Combination of electrophoretic and electroless depositions to fabricate Ni/TiC cladding

Abstract

ABSTRACT A novel method is established that improves the shortcoming of embedding low volume fraction of reinforcements in Ni–P electroless coating. Experimental design of the present study is based on 5 steps: (1) electrophoretic deposition (EPD) of titanium carbide core inside the Ni–P shell particles (2) pre-sintering of as-EPD layer (3) electroless deposition of Ni–P top layer on as-EPD layer (4) heating the multilayer structure and (5) infiltration of the Ni–P melt phase through porous EPD layer. Anchoring TiC particles inside a Ni–P shell was done for catalyzing electroless Ni–P deposition on as-EPD layer and improving the high-temperature wettability of the EPD layer. By infiltration sintering on EPD layer (20 V for 2 min) a composite coating of Ni–P/TiC with a volume fraction of ∼49% TiC was successfully produced. According to wear test results, embedding TiC into Ni–P significantly increases hardness (972–1460 VHN) and reduces friction coefficient (0.45–0.23).