Effect of electroless copper plating on microstructure, properties and interface of MWCNT-Cu / Ti composites

Electroless copper-plated multiwalled carbon nanotube-reinforced titanium matrix (MWCNT-Cu/Ti) composites were prepared by spark plasma sintering (SPS). The microstructure evolution, interface characteristics and properties of the composites, including strength and corrosion resistance, were investigated. The results showed that the surface impurities and structural defects of the MWCNTs were successfully removed, and the oxygen-containing functional groups such as-OH, and -COOH were introduced by acid functionalization. The structure of the electroless-plated Cu layer is that of crystalline Cu. The precipitation of TiC phases by the interface reaction of the MWCNT-Cu/Ti composites is prevented. The compressive strength of the MWCNT-Cu/Ti composites was 2303 MPa, which is approximately 2 times greater than that of pure Ti. The corrosion resistance decreased in the order MWCNT-Cu/Ti > MWCNTs/Ti > pure Ti. The orientations of [112̅0]α-Ti//[11̅0]TiC, (1̅100)α-Ti//(11̅1)TiC in the MWCNTs/Ti composites and Ti2Cu(2̅00)//Ti(1̅100), Ti2Cu (211) //Ti(1̅010) in the MWCNT-Cu/Ti composites are related.