Microstructure and properties of Ti/TiBCN coating on 7075 aluminum alloy by laser cladding

Ti/TiBCN coatings were fabricated on the 7075 aluminum alloy by laser cladding. The influence of TiBCN content on microstructure, micro-hardness, electrochemical corrosion and wear resistance of the cladding coatings were studied by SEM, XRD, Vickers micro-hardness tester, a typical three-electrode electrochemical workstation and straight-line-reciprocating dry sliding wear tester, respectively. The results showed that, when TiBCN content was 15 wt%, the microstructure of coating zone mainly composed of equiaxed grains and white lath-like crystals and that of transition zone mainly consisted of the elongated dendrite crystals and white small particles. Furthermore, the average hardness of the Ti/TiBCN cladding coating is 750HV0.2, which was about 5 times higher than that of the substrate (~ 127HV0.2), and the corrosion potential (Ecorr) reached − 1.271 V and the corrosion current density (Icorr) was 3.155e− 005 A/cm2, which was one magnitude low than that of the substrate (2.269e− 004 A/cm2). The narrow and shallow plowing grooves uniformly distributed on the worn surface and have less wear damage and the mass loss of the cladding coating was only 2.4 mg in 20 min.