the quality of the titanium powder can be improved.
Using the vortex grinder is much more efficient than the ball mill. On the one hand, the low-temperature sponge titanium is brittle, on the other hand, the vortex grinder can also crush the metal with good toughness and high efficiency. But only suitable for grinding with coarse titanium powder and small pieces of titanium scrap, it can get finer titanium powder.
Mechanical alloying (MA). The mechanical grinding technology has further developed, and the most advanced process to date is the use of agitated ball mills or other high-energy ball mills. This kind of ball mill can be applied with energy and stirred by the rotor to force the materials added to the mill and the grinding balls to rotate rapidly and strongly with each other while grinding, while gradually mixing and alloying the materials. As a result, it developed into a new process, which is mechanical alloying.
Mechanical alloying is a process that uses a high-energy ball mill to vigorously grind to produce titanium-based alloy powder. It is loaded with effect-based compounds or mixed powder and grinding media (usually quenched steel balls) into the ball mill, filled with argon protection (usually also need to add a small amount of process control agent to prevent cold welding during grinding), start grinding. At this time, the powder particles undergo continuous welding-fracture-welding process, which is continuously ground and mixed gradually, and alloyed powder with very fine particle size can be produced.
The biggest advantage of this process is that the materials to be ground can be matched in any proportion, either single alloy materials or various mixture materials. Another advantage is that the particle size of the powder obtained is particularly fine. Therefore, fine materials can be produced by this process. Many scholars are using it to develop titanium-based composite materials, including the development of nano-structured intermetallic compounds and composite materials, such as Ti-6A1-4V / SiC, titanium aluminum compounds / titanium silicon compounds; also include the development of amorphous, microcrystalline, quasi-crystalline Crystal and nano powder.
Performance Of Titanium Powder Produced By Direct Crushing Method
