Tungsten alloy is a two-phase alloy with high density (> 16.5g/cm3), which is also known as high density tungsten alloy.At present, high density tungsten alloys are not only widely used in aviation, aerospace, weapons and other military fields, but also more and more in civil industry.The preparation process of high density tungsten alloy is as follows:

   1、The first is the composition design. In high density tungsten alloys, tungsten content is generally 85-98 wt%.In addition to W, Ni and Fe (Cu) are the most abundant elements in high density tungsten alloys.In the preparation of high density tungsten alloys, elements such as Mo, Ta, Re and La are added.

   2、The second one is powder making. The alloy with excellent mechanical properties can be prepared by using powder with high purity, small particle size and good uniformity. In the field of powder making, nano-powder is a research hotspot. There are two main types:

   1) spray drying method, spray drying method is the first choice to prepare a certain component of the original salt solution, salt solution including tungstate and metal chloride, etc. Because of the rapid evaporation of solvents and the rapid deposition of solutes in small droplets, powder crystals with uniform chemical composition can be obtained.

   2) Mechanical alloying method, mechanical alloying method is to select a certain proportion of tungsten alloy initial powder and metal ball into the ball mill, powder under the unequal speed of the metal ball, through cold welding and deformation for many times, eventually get the composite powder with finer structure and more uniform composition.

  3、The third is forming. The traditional forming process of tungsten alloy is die forming. The new replacement process is powder extrusion forming and powder injection molding.Because these two methods mix tungsten alloy powder with forming agent and inject it into the forming machine by extrusion, they have remarkable advantages in the preparation of parts with complex shapes. Besides, powder extrusion and powder injection moulding technology have wide applicability due to the addition of forming agent.

  4、The fourth one is sintering. Because the solid phase sintering method requires high size of the original alloy powder, the liquid phase sintering method takes a long time to sinter, and is prone to collapse and deformation.Based on the advantages and disadvantages of both, a two-step sintering process of solid phase sintering and liquid phase sintering was proposed. Because the deformation of the two-step sintering is small, the structure of the tungsten alloy obtained is more uniform and the material properties will be greatly improved, so the two-step sintering is widely used. In addition, the newly developed microwave sintering and spark plasma sintering technologies are also being popularized and used in recent years.

  5、The fifth item is the use of tungsten alloy. 1) Sports products series: professional tungsten alloy darts benchmark, tungsten alloy fishing drop series: bullet type, water drop type, circular tube type, semi-water drop type, cylindrical hole type. Tungsten bead and tungsten ball series: 1.5mm-10 mm precision (+0.01 mm), used for weighing of fish drop, bullet, medical instrument, * projectile; 0.1mm-10 mm precision (+0.1mm), used for oil drilling balance, * projectile.