The effect of Ti additions on the microstructure and magnetic properties of laser clad FeNiCr/60%WC coatings

FeNiCr/60%WC (wt) coatings with different Ti additions were deposited on P550 substrate by laser cladding to improve their nonmagnetic properties. The microstructures and chemical and phase compositions were examined using SEM, TEM, EDS and XRD, and the magnetic properties were measured using a Lake Shore7410 vibrating sample magnetometer. The results show that the addition of 1.0-4.0 wt.% Ti could reduce the magnetism of FeNiCr/60%WC coatings to varying extent, depending on the content of Ti added. The relative permeability decreases at first with the increasing Ti additions, reaches a minimum of 1.006 when 2.5 wt.% Ti is added, and then increases with further increasing Ti additions. The XRD, SEM and TEM results show that the phase constitution of the FeNiCr/60%WC coatings with different Ti additions mainly include γ-(Fe,Ni), WC, W2C and Fe3W3C, and a small amount of TiC, FeCr and (W,Ti)C1 − X. In addition, a small amount of Fe2W is observed in the coatings where Ti additions are above 4.0%. Fe2W is ferromagnetic with a total magnetic moment of 3.3924 calculated by empirical electron theory (EET) that can affect the nonmagnetic properties of FeNiCr/60%WC coatings.