Industrial Application Products

BOROPAK is ready to use Bronoizing Mixture specially developed for bronzing of metals and alloys.

Fundamental principles of boronizing :

Boronizing or Boriding is a surface enrichment treatment involving changes in the composition of surface of metals. Boronizing is a thermo chemical process in which boron atoms diffuse and subsequently absorb into the substrate forming boride of the base metal. On steel components, bronzing results into the formation of Fe2B with or without the presence of an overlay of Fe2B layer. The composition and morphology of the boride layer depends on the composition of the base metal and the bronzing process. The boride layers thus formed adhere excellently to the base metal and are characterized by high hardness and excellent resistance to wear, corrosion & oxidation.

Boronizing can be uniformly applied to irregular shapes. Moreover, boronizing can be selectively applied to only the area that requires hardening. The surface parts, which are not to be bronzed, can be covered with an adhesive copper strip. However, boronizing temperature should not exceed 930oC in such cases.

An important point must be noted that boronizing results into surface growth depending on the composition of the base metal. Where the dimensional accuracy is essential, the work piece must be undersized during manufacture since the boride layer will add 10-30% of its thickness to the size of the work piece. For example, a 100-micron thick boride layer would have a growth of 10 to 30 micron on the base metal.

Surface degradation limits the service life of many engineering components, the major damage mechanisms being wear and corrosion. This problem can be overcome either,
(a) by selecting alternate better materials, which are more expensive, or
(b) by altering the surface characteristics by appropriate surface modification treatment.
The latter option is more economical and efficient.

Materials suitable for boronizing:

• All ferrous metals and alloys like carbon steel, low alloy steel, tool steel stainless steel, carburized steel, hardened steel, air hardening tool steel ductile and grey iron & steel, sintered iron & steel armco (commercially pure) iron etc.
• Non-ferrous metals like titanium, tantalum, tungsten, and molybdenum.
• Nickel based alloys.
• Cobalt based alloys.
• Sintered carbides.