Effect of Cu addition on microstructure, texture and magnetic properties of 6.5 wt% Si electrical steel

•Cu addition up to 0.7 wt% increases B50 due to the formation of η-fiber texture.•Adding ≤ 0.5 wt% Cu decreases the iron loss as an increase in the final grain size.•Large numbers of ε-Cu form with Cu addition ≥ 0.7 wt%, reducing the final grain size.•The optimum Cu addition range for 6.5 wt% Si electrical steel is 0.3 – 0.5 wt%.