However, due to the limitations of PM processing, components have a tendency towards porosity, restricting the types of corrosion protection available to coat these products. The chemicals involved in the electroplating process, for example, would be absorbed into the pores and then leach out following the process to attack both the base material and the coating.
Sherardizing, however, is a hot diffusion process which forms a uniform deposit over the whole surface of even irregular shaped articles, sealing the surface pores, thus creating an ideal method of protection for PM components.
Sifam Ltd. actuator pole pieces used in volt meters and ammeters.
Sintered timing ring for Jaguar cars
Sintered metal cam housing for the Saab brake caliper. The Sherardizing deposits follow the intricacy of the formed shape exactly.
Why use Sherardizing?
The table below shows why Sherardizing is a better choice when choosing a coating for sintered metal products.
Coating Properties Comparison:
| Type of Coating | Coating Properties |
| Sherardizing | Ideal |
| Hot Dip Spin Galvanizing | Non uniform in coverage, endangering the functionality of the component |
| Mechanical Plating | Not suitable, since the process involves chemicals that can be retained in the pores of the metal |
| Organic Coating Magni – Delta Protekt | Not suitable, since the surface adhesion is questionable |
| Zinc Electroplating | Not suitable, since the process involves chemicals that can be retained in the pores of the metal |
Other Bodycote Metallurgical Coatings services include:
| Abrasion Resistant Coatings | Chrome Seal | Low Friction Coatings |
| Advanced Coatings | CoatAlloy™ Coatings | Passivation |
| Anti-fouling Coatings | Decorative Coatings | Plasma Spray Coatings |
| Anti-coking Coatings | Diffusion Coatings | Sacrificial Coatings |
| Anti-rusting Coatings | Duplex Coatings | Surface Protection |
| Anti-seizure Coatings | Engineering Coatings | Surface Sealants |
| Carbide Coatings | Erosion Resistance | Thermal Diffusion Coatings |
| Ceramic Densification | Flame Spray Coatings | Tribological Coatings |
| Ceramic Overlay | Hard Coatings | Wear Resistant Coatings |
| Chrome Densification | HVOF |
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