Cr⁶⁺ and Pd Free Metallization of Plastics

Plating on plastics (PoP) is widely used in the automotive, electronics, and home appliance industries to enhance mechanical strength, corrosion resistance, and aesthetic quality. Polymer surfaces must be pretreated to enable the electroless deposition of a Ni-P conductive layer, which in turn provides the necessary foundation for the subsequent electroplating steps. Conventional industrial processes typically employ hexavalent chromium (Cr⁶⁺) based etching solutions, which are highly toxic and carcinogenic, along with activators containing palladium (Pd), which is considered as critical raw material and presents significant economic challenges due to its high cost.

This study provides a sustainable and cost-effective alternative to PoP by replacing chromic acid etching with environmentally benign acidic solutions and substituting Pd with Ni for activating ABS, PC-ABS, and Nylon-12 surfaces. Surface chemical modifications, morphology and adhesion were evaluated using FT-IR, water contact angle measurements, SEM-EDX and pull-off adhesion tests. The results demonstrated that uniform, thin and well-adhered Ni-P conductive layers can be deposited on all three polymer substrates. Moreover, the technology was successfully applied to real components with complex geometries that are used in aerospace, home appliances and automotive applications, highlighting its practical viability and reinforcing its contribution to greener surface-coating processes.