The raw material of sintered parts is always metal powder. The material properties to be achieved determine the chemical composition of the powder.
Metal powder can be pure metal (iron, copper) or alloy powder (bronze, brass, steel, etc.). There are different kinds of powders (spongy, irregular, spherical, laminar flow), which give the components specific characteristics.
Depending on the composition of the material (e.g. graphite, nickel, copper, etc.), the base powder is mixed with different alloying elements, and organic solid lubricants (necessary for compacting the powder) are added, and sometimes special additives are added.
The result is a powder mixture with uniform additive distribution. Ensuring the chemical composition of a material through a rigorous dosing and control process is critical to achieving the mechanical, physical or chemical properties of the material.
The powder mixture is compacted in the mold, which has the negative shape of Xingtai sintered parts. The tool is a very high precision and high durability component.
Die assembly and maintenance are carried out through related technology.
The powder mixture is filled into the tool chamber of the mixer by gravity and a uniaxial pressure of 200 to 1500 MPa is applied according to the density to be achieved.
The compacted parts are ejected from the tooling to form "green parts", which have certain mechanical strength and can be transported.
Through the statistical process control of the unique characteristics of the parts, the compression process is guaranteed statistically.
Sintering is a thermal cycle that involves heating the compacted part at a temperature lower than the melting point of the base metal for a given time.
High temperature leads to the welding between particles, and alloy elements are formed by solid diffusion mechanism.
Sintering is carried out in a continuous furnace in an atmosphere of controlled speed and controlled chemical composition.
Sintering usually works at temperatures between 750 and 1300 ℃, depending on the material and the characteristics to be achieved.