Powder metallurgy components feature a porous structure with fine surface pores. During degreasing, pickling, activation, and electroplating processes, solutions readily penetrate these pores yet prove difficult to thoroughly rinse out. Residual liquids gradually seep out during post-plating storage and usage, causing corrosion of both the plating layer and substrate material, leading to quality defects. In severe cases, localised plating failure may occur during electroplating itself, whilst also contaminating the plating bath.

Our company employs an organic solvent impregnation sealing method followed by electroplating, significantly enhancing the electroplating yield of the finished products.

Product Process:

Raw material forming → Sintering → Oil impregnation processing → Ultrasonic cleaning → Drying → Heat treatment → Ultrasonic cleaning → Drying → Organic solvent impregnation → Sandblasting → Ultrasonic cleaning → Electroplating → Oil impregnation → Final inspection.

I. Raw Materials

Seventy per cent of the raw materials utilised by our company are imported. The materials currently employed for plating components are sourced from Höganäs in Sweden.

II. Forming

Conventional powder metallurgy forming processes are employed for pressing, yielding product densities of 6.8–7.2 g/cm³. Generally, for a given material, higher product density correlates with superior plating results.

III. Sintering

Sintering is performed in a mesh belt sintering furnace at temperatures ranging from 1100°C to 1160°C. Our company utilises furnaces imported from Taiwan, specifically the Yongsheng brand, which offer stable sintering temperatures and superior sintering performance, significantly benefiting the product's electroplating process.

IV. Oil Immersion

Products undergo immersion in rust-preventative oil to prevent corrosion during machining. For non-machined items, post-sintering heat treatment or direct pore sealing yields superior results.

V. Machining

Products undergo turning, grinding, milling, drilling, tapping, or finishing processes according to specifications.

VI. Ultrasonic Cleaning

Cleaning products using ultrasonic agitation with hydrocarbon cleaning fluid to ensure uniform colour during heat treatment.

VII. Drying

Removing residual cleaning fluid from within the product.

VIII. Heat Treatment

Employing vacuum heat treatment furnaces for quenching and tempering processes to achieve customer-specified mechanical properties.

IX. Ultrasonic Cleaning

As quenching leaves residual oils affecting pore sealing, products undergo ultrasonic cleaning with hydrocarbon solvents.

X. Drying

Removes residual cleaning solution from product interiors.

XI. Organic Solution Impregnation

Vacuum equipment impregnates products with organic solvents, which are then cured at approximately 90°C to seal capillary pores.

XII. Sandblasting

Treadmill sandblasting machines are employed to remove residual organic resins from the product surface.

XIII. Ultrasonic Cleaning

Products undergo ultrasonic cleaning with hydrocarbon solvents to maintain surface brightness and enhance electroplating adhesion.

XIV. Electroplating

Electroplating is applied to the product in the sequence: copper, then nickel, and finally chrome. This electroplating process ensures a lustrous finish.

XV. Oil Immersion

The electroplated product is immersed in tin oil to enhance rust resistance.

XVI. Final Inspection

The finished product undergoes dimensional and visual inspection.